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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