Fiscal Year 1996 Awards

Minority Postdoctoral Research Fellowships

Fellow's Name Host Institution Research Area/Training Plan NSF Award #
Title of Research and Training Plan

Andrew Singson Emory University Developmental Biology 9628916
"The sperm components required for sperm-oocyte interactions in C. elegans "
The project uses several genes that when mutated produce cytologically normal and motile sperm that cannot fertilize oocytes even after contact. These mutations seem to disrupt either sperm-oocyte recognition, adhesion, or fusion. Equivalent mutants have not been described in any other metazoan. The approaches include genetic, cell biological, and molecular biological ones to gain an understanding of these genes and their mutant forms.

David Holloway University of Copenhagen Computational Biology 9628904
"Controlling errors in embryological development"
It is believed that the concentrations of spatially distributed chemicals cause the patterned differentiation of cells by causing differential responses in the genome. A mathematical model of this hypothesis will be used to evaluate the capacity of such a mechanism for suppression of the thermal fluctuations inherent in any concentration, a necessary condition for the precision of embryological patterning.

Sandra Merino Indiana University, Bloomington Prokaryotic Genetics 9628899
"Duplicated DNA sequences subjected to premeiotic methylation in a mushroom"
The mushroom Coprinus cinereus is used in this study because genes are normally present in only one copy per nucleus, duplicated sequences are methylated premetotically in crosses, and methylation effects are detectable in the veil cells of the mushroom cap. This unique organism is ideally suited for studying premiotic homology search in cell division. Genes have been isolated from the mushroom which are necessary both for survival after gamma irridation and for meiosis. These mutants are being used to study the role of MIP, methylation indued premeiotically, in meiotic chromosome pairing and synapsis.

Kelly Zamudio Univ. California-Berkely Population Biology 9628913
"Genealogical analysis of population differentiation: comparative study of montane squamate species"
The species under study are five "sky island" reptiles from southern Arizona and New Mexico that range in body size, dispersing ability, and habitat specificity. The objective of the study is a detailed understanding of patterns of genetic lineage differentiation under varying gene flow disruption regimes, using naturally separated populations.

Benjamin Ortiz Univ. California-Berkely Eukaryotic Genetics 9628911
"In vivo requirements for appropriate expression of T-cell specific genes in mice"
The locus control region (LCR) sequences of specific T-cell receptor genes confer a high level of T-cell specific expression of a linked transgene regardless of position in chromatin. The structure and function of the LCR are being determined to shed light on how the LCR exerts its powerful influence on gene expression.

Sandra Perez University of Arizona Ecology 9628909
"Ecology of a complex mutualism: measuring the costs and benefits of a well-known cactus-microorganism-Drosophila interaction"
The principle mutualism in the system under study appears to occur between Drosophila mojavensis that feed and lay eggs on "rots" caused by various yeasts and bacteria which parasitize host cacti, Stenocereus thurberi and Stenocereus gummosus. The flies likely act as vectors of infection for the microorganisms. It will be determined if the organisms provide each other with the hypothesized net benefits.

Elizabeth Torres Amr. Museum Natural History Systematic Biology 9628908
"Origin of bioluminescence in ostacode crustaceans: function and molecular evolution of luciferase genes"
Bioluminescence has evolved independently numerous times in various organisms. Some luminescent cypridinid ostracodes have a biochemically unique luciferase-lucferin system used in courtship signaling but other species lack a light producing system. These species provide a system to study the origin of the luciferase system, hypothesized to be a mutation in an oxygenase.

Tracey Takeuchi-Miller Brown University Metabolic Biochemistry 9628905
"How do chloroplasts in the cytoplasm of plant cells communicate with the nucleus?"
The proper development of plant cells relies upon this communication. The mechanisms for this communication are unclear even after many years of investigation and progress. There is evidence that signals are relayed by the chloroplast and received by the nucleus thus regulating specific genes. The project focuses on the identity of these signals.

Sharon Horton Univ. Texas, SW Medical Center Neurobiology 9628903
"The Isolation of MASH1 Expressing Cells from Transgenic Mice"
The mammalian achaete-scute homologous gene 1 (MASH1) is a neuron-specific transcription factor that identifies neural precursors in multiple lineages at early stages of development and, in some cases, is required for development to proceed. The aims are to isolate, characterize, and compare MASH1 expressing precursors using MASH1/lacZ expressing transgenic mice.

Erik Kupperman University of California, San Francisco Developmental Biology 9628901
"Mechanisms Regulating Zebrafish Heart Tube Morphogenesis"
Zebra fish will be used as a model system to study early development of the vertebrate heart. A mutant zebra fish which develops two hearts will be studied to determine how many genes are involved and if they regulate cell migration and/or adhesion. Using a variety of techniques of molecular biology, attempts will be made to identify the genes involved in heart organogenesis.

Byron Ford Harvard Medical School Intergrative Animal Biology 9628895
"Acetylcholine receptor-inducing activity in cardiac development"
The research and training plan focuses on the development of the vertebrate heart using cells cultured form chicken. A protein called ARIA known to stimulate the acetyl choline receptor in the neuromuscular junction is also expressed during early heart development This study seeks to determine the role of ARIA in early heart development and to determine the developmental expression patterns of its isoforms in this organ.

Lucinda Carnell Columbia University Neurobiology 9628892
"Genes regulating the harsh touch response in the nematode Caenorhabditis elegans"
Caenorhabditis elegans (C. elegans, an important model for the study of developmental biology) responds to harsh touch through 2 sensory neurons known as PVD. These neurons require the homeobox domain protein MEC-3 for proper development of the touch cells involved in the response. The genes involved in the harsh touch response will be isolated taking advantage of their dependence on MEC-3 and the availability of mutants which lack the harsh touch response.

Marcos Betancourt University Maryland, College Park Biophysics 9628793
"Theoretical studies of protein folding"
The thermodynamic and kinetic properties of in vitro and in vivo protein folding are being studied by computational and analytical methods using lattice and off- lattice models. The experimental problems being investigated involve protein design, chaperone mediated folding, modeling of realistic protein structures such as for cytochrome c and the analytical calculation of folding rates.

Jonathan Caguiat University of Georgia Microbial Genetics 9628798
"Protein-metal recognition: the MerR model"
The mechanism by which a bacterium survives exposure to the toxic metal mercury is being studied using the Tn21 mercury resistance operon from a plasmid of the bacterium Shigella flexeri. The study will determine how a regulatory protein, MerR, binds to DNA and induces expression of a structural gene, merTPCAD, in response to mercury exposure. It will be determined how MerR distinguishes between mercury and other heavy metals also encountered in the environment. Mutants whose MerR recognize cadmium and zinc will be generated and characterized.


Minority Graduate Student Travel Award

Melissa Bennett Universidad de Granada, Spain Systematic Biology 9633954


Minority Postdoctoral Research Fellowship Third Year Extensions

Maria Morena     9406807

Angel Paredes     9406849

Wilfredo Colon     9406859

Debbie Laudenia-Chingcuanco     9406828

Eric Yang     9406846

Elizabeth Holder     9406843

Kim Armstrong     9406857

Ivette Emery     9406862