Walt Eanes is a Professor in the Department of Ecology and Evolution. He received his Bachelors degree from Cornell University, a Masters degree in Marine Science from the College of William and Mary and his Ph.D. from the Department of Ecology and Evolution at Stony Brook. He is a member of the graduate program in Ecology and Evolution and the graduate program in Genetics at Stony Brook. He is a former member of the GENETICS and EVOLUTION Editorial Boards. His funding is from the National Science Foundation and the National Institutes of Health.

walter@life.bio.sunysb.edu

Current Graduate Students

Stephen Sabatino

I study the genetic architecture of adaptation in species of shad found between Northern Africa, Iceland and the Caspian Sea.  Some of the shad species I focus on spend their entire life in the sea while others are isolated in freshwater lakes or are anadromous.  Many of them also exhibit remarkable genetic and phenotypic differences across several environmental gradients that are associated with ecological factors such as temperature and salinity.  This biological system therefore allows me to test hypotheses about the role metabolic genes, such as malic enzyme, play in ecological adaptation and speciation, particularly in cases where parallel evolution across similar environments has occurred.  Currently, I am utilizing next generation sequencing technologies to investigate the transcriptome of shads, which will enable me to identify metabolic genes that may be under natural selection.  

I am interested in the dynamic interaction between functional and evolutionary causation in biology.  As a second year Ph.D. student in the Eanes Lab, I am able to examine this dynamic relationship from a combined experimental biochemical and population genetic approach using energy metabolism in Drosophila melanogaster as a study system.  I am conducting preliminary work for three topics: (1) Enzyme kinetics of clinally varying metabolic genes, where derived variants are hypothesized to confer temperate adaptation, (2) Population genetics of chromosomal inversion breakpoints and linked genomic regions including experimental investigation of recombination rates, (3) Evolutionary rate variation in metabolic networks, specifically the bias towards adaptive substitutions in enzymes catalyzing reactions from a common substrate pool (branch point enzymes). Beyond these projects, I am developing interests in a variety of topics including evolution of species range limits, metabolic control analysis, and quantitative genetics.

Erik Lavington

Current Postdoctoral Associates

Matt Talbert

Obesity is a complex disease that affects ~30% of adults in the United States. In humans, obesity confers shortened lifespan and strong predisposition to comorbidities, such as cardiovascular disease, type 2 diabetes, and some forms of cancer.  Characterized by an excess body mass for a given body size, obesity arises from an overly positive metabolic balance, in which the intake of caloric energy chronically exceeds the usage of caloric energy.  Obesity has a strong genetic component, which has been indicated by high heritabilities for adiposity phenotypes, evolutionary rationales for predisposing genetic variation, and the existence of Mendelian or experimental disease models. 

During my doctoral work, I participated in early efforts to identify genes and polymorphisms underlying adiposity phenotypes in ethnic minorities of the US through such efforts as genome-wide linkage scanning in extended families, genome-wide association analysis, and dense SNP mapping.  An observation from such studies was that genetic predisposition to obesity from common polymorphisms largely stemmed from genes affecting neural control of energy homeostasis (ex. FTO, MC4R, NGEF, RGS6) or those with pleiotropic transcriptional effects downstream of major hormonal signals such as insulin or leptin (ex. INSIG2, SOCS3).  Furthermore, common genetic variants seemed to contribute relatively little genetic variance in adiposity traits in contrast with expectations.  Rare genetic variants, on the other hand, are just beginning to be explored, and both the extent of phenotypic impact in humans and the genomic locations of such variants are unknown. 

It follows that in the Eanes Lab, I utilize Drosophila melanogaster to explore the relevance of energy sensors, those genes acting just after nutrient intake to control metabolic flux, as the actions of these genes ultimately induce adjustments in energy homeostasis and transcriptional profile.  In the context of diets of varying nutritional composition (ranging from dietary restriction to obesogenic), does genetic variation (experimental or evolutionary) of agents in the central metabolic pathway impact the lifespan of a fly?  Does genetic variation in members of the central metabolic pathway impact the ability of a fly to store energy in metabolite pools or affect body size?  How key is tissue-specific expression of central metabolic genes within neurosecretory cells (and the action of said cells) in the ability of genetic variation in such genes to impact longevity, body size, and energy storage?  I am also interested in epistatic interactions between central metabolic genes exhibiting such genetic effects and those in known neural pathways of relevance.  To investigate the above questions, we use gene knockouts, RNAi, and cell ablation of neurosecretory cells, in combination with direct observation of longevity, time to starvation, triglyceride and glycogen stores, and body size in Drosophila melanogaster.  In addition, we will utilize a population genetics approach in collections of Drosophila melanogaster ranging in origin from the Northeastern US to Florida, to also study naturally-arising genetic variation in central metabolic gene activity.

Rodrigo Cogni

I have a broad interests in evolutionary biology and ecology. To study fundamental questions in these fields I use insects. Besides being the the most diverse group of animals in the planet, insects are extremely easy to be studied in the laboratory and in the field, allowing for the development of integrative and multi-disciplinary research programs. I have studied natural history, ecology, behavior and evolution of insects, including my Ph.D. dissertation work on coevolution in an insect plant system. I am currently a postdoctoral associate at the Eanes’ lab. We are looking for clinal patterns in frequency of amino acid polymorphisms in natural populations of D. melanogaster from the East Coast. These patterns of clinal variation may be the result of selection for adaptation to cold environments. We are particularly interested in genes involved in reproductive diapauses and nutrient sensing. In another project, we are studying evolution of metabolic flux control. We are trying to understand possible causes of genetic dominance and excess capacity for flight perfprmance in the glycolytic pathway. 

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