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Life Sciences

ALICEA-CRUZ, GIL MARIE
ALMODÓVAR, WANDA
ALMODÓVAR, JORGE
BATISTA CAMACHO
BAUTISTA, KARYM
BONILLA-VÉLEZ, JOHNNY
CABÁN, HÉCTOR
CABÁN, HÉCTOR
CABRERA, MIGUEL, A.
CABRERA, ARELYS
CANTRES, ONIX
CASTILLOVEITIA ROSA, ALMA
COLLAZO, GRETCHEN
COLÓN VILLAFAÑE, OLVIA C.
COLÓN WILMA
CORTÉS, CARLA
COSME BLANCO, WILFREDO
CRUZ, FERNANDO
CUMBA, JAIMARI
DE LEÓN DÍAZ, LEE A
DELGADO, MANUEL
ESCALONA, YMA
FAJARDO HEREDIA, DOUGLAS
FLECHA-FLECHA, SARILVETH
FLORES, JACQUELINE

FONTÁN NAVARRO, LUDALIS Z.
FONTANES, VANESSA

FONTÁNEZ, YARITZA

GARCÍA ALTIERI MAURO
GONZÁLEZ, EMANUEL
GONZÁLEZ, ISADORA
JIMÉNEZ, MARÍA
LLANES, JOAN
LLENIN, GABRIELA S.
LÓPEZ-BAQUERO, RAFAEL
MALAVEZ, YADIRA
MALDONADO, FRANCISCO
MARTÍNEZ COSME, ILYANA
McLEAN, ELIZABETH, L.
MEDINA, ÁNGEL
MEDINA, YESSICA M.
MÉNDEZ CINTRÓN, MARÍA DE L.

MÉNDEZ SILVAGNOLI MARLA
MENDOZA, KARLA
MERCADO-GARCÍA, BENJAMÍN
MORALES, NADYA

MORENO QUIÑÓNEZ, AIXADELLISE

PERDOMO, SHARLIM
POMALES-HERNÁNDEZ, GRIZEL
QUIÑONEZ, BIANCA
RESTO, KARINA
RIVERA, CAROL
RIVERA ADROVET, CARLOS
ROCHE RÍOS, MARLY
RODRÍGUEZ, MARÍA

RODRÍGUEZ, JOSÉ
RODRÍGUEZ CRUZ, EVA NILDA
RODRÍGUEZ CRUZ, EVA NILDA

RODRÍGUEZ CRUZ, SANDRA I.
RODRÍGUEZ MARCANO, BÁRBARA
ROSA MORALES, REY JESÚS
SÁEZ, LORENA
SANABRIA VALENTÍN, EDGARDO L.
SANTANA, MILDRED
SANTIAGO,  FÉLIX
SANTIAGO MARTÍNEZ, EDGARDO
SCHENK, CHRISTIAN E.
SEDA MIRÓ, JASMINE
SERRANO, YENDI
SILVESTRY, MARIENA
SOTO, ANÍBAL
SOTO RIVERA, JACKELINE
SOTO-PANTOJA, DAVID
VALENCIA-RIVERA PATRICIA
VÁZQUEZ YARED
VÁZQUEZ, RANDY
VÁZQUEZ-ACEVEDO REBECA
VEGA, MARÍA
VEGA HERNÁNDEZ, MÓNICA
VIDAL GONZÁLEZ, IVAN GABRIEL
VIERA VERA, JORGE
VILLALBA-RAMOS, NADYA YANUSKA
VILLANUEVA, ENEIDA

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ALICEA-CRUZ, GIL MARIE,  Pontifical Catholic University of Puerto Rico, MARC Honor Program Student;   Castilloveitia-Rosa, Alma Y., Biology, Pontifical Catholic University of Puerto Rico; Ruiz, Eileen; Hernández-Muñiz, Wilfredo; Biochemistry, Ponce School of Medicine

The Association Between CC16 Polymorphism (A38G) and Asthma in the Puerto Rican Population

Asthma is a chronic inflammatory disease of the airways that is characterized by airway obstruction, airway inflammation, and bronchial reactivity. It is caused by combination of genetic and environmental factors. The prevalence of asthma is increasing worldwide. The identification of genetic risk factors for asthma will help to select predisposed subjects for allergen avoidance or immunoprophylaxis measures during infancy, to define the molecular basis of clinical subtypes of the disease, and to improve its pharmacological management, targeting specific abnormalities expressed by the genes involved. Most studies on the genetics of asthma have focused on candidate genes suspected to be involved in the pathogenesis of the disease. This investigation focused on Clara Cell Secretory Protein (CC16) and its association with asthma in Puerto Rican population. CC16 is 16- KD protein primarily expressed in the respiratory tract by noncilated bronchiolar secretory cells, accounting for 7% of the total protein content in the bronchoalveolar lavage fluid. 60 asthmatic individuals were analyzed by restriction enzyme digestion of PCR product for the presence of the polymorphism (A38). There were 82 controls.  Although linkage with the CC16 polymorphism and asthma were found previously in the Australian population, our studies conclude that there is no definite link between this gene and asthma in the Puerto Rican population.

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ALMODÓVAR, WANDA; Martínez Cruzado, J.C., UPR-MAYAGÜEZ, Departamento de Biología

Contribución de los Distintos Haplogrupos en el Genóma Puertorriqueño A Través de la Línea Paterna 

El propósito a largo plazo del estudio es determinar la contribución de los distintos grupos continentales, africanos, europeos e indígenas, al genoma puertorriqueño.  Como un segundo paso siguiendo a la caracterización del DNA mitocondrial, el cual se hereda por vía materna, estamos analizando la proveniencia en la población puertorriqueña del cromosoma Y.  El cromosoma Y se hereda por la vía paterna y, al igual que el DNA mitocondrial, tiene una gran porción que nunca se recombina.  Esto permite la acumulación progresiva de mutaciones cuyo estudio, al combinarse con conocimientos sobre la distribución geográfica de los mismos, reconstruye la historia de migraciones de poblaciones humanas.  Analizamos para el cromosoma Y, usando técnicas de PCR y restricción enzimática, 14 muestras de DNA de estudiantes de la Universidad de Puerto Rico-Mayagüez, procedentes de distintas áreas de la isla como lo son Yauco, Villalba, Utuado, San Sebastián, Guaynabo, Carolina, Camuy y Caguas.  De las muestras, un 43% resultaron pertenecer al haplogrupo 1C, que comprende el 68% de los españoles y el 33% de los indios de América.  Las restantes muestras están siendo analizadas.  De éstas, un 21% parecen ser 1C y un 14% se inclina hacia los haplogrupos africanos y sur africanos, pero podrían ser europeos o sureuropeos.

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ALMODÓVAR, JORGE; Sánchez, Aixa; Diffoot, Nanette, Prof., UPR-MAYAGÜEZ, Laboratory of Virology, Department of Biology

 Determination of Encapsidation Pattern of LuIII and MvMi Chimeric Plasmid

LuIII and MvMi are single-stranded DNA viruses with palindromic termini belonging to the family Parvoviridae. Because of their ability to infect their host without apparent pathogenic symptoms, parvoviruses are considered good vectors for gene therapy. In order to determine proper protocols for future applications the mechanisms of replication of the virus must be known. Studies comparing LuIII and MvMi show an 80% identity between the genomes of the viruses. This phenomenon contrasts with the fact that 99% of the assembled MvMi particles have a negative polarity genome, while LuIII encapsidates both strands with equal frequency. In order to determine what part of the genome determines the strand to be encapsidated we have employed the use of chimeric plasmids which contain the genome of LuIII and the termini of MvMi. It is suggested that the signals necessary for replication and encapsidation reside in the termini of the viral genome, yer whether they determine the encapsidation pattern is not known. Hela cells have been transfected with CC6 to determine if the plasmid is capable of replicating and if so, which viral strand is encapsidated. Hela cells transfected with a known replicating plasmid have been used as a positive control of replication. Southern Blot analysis was employed to detect the replication of viral genome in the cells and determine the encapsidation pattern of CC6.


BATISTA CAMACHO, MIGDALIA; Gutiérrez Sánchez, Jaime, UPR-MAYAGÜEZ, Departamento Ciencias Sociales-Psicología

Demografía, Actitudes y Patrones de Movilidad de los Usuarios de Carro Público en el Área Metropolitana de San Juan

En este estudio se mira al transporte público desde la perspectiva de quienes con frecuencia viven la experiencia del carro público como modo de transporte en el Área Metropolitana de San Juan. También, el estudio es importante  para planificar y establecer cuáles características deben ser atendidas y / o consideradas para ofrecer una transferencia eficiente de los carros públicos al sistema de transporte del Tren Urbano. Los propósitos de este estudio son 1) Describir el perfil demográfico de los usuarios de los carros públicos. 2) Medir las actitudes de los usuarios de carros públicos hacia el carro privado y el carro público. 3) Conocer los patrones de comportamientos en términos de la movilidad y la accesibilidad de los usuarios de carros públicos. 4) Señalar cuáles son las áreas que este sistema de transporte público debe mejorar desde la percepción de los usuarios para proveer un servicio inter-modal eficiente. Se entrevistaron a 100 usuarios de carro público en el área de Bayamón, Río Piedras y Centro Médico.

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BAUTISTA, KARYM; Massol, Arturo, Prof., UPR-MAYAGÜEZ, Department of Biology

Studies and Identification of Microbial Infections in Lepidoptera spp., Danaus plexippus 

Danaus plexippus is the scientific name given to monarch butterflies. These butterflies, like other moths, undergo four different stages: egg, larva, pupa, and adult. One factor likely to regulate the abundance of monarchs is their interactions with natural enemies. The purpose of our research is to study and identify the causes of death in caterpillar (larva) cultivated in a butterfly garden (CasaPueblo, Adjuntas). It is thought that some microbial infection is the major cause of these abnormalities. We are trying to identify the microorganism that is causing the infection by hemolymph analysis of infected larva. Bacillus thuringiensis is the principal suspect; because this microorganism is very specific when it infects Lepidoptera spp. The isolation of a bacillus from the hemolymph of larvae demonstrates the presence of a Gram (+), endospore forming bacilli present only in infected individuals. This culture was applied to milkweeds from which the larva fed.  One of the systems was used as control which consisted of healthy larva feeding on milkweed soaked with distilled water.  The experimental system consisted of milkweed which was initially treated with a dilution of the isolated bacilli in distilled water. Our results showed a 100% death rate for the larvae feeding on infected milkweed while all larvae from non infected system developed normally.

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BONILLA-VÉLEZ, JOHNNY; Arrocho-Vega, Yanice; Ersan-Said, Sufyan; Babilonia-Marichal, Maritere; Muñiz-Perez, Darlene; Reyes-Quiñones, Tania; Jusino-Atresino, Rafael,  UPR-AGUADILLA, Natural Sciences, Natural Science

Study of Biodiversity and Foraging Behavior of Ants at Mata dePlatano Reserve in Arecibo, Puerto Rico 

At the Mata de Platano reserve, in front of the Culebrones cave in Arecibo, Puerto Rico, a study about the clasification of ant genera  and their foraging behavior took place. To collect the data we used three diferents kind of traps (bait traps, pitfall and underground traps). The bait trap experiment lasted 24 hours where every 3 hours a trap was pleced on the ground and pased 15 minutes are pick up. The pitfall traps were placed level with the surface up to seven days. and the undergroun ones just for 6 hours. After the traps were collected, they were placed in a cooler to preserve the insects, so it could arrive to the laboratory. In the the laboratory the ants are cleaned and placed on vials with etanol for preserve it. The ants were observed under a stereoscope so thy  could be classified by their genera. Betwen the most abundant genderswe found Paratrechina, Wasmannia, Pheidole and Brachymyrmex. We could observe some foraging behavior like niche partition betwen some of the genders found.

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CABÁN, HÉCTOR, UPR-HUMACAO, Department of Biology; Planas, José, Prof., UPR-AGUADILLA, Department of Biology

Determination of Allelic Variation of Immunoglobulin Vh1 Family Genes by Single Sperm Analysis

The human immunoglobulin heavy chain locus is on chromosome 14q32.3 and consists of ~120 VH gene segments, ~20 DH, 6 JH and 11 CH gene segments. One hundred and twenty three VH gene segments have been identified and are subdivided into seven families (VH1-VH7) based on their degree of sequence identity. The purpose of this project is to study the allelic variation of VH gene segments at each locus for the gene segments in the VH1 family by using single sperm cells. Semen samples will be collected from unrelated healthy donors with highly diversified genetic backgrounds to allow us to have an overview of the VH region diversification in the entire human population. Three different primers (F forward, R reverse and N nested) were designed to amplify gene segments in the VH1 family which allowed us to amplify the genic region together with 5’ regulatory elements and recombination signal sequences. Single sperm are obtained by laser microdissection. PCR with a step involving nested primers is performed to amplify specific gene segments from single cell. PCR products are purified and further sequenced to determine allelic variation between different individuals.

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CABRERA, MIGUEL, A., UPR-CAYEY, General Science Program, Ayala-Torres, Sylvette, Universidad Central del Caribe, Department of Pharmacology 

Age-associated Damage to Brain Mitochondrial DNA and In Vivo Induction of Damage after 3-NPA 

Reactive oxygen species (ROS) cause damage to DNA, primarily to mitochondrial DNA and this damage can lead to mitochondrial dysfunction. Chronic exposure to ROS has been associated with several degenerative diseases including aging, the molecular basis of which remains unknown.  Increasing evidence implicates oxidative damage to mitochondrial DNA (mtDNA) as a major contributor to the age associated loss of brain function in the mouse.  We sought to test the hypothesis that aging brain will exhibit greater basal levels of mtDNA damage than younger brain and that the mitochondrial neurotoxin 3-NPA will lead to an increase in oxidative mtDNA damage in the brain.  We used a quantitative polymerase chain reaction assay to assess the relative amounts of DNA damage in the mitochondrial genome in brain obtained from C57Bl/6 mice of different ages injected with 3-NPA and the aged matched controls.  Our results show an age associated increase in basal levels in brain mtDNA damage and that 3-NPA leads to an increase in oxidative mtDNA damage preferentially in young brains.  Our results raise the possibility for a role for mtDNA damage in brain aging and neurodegeneration.

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CABRERA, ARELYS; Quiñones, José L.; García, José E., Prof., UPR-RÍO PIEDRAS, Departamento de Biología        

Un Posible Rol de la Fibronectina en la Regeneración del Intestino de Holothuria glaberrima 

Fibronectina es una glucoproteína que se encuentra en la materia extracelular en donde lleva a cabo varias funciones asociadas a la regulación, adhesión, migración y crecimiento celular. La molécula de fibronectina tiene una secuencia conocida como RGD (Arg-Gly-Asp),  la cual es la  necesaria para el reconocimiento  por integrinas en la superficie celular, y así mantener una comunicación entre componentes de la materia extracelular y el citoesqueleto.  El pepino de mar, Holothuria glaberrima, es un invertebrado que tiene la capacidad de regenerar sus visceras luego de eviscerar las mismas. Estudios previos han demostrado que durante la regeneración u organogénesis ocurre una remodelación de la matrix extracelular, así como cambios en la composición de la misma. Uno de los procesos que aparentemente sucede en la formación del nuevo órgano  es la migración celular.  Para estudiar un posible rol de la fibronectina en la regeneración intestinal de H. glaberrima,  se trataron animales con pétidos sintéticos que compiten con la secuencia de RGD, por la interacción con integrina.  Los péptidos utilzados fueron GRGDTP ( Gly-Arg-Gly-Asp-Thr-Pro) y RGD (Arg-Gly-Asp) en concentraciones entre 0.8 – 10 mg/ml. Grupos controles fueron inyectados con una solución salina (PBS) o con un  péptido control que no compite por la secuencia de RGD. Las estructuras regeneradas se analizaron mediante inmunohistoquímica para colágeno y músculo, y se midieron la cantidad de células presentes. Los resultados preliminares indican que los animales que fueron inyectados con RGD demuestran un atraso en la formación del músculo y en la migración celular dando como indicio que la fibronectina tiene una función importante en la regeneración intestinal de equinodermos. Financiado por NSF, NIH-MBRS, AMP y la Universidad de Puerto Rico.

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CANTRES, ONIX; Colón, Wilma; Pérez-Chiesa, Ivette, Prof., UPR-RÍO PIEDRAS, Departamento de Biología

Secuenciación y caracterización parcial de los genes  Adh y Adhr de Drosophila cardini 

El gen que codifica para la enzima deshidrogenasa de alcohol (ADH) en Drosophila ha sido analizado extensamente en estudios de evolución molecular.  La enzima tiene una función importante en la detoxificación de alcoholes.   El propósito de este estudio es secuenciar los genes Adh y Adhr de la especie D. cardini para contribuir al entendimiento de la evolución del gen Adh en el género Drosophila y para describir las relaciones filogenéticas entre los miembros del grupo cardini.  Se extrajo DNA usando el GNOME DNA Kit (Bio 101).  Se utilizaron “primers” específicos para amplificar, mediante PCR, dos fragmentos que abarcan desde el exón 1 de Adh hasta el exón 1 de Adhr; y desde el exón 3 de Adh hasta el exón 2 de Adhr.   Los productos de PCR fueron secuenciados usando el equipo Automated DNA Sequencer Model ABI373A (Applied Biosystem) y el PRISM DyeDeoxy Terminator Kit.  Las secuencias resultantes fueron analizadas para describir la estructura de los genes Adh- Adhr, y describir los cambios evolutivos de la región al compararla con la de especies cercanas.  La secuencia va a ser utilizada posteriormente en la construcción de un “gene-tree” para aclarar las relaciones filogenéticas entre los miembros del grupo cardini.

Auspiciado por FIPI y Howard Hughes

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CASTILLOVEITIA ROSA, ALMA; Alicea Cruz, Gil Marie, PUCPR, Department of Biology, MARC Honor Program; Ruiz, Eileen; Hernández Muñiz, Wilfredo, Prof., PUCPR, Ponce School of Medicine, Biochemistry    

Lack of Association Between Il-4 Polymorphism (C589T) and Asthma in the Puerto Rican Population 

Asthma is a chronic inflammatory disease of the airways that is characterized by airway obstruction, airway inflammation, and bronchial reactivity. It is caused by combination of genetic and environmental factors. The prevalence of asthma is increasing worldwide. The identification of genetic risk factors for asthma will help to select predisposed subjects for allergen avoidance or immunoprophylaxis measures during infancy, to define the molecular basis of clinical subtypes of the disease, and to improve its pharmacological management, targeting specific abnormalities expressed by the genes involved. Most studies on the genetics of asthma have focused on candidate genes suspected to be involved in the pathogenesis of the disease. This investigation focused on human interleukin-4 (IL-4) and its association with asthma in Puerto Rican population. They examine a large population of asthmatics for association between the genetic variant in the IL-4 promoter (C589T) and asthma severity. 98 asthmatic individuals were analyzed by restriction enzyme digestion of PCR product for the presence of the polymorphism (C589T).  Although linkage with the IL-4 polymorphism and asthma were found previously in the Caucasian and African American population, our studies conclude that there is no definite link between this gene and asthma in the Puerto Rican population.

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COLLAZO, GRETCHEN, UPR-HUMACAO, Department. of Biology; Muller, Rafael, Prof., UPR HUMACAO, Department of Physics

Image Capture of ”Comet Cells” with an inexpensive, high-resolution CCD camera 

An inexpensive, high-resolution CCD camera is coupled to a microscope optimized for fluorescence. The system is used to capture images of snail mantle cells that have been subject to electrophoresis. The cells, which have been subjected to chemical agents, might show different types of damage to their DNA when exposed to fluorescence. It has been difficult to obtain high-resolution images of these so called “comet cells”, and very expensive microscopy/imaging systems have been required for such a task. We have succeeded in obtaining high-resolution images of DNA comet cells with an inexpensive high-resolution CCD camera optimized for astronomy coupled to a microscope optimized for fluorescence. We present the results obtained with our inexpensive system.

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COLÓN VILLAFAÑE, OLVIA C.; Martínez Cruzado, Juan C., Prof., UPR-MAYAGÜEZ, Arts and Sciences, Department of Biology

Identification of Population Specific Y-Chromosome Haplogroups to Trace Puerto Rican Ancestry 

A common interest to uncover Puerto Rican heritage has recently been addressed by the identification specific polymorphisms within the Y chromosome.  The unchanging portion of the Y-chromosome that is transmitted from father to son is only exposed to mutations that in occasions have been geographically confined known as haplogroups[1].  Usefulness of the Y chromosome for evolutionary studies has been subject to the findings of common population polymorphisms[2].  A collection of previously identified polymorphisms in the Y-chromosome was gathered in order to detect their presence within the male Puerto Rican population.  A philogenetic tree has been constructed in order to methodically test male oral samples by the use of targeted PCR reactions and enzyme restrictions.  Preliminary results indicate that 38% of the samples collected belong to the IC haplogroup, which has been identified in European or Native American populations, over Eastern European 1D and Iberian 22 groups.  Currently, 23% of the samples are being tested for 1F haplogroup by the identification of mutation in the RPS4Y locus characteristic of Native American population and PN2 polymorphism leading to haplogroup 4, which has been identified in some European and African populations.  Data presented is part of a work in progress.

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COLÓN WILMA; Cantres, Onix, Pérez-Chiesa, UPR-RIO PIEDRAS, Natural Sciences, Biology Department 

Secuenciación y Caracterización de los Genes Adh y Adhr de Drosophila cardini

El gen que codifica para la enzima deshidrogenasa de alcohol (ADH) en Drosophila ha sido analizado extensamente en estudios de evolución molecular.  La enzima tiene una función importante en la detoxificación de alcoholes.   El propósito de este estudio es secuenciar los genes Adh y Adhr de la especie D. cardini para contribuir al entendimiento de la evolución del gen Adh en el género Drosophila y para describir las relaciones filogenéticas entre los miembros del grupo cardini.  Se extrajo DNA usando el GNOME DNA Kit (Bio 101).  Se utilizaron “primers” específicos para amplificar, mediante PCR, dos fragmentos que abarcan desde el exón 1 de Adh hasta el exón 1 de Adhr; y desde el exón 3 de Adh hasta el exón 2 de Adhr.   Los productos de PCR fueron secuenciados usando el equipo Automated DNA Sequencer Model ABI373A (Applied Biosystem) y el PRISM DyeDeoxy Terminator Kit.  Las secuencias resultantes fueron analizadas para describir la estructura de los genes Adh- Adhr, y describir los cambios evolutivos de la región al compararla con la de especies cercanas.  La secuencia va a ser utilizada posteriormente en la construcción de un “gene-tree” para aclarar las relaciones filogenéticas entre los miembros del grupo cardini.


CORTÉS, CARLA;  Tossas, A.,  Departamento de Biología, UPR-RÍO PIEDRAS; Fumero, José, Escuela Graduada De Biología, Universidad de Puerto Rico; Elvia Meléndez-Ackerman, Instituto De Ecosistemas Tropicales-Biología, UPR-RÍO PIEDRAS       

Breeding System in Populations of Pitcairnia angustifolia (Bromiliaceae) 

Outcrossing rates should be favored when selection acts to reduce inbreeding depression or by virtue of maintaining high levels of genetic diversity there by increasing the evolutionary potential of the species.  Self-pollination may evolve under a number of conditions. From the ecological point of view it should be favored when the pollinators are scarce and from the evolutionary point  of view it should be favored in the absence of inbreeding depression. Local populations of  Pitcairnia angustifolia show significant differences in their pollinator abundance. Measures of reproductive success will be higher for pollinations and seeds derived from selfed pollen in P.angustifolia provided that there is inbreeding depression. Inbredding depression will be more intense in the population of Rio Abajo, but less intense or else absent in El Verde and Maricao. We tested this hypothesis by comparing the performance of plants produced by artificial self- and cross- pollination for three populations of P.angustifolia. We tested differences in treatments for fruit set, seed weight, number of seeds, seed germination and mortality.  Growth rate was also determined between treatments for each population. Paired-t test was made to determine differences between treatments among populations. We found significant reduction in the performance of selfed progeny in the population of Rio Abajo and increased fruit set of self-pollination at El Verde. There was no significant evidence to conclude that plants derived from selfed pollination express better fitness that those derived from cross pollination.

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COSME BLANCO, WILFREDO; Arroyo, Nancy; Diffoot, Nanette, Prof., UPR-MAYAGÜEZ, Department of Biology

Insertion of a Consensus Sequence of a Yeast ARS in Various Plasmids to Increase the Efficiency of Transformation of Saccharomyces cerevisiae 

The autonomous replicating sequence (ARS) confers the capacity of autonomous replication to non-replicating DNA.  The analysis and determination of the structure and function of the ARS was initially studied in S. cerevisiae. Previous studies indicate that the presence of an A/T rich sequence, 47 bases long, in parvovirus LuIII could function as an ARS - like sequence (unpublished results). The 47 base pair sequence was inserted into a vector derived from puc19, pGN3, which has the URA 3 gene from S. cerevisiae as an auxotrophic marker. The resulting clone, named pURA-LuA/T, was shown to transform yeast cells and replicate autonomously. In comparative DNA studies of the parvovirus LuIII and a yeast ARS consensus sequence (5’ - T/A TTTA T/C A/G TTT T/A - 3’) a 10 base pair sequence (TTTTATTATTTT) was found to have a near perfect match (91 %) with the yeast consensus sequence. The 10/11 sequence in LuIII, located downstream of the A/T rich sequence was inserted into the pURA-LuA/T, transformation of this clone. These resulted in variable results in terms of the colony morphology. My specific role in this project is to attempt to insert an 11/11 sequence into previously constructed plasmids to try to increase the efficiency of transformation of S. cerevisiae. This 11/11 will be inserted into pURA-Lu88-100 (pGN3 with maps units 88–100 of the LuIII genome) and pURA-LuA/T. The plasmids have been digested with Bam HI. The 11/11 sequence was inserted into the respective plasmids and ligated accordingly. Once constructed, the plasmids were used to transform competent E.coli DH5a. The DNA of the resulting transformants were separated by gel electrophoresis and transferred for Southern Analysis.  Clones containing the appropriate units will be used to transform  S. cerevisiae with the clones above and study the efficiency of transformation.

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CRUZ, FERNANDO, UPR-MAYAGÜEZ, Artes y Ciencias,UPR-MAYAGÜEZ; Gregory, Meredith; Pérez, Víctor; Ksander, Bruce Schepens, Eye Research Institute, Harvard Medical School

Role of Membrane and Soluble Fas Ligand in Corneal Immunity


CUMBA, JAIMARI, UPR-CAYEY, Biology; Ferrer, Ivan, Ph.D.; Serrano, Adelfa E., PhD., Department of Microbiology and Medical Zoology, UPR-School of Medicine, San Juan

Plasmodium yoelii and Plasmodium berghei: Identification of Point Mutations Associated with mdr1 Gene 

Amplification, mutations, or overexpression of th pfmdr1 gene have been associated with multiple drug resistance in some strains of Plasmodium falciparum.

In order to better undertand the role of the mdr genes in drug resistance, we are using the in vivo murine malaria models P. berghei and P. yoelii. The objectives of our research are to characterize the mdr1 gene and to determine its relationship with drug resistance.

In this research the investigators used PCR reaction to amplified mdr1 gene from P. yoelii and P. berghei genomic DNA. These fragments were cloned and DNA sequence determined and analyzed. Preliminary experiments suggest that there are no point mutations in mdr1 genes related to drug resistance in any of the P. yoelii and P. berghei resistant lines.


DE LEÓN DÍAZ, LEE A; Rodríguez, Armando, Prof., UIA-BAYAMON, Artes y Ciencias, Departamento de Ciencias Naturales y Matemáticas

Patrones de Actividad y Selección de Alberge del Murciélago de los Techos (Molossus molossus) 

El propósito de la investigación es determinar los patrones de actividad del murciélago Molossus molossus y las condiciones térmicas del alberge.  Para esto se realizó un conteo de los murciélagos a la hora en la que salen, en una casa donde el techo es de zinc, ubicada en el barrio Higuillar de Dorado.  Se midió la temperatura en el albergue de manera continua y se estudió el comportamiento del murciélago a diferentes temperaturas en una incubadora.  Molossus molossus busca las temperaturas más bajas en su albergue y su patrón de salida está asociado a la puesta del sol. 

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DE LEÓN DÍAZ, LEE A; Rodríguez, Armando, Prof., UIA-BAYAMON, Artes y Ciencias, Departamento de Ciencias Naturales y Matemáticas

Identification of Cross-Reacting Antigens between Plasmodium falciparum and Ascaris suum 

Plasmodium falciparum a parasitic protozoan of the blood, is the cause of a terrible disease, with a high number of cases and mortality known as Malaria.  In the endemic areas were Malaria can be found, it can co-exist with other parasitic infections endemic in the same region, as in the case with the intestinal nematode of man Ascaris lumbricoides. Since it is well known that Ascaris lumbricoides share many antigenic components with  other species of parasitic organisms, and is quite difficult to obtain samples from persons infected with this parasite; instead were using the intestinal nematode of  pigs Ascaris suum

The life cycle of both Ascaris lumbricoides and Ascaris suum are quite similar, eggs are ingested, the larvae migrate to the lungs, after two weeks are re-ingested and the adults live in the small intestine. 

Both share common antigenic components, and Ascaris suum is easily obtained from slaughterhouses. The purpose of this study is the identification of homologous antigenic components between Plasmodium falciparum and Ascaris suum. SDS-PAGE, Western blot and Silver Stain Techniques were used to attain this. The advantage of identifying the antigenic components shared between Plasmodium falciparum and Ascaris suum can help to identify specific components, so a more sensitive diagnostic procedure could be applied in the future.    

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DELGADO, MANUEL; Suárez, Melvin; Quiles, Yasmín; Puente Rolón, Alberto, Prof., UIA-ARECIBO, Departamento de Ciencias y Tecnología

Comparison of External Bacterial Flora between Newborns and Adults of the Puerto Rican Boa (Epicatres inornatus

The Puerto Rican boa (Epicrates inornatus) is the largest native species of snake in the Island.  This species was included in the federal list of endangered species in October 13, 1970.  Sterile swabs and phosphate buffered saline (PBS) were used to take samples from the ventral, cloacae, oral (in adults) and dorsal area, using aseptic techniques.  The identification process of microorganisms was throughout biochemical tests and rapid identification systems such as Micro Scan and Enterotube.  A total of forty-seven bacteria were found at this moment in adults and newborns of the Puerto Rican Boa. The most common bacteria found was Staphylococcus and Bacillus, between others. It is important to emphasize that larger quantities of bacterium were found on the dorsal and cloacal area.  Identification still in process.

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ESCALONA, YMA; Barbosa, Juan M., Prof., UIA-BAYAMON, Arts and Sciences, Department of Natural Sciences and Mathematics

Identification of Cross-Reacting Antigens Between Plasmodium falciparum and Ascaris suum

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FAJARDO HEREDIA, DOUGLAS; Bendezú, Pedro, Prof., UIA-METRO, Artes y Ciencias, Departamento de Biología

Micropropagación en  Violeta Africana

Con esta investigación se pretende instruir y enseñar a la audiencia estudiantil  y la particular de los procedimientos adecuados  que requiere una micropropagación en este caso de la  violeta Africana.

Para comenzar se necesitó  buscar la solución adecuada a la  planta.  A pesar de que en el mercado se consigue el alimento liquido para la misma no se siguió con ese parámetro y se comenzó  a hacer   distintas  formulas  con diferentes micronutrientes  y macronutrientes de las cuales se obtuvieron once.

 El 11-10-01 se colocó cada pistilo de la planta en las once soluciones para entrar en observación. El 22-10-01 se comenzó a observar raices en la solución cinco y cinco dias después en solución nueve. Con esto se verificó el mejor “stock”y se prosiguió  a  concentraciones altas y bajas para tener alta eficacia de la preparación del  agar-agar se está manteniendo en la actualidad en ésta observación y   para la fecha de marzo se pretende haber conseguido la micropropagación para dicha exposición y a la vez continuar con la investigación durante todo el año para tejidos de cultivo y la forma de  que la comunidad tome provecho .

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FLECHA-FLECHA, SARILVETH; Tremblay, Raymond L., Prof., UPR-HUMACAO, Ciencias Naturales, Departamento de Biología

Vigor del Híbrido en un Cruce Entre Dos especies de Orquídeas, Lepanthes rupestris y Lepanthes woodburyana en Medios Asimbióticos

La hibridización en orquídeas, se da como una práctica con fines mayormente comerciales y también para estudios biológicos. Un híbrido es el resultado de un cruce de dos especies o variedades diferentes. Para determinar si un híbrido en orquídeas del género Lepanthes tiene mayor vigor que las especies parentales, se realizó un cruce entre Lepanthes rupestris y Lepanthes woodburyana. Estas semillas fueron sembradas en medio asimbiótico para observar su crecimiento y se comparó con un cruce entre dos individuos de Lepanthes rupestris y dos de Lepanthes woodburyana. Las semillas de las especies parentales fueron sembradas por separado y todas fueron observadas por un periodo de 6 meses. Los resultados obtenidos sugieren que existe mayor vigor del híbrido.

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FLORES, JACQUELINE
; Barbosa, Juan M., Prof., UIA-BAYAMON, Arts and Sciences, Department of Natural Sciences and Mathematics

Identification of the Secretory – Excretory Components of Ascaris suum

Ascaris suum (A. suum) is a parasitic nematode whose adult stage lives in the pig intestine. Unlike females, whose size is 40 cm. the size of the males is of 15 – 25 cm. Its life cycle is very similar to that parasitic nematode present in human beings, Ascaris lumbricoides. Once the infective eggs are ingested, the larvae lodge in the small intestine. Immediately, after the larvae perforate the intestinal wall, they pass to the circulatory system and are transported to the lungs. In the lungs they suffer a molt, mature after two weeks in the lung’s tissue and are re – ingested. Finally, they develop as adults in the small intestine, completing their life cycle.

The purpose of this research relies on the Identification of the Secretory – Excretory (S/E) Components of A. suum. The adults were obtained from pig’s intestines that were sacrificed in the slaughterhouse La Muda, in Caguas, P.R. Once in the laboratory, the adults were rinsed several times with 0.85% saline solution and then their uterus were dissected with the purpose of obtaining their fertilized eggs. These were dispersed in the same solution with 1 – 2% of Formaline to avoid contamination and growth of other microorganisms. In a period of two weeks we observed the different stages of the eggs development.

Subsequent to the larvae’s development, these were rinsed with sterile 0.85% saline solution and were homogenized to obtain its soluble products by extracting at 4  C overnight (WLE: Whole Larvae Extract). The larvae were cultured for two weeks in sterile saline to obtain the S/E products.

The WLE and the S/E were analyzed via the SDS – PAGE technique. Future analysis will involve infecting mice with the infective eggs, inoculating intramuscular tissue with the WLE and the S/E products to obtain their serum and analyze the patterns via the Immunoblot technique.

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FONTÁN NAVARRO, LUDALIS Z.; Seda Miró, Jasmine; Pérez Santos, Noemí, UPR-ARECIBO, Department of Biology; Méndez, Abel, Prof., UPR-ARECIBO, Department of Physics and Chemistry

Planetary Microbial Ecology: Microbial Growth Kinetics in Near-surface Planetary Environments

Microorganisms are subject to extreme physical fluctuations at short spatial and temporal scales in natural environments. Factors such as temperature, humidity and radiation levels affect their survival and growth rates. In particular, daily temperature oscillations of soils control microbial growth rates. Most experiments regarding this issue have been done under constant laboratory conditions. Here we report preliminary experiments and techniques to measure the growth rate of bacteria under the temporal influence of natural physical variables. We are constructing an experimental setup to continuously measure the growth rate of bacteria exposed to the daily natural temperature fluctuations of soils but otherwise enclosed in nutrient rich batch cultures. A laser-based technique will be used to monitor the optical density of the culture medium  at some shallow depth. We already tested this technique with success in the laboratory by measuring the growth rate of E. coli at many constant temperatures. The experiments will generate growth curves for some bacteria during one or more days in the soil. We will attempt to model their growth rate under such conditions. We also plan to extent our model by simulating other planetary conditions in the laboratory to estimate the habitability of other none terrestrial surfaces such as Mars. This is important to estimate backward and forward contamination risk between Earth and other planetary bodies.

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FONTANES, VANESSA, UPR-MAYAGÜEZ, Arts and Sciences; Margaret, Zupancic, Plant and Microbial Biology, University of California – Berkeley; Hofmeister, Antje, Plant and Microbial Biology, University of California – Berkeley

Mechanisms by which Chromosomal Gene Position Regulates Cell-Cell Communication in Bacillus subtilis Sporulation

Sporulation in Bacillus subtilis involves communication between the two cells involved in the process, the forespore and the mother cell.  This communication is essential for establishing the program of mother cell-specific gene expression.  Activation of the mother cell transcription factor sE is linked to sF activity in the neighboring forespore by means of a signal transduction pathway initiated by sF-directed transcription of the spoIIR gene.  It has been shown that chromosomal gene position of spoIIR affects the timing and level of activity in the neighboring cell.  A strain was constructed by moving the spoIIR gene away from its normal position, causing a delay in sE activation, and consequently, a deficiency in sporulation.  This strain was subject to chemical mutagenesis, selected for its ability to sporulate, and screened for sE activity.  Cells were also fixed for microscopy to determine formation of disporics.  Mutants were classified into two groups:  mutants with partially restored sporulation that retain defects in activity which indicate that a defect in sE activity does not necessarily cause a sporulation deficiency; and mutants whose sporulation defect is not fully accounted for by disporics.  This second group suggests the possibility of a chromosomal misorientation which causes genes to be transcribed at different times than normally, generating other sporulation defects than disporic formation.

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FONTÁNEZ, YARITZA; González, Lisandy; González, Millie; Hernández, Carmen; Casillas, Lilliam, UPR-HUMACAO, Biology Department;   Nieves, Deborah, UPR-HUMACAO, Microbiology Department

A Novel Bacillus isolated from the Cabo Rojo Solar Salterns 

Analysis of the several salt ponds located in the Cabo Rojo saltern indicated a large concentration of commonly limiting nutrients such as phosphorous and nitrogen and significant chemical oxygen demand (COD).  From such productive ecosystem we cultured a variety of aerobic organisms using plates supplemented with different concentrations (from 5 to >30%) of NaCl.  In the plates supplemented with 5 - 15% NaCl the most abundant organisms were spore formers from the Bacillus genus.  One of the bacilli cultures exhibited distinctive colony morphologies that were characterized by highly elevated colonies.  Phylogenetic characterization of our isolate indicated a 98% identity to B. licheniformis.  Further characterization of the colonies by transmission electron microscopy indicated the production of an exo-polymeric substance.  We are currently characterizing the chemical nature and function of this polymeric substance. 

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GARCÍA ALTIERI MAURO; Lázaro Pena, María; Vega Sepúlveda, Yaritza; González Vargas, Carlos I., UPR-RIO PIEDRAS,  College of Natural Sciences,  Department of Biology

Understanding the Role of the HRP1/DSE Complex in the Nonsense-Mediated mRNA Decay Pathway in Saccharomyces cerevisiae

The rate of protein synthesis in eukaryotes is determined by multiple regulatory events at different levels of gene expression. mRNA turnover plays a major role in determining the final level of a protein. Many studies have demonstrated that mRNA turnover and translation are intimately linked. One pathway that clearly exemplifies this link is the nonsense-mediated mRNA decay (NMD) pathway. In both prokaryotes and eukaryotes, nonsense mutations in a gene can accelerate the decay of the mRNA transcribed from that gene. In Saccharomyces cerevisiae, several factors and sequences involved in this pathway have been identified. Results from these studies have demonstrated that, in addition to a nonsense-codon, downstream sequence elements (DSE) located 3' from the stop codon are required to promote NMD pathway. Further, mutations in UPF1, UPF2, and UPF3 result in an increased accumulation of nonsense-containing mRNAs while having no effect on the abundance of most wild-type transcripts. More recently, we have identified the RNA binding protein, Hrp1p, as a factor that directly interacts with the DSE and modulates the activity of the NMD pathway. These results led us to propose a model for the mechanism of NMD. Based on these results, we are further characterizing, at both the molecular and biochemical levels, the role of the HRP1/DSE complex in the NMD pathway. In addition, we are currently investigating several putative DSEs located in the 3’-untranslated region of the CYC1-512 transcript. The results from these experiments will help us determine how the NMD pathway recognizes and degrades aberrant mRNAs. 

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GONZÁLEZ, EMANUEL; Martínez, Juan C., Prof., UPR-MAYAGÜEZ, Department of Biology

Contribución Étnica al Acervo Genético del Cromosoma Y en la Población Puertorriqueña

Polimorfismo en el cromosoma Y de lo seres humanos es utilizado como un marcador para rastrear el origen de ciertas poblaciones. Este cromosoma es heredado entre los varones de esa población. En este proyecto utilizamos estos polimorfismos para determinar los orígenes genéticos en la población puertorriqueña por la línea paterna.  Se conoce que la población puertorriqueña es una mezcla de varias poblaciones (caucásica, indígena y africana).  Estos métodos nos permiten estimar la aportación genética en el linaje paterno de los puertorriqueños de estos grupos continentales. Al realizarle la reacciones de PCR para amplificar ciertos fragmentos diagnósticos de cromosoma Y de Puerto Rico y ser cortados con diferentes enzimas de restricción se puede determinar si existe en ese cromosoma alguna mutación característica de algún haplogrupo. Los haplogrupos dan información importante sobre el origen continental del cromosoma Y. Aún se estan realizando pruebas para poder lograr este objetivo.  Sin embargo, la tendencia de las muestras es que muchas de estas son del haplogrupo 1C el cual se encuentra en el 68% de los españoles.

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GONZÁLEZ, ISADORA, UPR-CAYEY, Department of Biology; Heetae, Kim; Yongmin, Liu; Powel, Brown, Breast Center, Baylor College of Medicine, Houston, TX

Estrogen Can Induce Gene Expression in MCF7 Breast Cancer Cells by Activating the AP-1 Transcription Factor 

The Activating Protein-1 (AP-1) complex is a critical regulator of transcription that induces the expression of various genes controlling cell proliferation, differentiation and transformation. In breast cells, the AP-1 transcriptional factor is activated by growth factors such as estrogen, IGF, EGF and heregulin. Estrogen can activate gene through one of two pathways: the classical pathway, in which estrogen binds to the estrogen receptor, and the complex binds to the ERE promoter, or the nonclassical pathway, in which estrogen binds the estrogen receptor, and this complex then binds to the AP-1 transcription factor complex triggering AP-1 dependent transcription. According to this hypothesis; estrogen can stimulate both pathways. To determine whether the two pathways are activated by estrogen in breast cancer cells, I measure ER-dependent and AP-1 dependent gene expression in estrogen treated MCF7 cells. To measure estrogen-induced gene expression I starve MCF7 cells of estrogen and transfected with two different constructs: ERE-luc and Col-Z-luc. ERE-luc has a estrogen receptor binding site in its promoter, and therefore measure activation of the “classical pathway”.  I then transfected the cells with the Col-Z-luc construct. Col-Z-luc has an AP-1 binding site in its promoter, and therefore measure activity of the nonclassical Pathway. I stimulated the cells with estrogen or with vehicle (EtOH) for different time periods (0h, 12h, 24h) and then measured the Luciferase activity in cell lysates using the Dual Luciferase Reporter Assay (Promega). A Renilla Luciferase construct (PRL-tK) was also co-transfected and Renilla activity was measured and used to normalize the data.

The results of these study showed in the classical pathway a higher activity of transcription with the stimulation of estrogen and in the nonclassical pathway a low activity of AP-1 transcription. Estrogen can induce the ERE-dependent gene expression and the AP-1 gene expression by the classical.

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HERNÁNDEZ, ROSALIE; Serrano, Yolanda, Prof., UIA-BAYAMON, Arts and Sciences, Department of Natural Sciences and Mathematics

Determinación de Propiedades Antibacteriales del Latex de Euphobia milii, Ficus benjamina y Allamanda cathartica 

El latex es un compuesto secundario producido por numerosas angiospermas en células especializadas llamadas laticíferos. Esta substancia lechosa es una mezcla de compuestos químicos que incluyen proteínas, azúcares, sales minerales, alcaloides, aceites y otros. Se cree que su función es la de proteger la planta contra depredadores y sellar heridas producidas a ésta. La mayoría de los latex son irritantes a nuestra piel y algunos pueden ocasionar la muerte si son ingeridos. Se utilizó el latex de Euphorbia milii (corona de Cristo), Ficus benjamina (ficus) y Allamanda cathartica (canario amarillo). Las bacterias Bacillus cereus, Bacillus subtilis, Klebsiella pneumoniae, Escherichia coli, Enterobacter aerogenes, Micrococcus luteus, Pseudomonas aeruginosa y Staphylococcus aureus fueron analizadas con el propósito de observar si el latex exhibía propiedades antibacteriales en éstas. Se usaron céspedes bacterianos, dilución en serie y curva de crecimiento para determinar si el latex inhibía el crecimiento bacterial. Además se usó la técnica de gota colgante para determinar si el latex afectaba el movimiento bacterial. No se observó inhibición en ningun césped bacteriano tratado con los diversos latex. En su lugar se observó una mayor  cantidad de baterias alrededor del disco impregnado con el latex. Pseudomonas aeruginosa y M. luteus fueron las bacterias más afectadas en su movimiento por el latex de F. benjamina y E. milii respectivamente. Se observó una fase logarítmica más lenta en la curva de crecimiento de la bacteria de E. coli tratada con el latex de E. milii.

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JIMÉNEZ, MARÍA; Semidey, Marisol; Figueroa, Maricelys; Ortiz, Almarie; Asencio, Carmen, Prof., PUCPR, Departamento de Biología         

Biología Reproductiva de Zamia pumila L. 

Zamia pumila es la primera especie de Zamia descrita por Lineo en 1763.  Es una especie caribeña, limitada al centro de Cuba, República Dominicana y al sur de Puerto Rico.  El objetivo de este trabajo preliminar es determinar la fenología reproductiva de Z. pumila.  El área de las canteras del barrio Cuevitas en la carretera #PR552 en Juana Díaz se visitó dos veces al mes durante el período de agosto a diciembre de 2001.  Se identificaron las plantas y se coleccionaron los siguientes datos: número de conos por planta, largo y ancho de los conos, sexo, producción de semillas y abortos.  Los resultados hasta ahora indican que Z. pumila puede producir entre uno y cuatro conos rojizo-marrones por planta.  Además se ha encontrado una tasa muy alta de abortos, mayor de 90%.  Esta alta tasa de abortos podría, entre otros factores explicar su limitada distribución en Puerto Rico.

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LLANES, JOAN, UPR-MAYAGÜEZ, Arts and Sciences, Department of Biology; López, Joseph P.; Clark, Emily S.; Shepherd, Virginia L., Vanderbilt University, School of Medicine, Pathology, Deparment of Veterans Affairs

The Effect of Surfactant Protein-A on Mycobacterial Clearance in Murine Alveolar Macrophages

Surfactant protein A (SP-A) is an important component of the innate immune system. SP-A acts as one of the first lines of defense against microbial invasion in the lungs. It has been demonstrated previously that SP-A enhances the clearance of Mycobacterium bovis Bacillus Calmette-Guerin (BCG) by means of enhancing BCG ingestion and nitric oxide (NO) production in rat bone marrow-derived macrophages (RBMM). Since BCG infection is localized in the lungs, it is important to conduct the experiments in alveolar macrophages to further examine the physiological roles of SP-A. A murine alveolar cell line known as MH-S is thought to be a possible candidate for this study. MH-S cells were treated with BCG and BCG pre-opsonized with SP-A to measure the amount of NO produced. Surprisingly, the cells did not produce NO in response to the treatments. The MH-S cells were then treated with fluorescently-labled BCG opsonized or not with SP-A. While BCG was readily taken up by the cells, there was no noticeable difference of ingested BCG between the two treatments. Western blot analyses for total tyrosine phosphorylation were also done on MH-S after 5 and 15 minute treatments with BCG and BCG+ SP-A. As in the other experiments there was no noticeable difference between the two treatments, although both stimulated tyrosine phosphorylation of many proteins. The results demonstrate that the findings obtained in rat bone marrow-derived macrophages cannot be duplicated in this particular cell line.  This may be explained by the nature of the cells as virally-transformed alveolar macrophages that may not produce specific SP-A receptors and are thus unable to respond to SP-A.   

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LLENIN, GABRIELA S.; Carrasquillo, Mara Z.; Vargas, María, Prof., UPR-MAYAGÜEZ, Arts and Sciences, Department of Biology

Mycoflora Present in the Habitat Where the Tilapia spp. Live in the Center of Investigation and Development of Aquiculture of Puerto Rico 

Being decomposer of organic material, the Fungi Kingdom plays a vital role in life’s cycle, although they can affect humans, plants, and animals. Some of the Tilapia spp. in the CILAC presents symptoms that indicate its infection with fungi. The investigation proved that there are fungi present in the water and soil where the Tilapia spp. grows. We took samples of water and soil in certain ponds and used them to make dilutions of 1/100, 1/1000, and 1/10000 concentration. We placed them in petri plates with Potato Dextrose Agar, and incubated them for one week under 25ºC. With the help of slide culture, we found in the water Aspergillus glaucus group, Aspergillus niger, Cladosporium, Curvularia, Fusarium, Geotrichum, Nigrospora, Paecilomyces, Penicillium, yeasts and sterile mycelia. In the soil, only Fusarium was identified. With this investigation, we concluded that the Tilapia’s environment in the CILAC provides the ideal conditions for these fungi species to develop. It has been also proved that most of the species are common contaminants. To determine the impact of these species of fungi in the Tilapia spp., we need to study the internal organs, the skin, and the eyes of the fishes. During this semester, we are incubating some of those internal organs so that we can compare them with the obtained results. After we have reached the final results, we will know if the Tilapia that we receive is infected, or just grows in an environment along with others microorganisms, such as fungi, without getting infected.

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LÓPEZ-BAQUERO, RAFAEL; Rubin, Michael, Prof., UPR-CAYEY, General Science Program, Department of Biology

PCR Amplificaton of Gene Fragments Encoding Synapsin From Rhesus Macaca mulatta

The synapsins are a family of neuronal phosphoproteins associated with synaptic vesicles and regulate neurotransmitter release. Past studies have shown that expression of synapsins correlates temporally with synapse formation, but there has been no direct evidence that they are involved in synaptogenesis. The experimental goal of this work is to amplify synapsin specific fragments from Rhesus macaca mulatta genomic DNA. The Rhesus monkey shares many genes with humans and the synapsins have not been identified in this model organism. We designed PCR primers and used them to amplify synapsin specific gene fragments from Macaca mulatta genomic DNA. Results showed amplification of synapsin fragments required both up and down primers. Synapsin fragments were amplified from Rhesus genomic DNA and a plasmid containing rat synapsin IIb cDNA. Putative synapsin fragments 425 bp, 240 bp and 170 bp in length were detected in Rhesus genomic DNA. These fragments will be purified, cloned and sequenced. The sequence of Rhesus synapsins will help to determine the structure and function of this important gene family.

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MALAVEZ, YADIRA; Rodríguez, Fidel J.; Del Llano, Ana; Sastre, Miguel, UPR-HUMACAO, Departamento de Biología; Muller, Rafael, Departamento de Física, UPR-HUMACAO

Análisis Cuantitativo del Grado de Fragmentación del DNA Utilizando el Programa Vis Comet y el Microscopio de Epifluorecencia

El ensayo cometa es un método rápido y sensitivo utilizado para analizar daños en el DNA a nivel celular/molecular. Dos de las aplicaciones que se pueden realizar con esta técnica son la detección de rompimientos de cadena sencilla (“single strand breaks”) y la detección de apoptosis. Utilizando un microscopio de epifluorescencia clasificamos visualmente los núcleos en cuatro clases según la cantidad de DNA que ha migrado del núcleo hacia el lado positivo de la bandeja de electroforesis (esta migración se asemeja a la cola de un cometa). La clasificación está relacionada a la cantidad de rompimientos de cadena sencilla. Las células apoptóticas, detectadas sin realizar electroforesis, poseen una zona de difusión ancha muy característica. Esta técnica de clasificación visual provee un conteo rápido, económico y sencillo para detectar rompimientos de cadena sencilla y apoptosis; sin embargo, es un método cualitativo y subjetivo. El propósito de este trabajo es establecer la relación entre la clasificación visual y el análisis de imágenes computarizado. De esta manera podemos corroborar nuestros resultados visuales. Utilizamos el programa VisComet para analizar cuantitativamente la cantidad de fluorescencia observada bajo el microscopio.

En los núcleos sometidas a electroforesis encontramos que los no apoptóticos poseen mucha más fluorescencia total que los apoptóticos. En aquellos sometidos a electroforesis encontramos que la clasificación visual corresponde al porciento de DNA en la cola. Nuestro trabajo confirma que existe una relación estrecha entre el análisis visual de daño y el análisis de imágenes computarizado.

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MALDONADO, FRANCISCO, UPR-MAYAGÜEZ, Artes y Ciencias, Biotecnología Industrial; Martínez, Juan C., Prof., UPR-MAYAGÜEZ, Departamento de Biología

Análisis de Cromosoma Y Para Determinar la Ascendencia Puertorriqueña 

El puertorriqueño es producto de años de desarrollo y crecimiento e interacción de tres grupos continentales primordiales: europeo, africano e indígena.  La meta en esta investigación es determinar las contribuciones relativas de estos distintos grupos.  Para investigar la herencia puertorriqueña de estos grupos por vía paternal, estamos estudiando el cromosoma Y, el cual se transmite de padre a hijo varón.  La mayor parte de las secuencias de este cromosoma resisten recombinación.  Por tal razón, las mutaciones presentes en este cromosoma son acumulativas, permitiendo un análisis filogenético simple que al combinarse con información geográfica arroja información sobre las migraciones del Homo sapiens que lo llevaron a colonizar el planeta.  Se usa el término haplogrupo para denominar un grupo de cromosoma Y que comparten una combinación de mutaciones y por lo tanto un origen común.  Estos haplogrupos son característicos de cada grupo étnico.  Por lo tanto, la identificación del haplogrupo al cual pertenece un cromosoma Y es un primer paso a la identificación del origen de ese cromosoma.  Un total de 16 muestras de un grupo de estudiantes fueron tomadas y analizadas mediante amplificación de ciertas regiones del cromosoma Y, seguido de análisis de restricción o fraccionamiento electroforético directo para la identificar los haplogrupos a los cuales pertenecen.  Los resultados apuntan a la posible presencia de haplogrupos caucásicos y africanos en la población estudiada y a una muy escasa o inexistente presencia de haplogrupos indígenas.

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MARTÍNEZ COSME, ILYANA, UPR-CAYEY, Departamento de Biologia; Staray, Vincent, Department of Bacteriology, University of Wisconsin-Madison; Escalante-Semerena, Jorge C., Department of Bacteriology, University of Wisconsin-Madison

Elucidating the Role of cobB Sirtuin in Salmonella enterica Propionate Catabolism

The cobB was recently identifies in Salmonella enterica. We are interested in this gene because it encodes a member of the SIR2 family of proteins (aka, sirtuins). Proteins in this family play a significant regulatory role in eucaryotic gene expression. Specifically, sirtuins have enzymatic activities that are relevant to the processes of genetic silencing and cell aging. To date, no other physiological role has been assigned to these enzymes. The aim of the present study was to investigate the role of CobB sirtuin during the catabolism of propionate in Salmonella enterica. In this bacterium, this sirtuin is required for growth on propionate as the sole source of carbon and energy. In the absence of CobB, the cell fails to grow on propionate. Genetic evidence obtained in our laboratory indicated that the need for CobB can be bypassed. There appear to be least two alternative pathways. One involves propionyl kinase. The propionyl kinase-dependent pathway requires phosphotransacetylase activity encode by the pta gene, strongly suggesting that CobB is somehow involved in the conversion of exogenous propionate into propionyl_CoA. A strain carrying a deletion of the cobB gene was mutagenized to isolate derivatives of it that activated the second alternative pathway. We tested whether or not the alternative pathway required the involvement of the Pta enzyme. Our results showed that cobB revertants lacking pta function retained the ability to grow on propionate, suggesting that pta function was not part of the second alternative, CobB-independent pathway. Future work will define identify the locus affected by the gain-of-function mutations that activate the second alternative pathway. Knowledge of these functions will help define the role of the CobB sirtuins in metabolism.

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McLEAN, ELIZABETH, L.; Alston, Dallas E; Cabarcas-Nuñez, Alexis; Ojeda, Eduardo; Quintero, Herbert; García, Samuel, UPR-MAYAGÜEZ, Department of Marines Sciences

Factors Influencing Visible Patterns Present on Tropical Fish Scales

Stock assessment of marine fish is important to scientists, marine related industries, and resource administrators. Accuracy and precision are needed to estimate stock assessment of fish populations. Groupers, a tropical carnivore, are long-lived, growing slowly after they become adults. Analyses of rings formed on calcareous structures (such as otoliths) are the most frequently used method for determining their age and growth. Other methods include length-frequency analyses or tag-recapture. In temperate climates, fish scales or other bony structures usually indicate a year-mark reflecting slow growth during colder months and faster growth during warmer periods. Temperature variations are one of the strongest environmental influences on growth. However, changes are minimal in the tropics and fish scales typically do not have year-marks. Scales collected from 41 groupers (Epinephelus fulvus, coney; and E. cruentatus, graysby) caught with hook and line six km south of La Parguera indicated little variance due to seasonal changes. Of these, 29% of the scales presented obvious patterns, including marks and shadows, with some repetition within each scale. Patterns were consistent on scales pertaining to same fish. Because temperature changes are not considered to be important, other possible factors could influence secretion of growth hormones altering ring formation. These include low oxygen, fluctuating light regime, and food availability. Oxygen is abundant year-round at the collection site. The light regime, while important, is not considered to be a major contributing factor to scale growth. Food availability may not be constant, thus may be an important variable affecting growth and hormone secretion.

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MEDINA, ÁNGEL; Uscian, John, UPR-MAYAGÜEZ, Biology Department

Purification and Characterization of Trypsin From Intestinal Tissues of the Black Wing Snapper, Lutjanus buccanella 

The abundance of digestive proteases in fish digestive organs will vary with diet.  On the idea that relative trypsin abundance may therefore function as an environmental indicator, trypsin from the black wing snapper, Lutjanus boccanella, was purified and characterized via standard enzyme analytical procedures.  Using tissues obtained from fish caught by commercial anglers of Puerto Real, PR, a homogenate was produced.  Subsequent centrifufation and ammonium sulfate fractionation procedures performed on this homogenate resulted in highest trypsin activity being detected in the 50% ammonium sulfate fraction.  Current investigations are focused on purifying the enzyme from this fraction through use of Benzamidine "Hi-Trap" columns (Amersham-Biosciences), which are affinity columns specific for trypsin.

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MEDINA, YESSICA M.; Rodríguez, Sandra; Quiñonez, Edwin; Soto Vélez, Idelisse; Puente Rolón, Alberto, Prof., UIA-ARECIBO, Departamento de Ciencias y Tecnología

Densidad y Diversidad de Bacterias en la Cueva de los Culebrones, Arecibo, Puerto Rico

La presencia del ser humano en el ambiente subterráneo es uno de las fuentes inevitables de daños en las cuevas.  El propósito de este trabajo es identificar las  especies de bacterias presentes en la Cueva de los Culebrones, determinar la densidad y diversidad de microorganismos, así como la patogenicidad de los mismos con respecto a la fauna existente.  Además, nos permitirá establecer una base de datos para el monitoreo del impacto de la actividad antropogénica a largo plazo.  En total, dieciséis (16) muestras  fueron obtenidas del interior de la cueva localizada en la Reserva Mata de Plátano, Arecibo, Puerto Rico.  Hasta el presente se han identificado organismos pertenecientes a los géneros:  Klebsiella spp., Pseudomonas spp., Bacillus spp., Staphylococcus spp., Proteus spp. y Micrococcus spp.  

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MÉNDEZ CINTRÓN, MARÍA DE L.; Tremblay, Raymond L., Prof., UPR-HUMACAO, Ciencias Naturales, Departamento de Biología

Presencia de Homogamia en la Orquídea Lepanthes woodburyana, Stimson

Las orquídeas, presentan varios mecanismos para evitar la autopolinización, uno de estos es la dicogamia.  Es importante que no ocurra autopolinización, ya que esto lleva a que se reduzca la variabilidad genética dentro de una población, y se obtengan altas probabilidades de endogamia.  La protoandria es uno de los mecanismos de dicogamia, esto es cuando un organismo presenta una condición funcional masculina (androecio) antes que se desarrolle el estado funcional femenino.  Para determinar la existencia de este mecanismo, hemos realizado varias polinizaciones con flores de edades distintas, tres y seis dias.  La probabilidad de producir frutos con flores es de 14.7 por ciento en las de tres días y en las de seis días es de 16 por ciento.  Los resultados obtenidos muestran que esta especie no presenta protoandria como mecanismo de prevención de autopolinización.

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MÉNDEZ SILVAGNOLI MARLA, PUCPR, Departamento de Biología; Ricart Morales, Carlos, Prof., UPR-CAYEY, Departamento de Biología

Comparative Analysis of the Heavy Metal Presence in Water, Sediment, and Seagrass(Thalassia) Tissue in the Guayanilla and Montalva Bays. 

The study examines the heavy metal bioaccumulation and bioconcentration in the sea grass, Thalassia testudinum  in polluted areas along the Guayanilla bay (i.e., experimental site) and a less polluted area in Montalva bay (i.e., control site). Samples of water, Thalassia leaves and rhizomes, and soil sediments were taken from three stations on each area. For several decades, the area in the Guayanilla bay received different types and sources of chemical and biological pollution including discharges from  oil refineries, sewage plants and activities related to urban development.  The samples were analyzed for heavy metals detection and quantification by the inductively coupled plasma spectroscopy methodology following the protocol established by the Environmental Protection Agency (EPA). The results show that the metal concentrations obtained in the experimental area  are significantly higher than those obtained in the control area. In addition, the presence of chromium, silver, vanadium and lead was detected in the Guayanilla bay samples. The higher concentrations, of 182.5 mg/L of chromium, were found in T. testudinum  rhizomes  at la Garza station.  In contrast, the samples in Montalva Bay contained only silver, chromium and cadmium.  The higher concentrations, up to 1.07 ppm of silver, were obtained from the water samples at Frio station. Silver concentrations exceed the Environmental Quality Board water standards in both areas.

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MENDOZA, KARLA, UPR-HUMACAO, Microbiologia;   Wang Yuh-Hwa Bioquímica, UMDNJ

Clonacion de "FRA16B DNA" Para Caracterizar su Habilidad de Montar Nucleosomas

Los sitios frágiles son discontinuidades en los cromosomas y están implicados en muchos desórdenes mecánicos,  Resultados experimentales han demostrado que ciertos sitios frágiles exhiben la habilidad inherente de excluir la formación de nucleosomas.  FRA16B DNA es inducido por ciertos químicos como "distamycin A"y "berenil".  Este sitio frágil está localizado en el cromosoma 16q22.1.  El mismo, fue amplificado utilizando "Polymerase Chain Reaction"(PCR), transformado en células competentes de E. coli, purificado y analizado para determinar su preferencia en el montaje de nucleosomas.  Entendiendo hasta que punto el FRA16B DNA se enlaza con las histonas para montar los nucleosomas, nos permitira investigar si existe alguna anormalidad relacionada a este sitio frágil.

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MERCADO-GARCÍA, BENJAMÍN; Rodríguez, Carmen; Arbelo, José G., Prof., UPR-ARECIBO, Department of Biology/Microbiology

Tolerance Studies of the Strain Bacillus sp. Isolated from the Aquatic Plant Water Hyacinth in Culture Media with Trace Elements

The aquatic plant water hyacinth (Eichhornia crassipes) may be used as a sensitive biological indicator for continuously monitoring certain types of pollutants in aquatic systems. This behavior may be a result of the microbiota associated with the plant. In this study, the exposure of the strain Bacillus sp. isolated from the rhizosphere of the water hyacinth to media containing copper (Cu), vanadium (V) and arsenic species (AsIII and AsV) was evaluated in terms of the bacterium tolerance to these elements. The microorganism was exposed separately to each element at concentrations ranging from 0.635 ppm to 6.35 ppm. Biochemical tests were also performed under these conditions. The results obtained indicate that the microorganism showed resistance to Cu and V at concentrations less than 6.35 ppm, respectively. In the case of the arsenic species, the motility of the bacterium was significantly affected at the concentration of 6.35 ppm. T