Characterization of DNMTs in Killifish
The goal of this project is to characterize the developmental profiles of DNA methyltransferase (DNMT) genes in the estuarine killifish, Fundulus heteroclitus. DNMTs catalyze the transferof of a methyl group from S-adenosylmethionine (SAM) to cytosine. In mammals, there are three DNMTs (DNMT1, DNMT3a, DNMT3b) that play an important role in establishing and maintaining the methylation profiles. In contrast, zebrafish and killifish possess multiple copies of DNMT3 due to genome duplication and their functions are not fully understood. Killifish is an excellent model species that displays a variety of physiological adaptations to its environment. Some populations that live in highly contaminated coastal habitats have acquired heritable resistance to the toxic effects of contaminants. Evidence from recent studies demonstrate that epigenetic mechanisms play an important role in transgenerational effects of contaminants and phenotypic plasticity. Hence, the goal of this study is to characterize DNMT profiles during development and to understand the role of DNA methylation in environmental adaptation. Funding for this work was provided by WHOI Ocean Life Institute (2012)
Role of epigenetic regulation in developmental plasticity in a model cladoceran.
The objective of this study is to investigate the role of DNA methylation in the development of alternative phenotypes in response to environmental stressors. One of the excellent examples of a species with phenotypic plasticity is the water flea (Daphnia spp.). Daphnia is a commonly found crustacean in freshwater ecosystems that serves as an excellent environmental model. It exhibits distinct phenotypes in response to environmental changes and is widely used as a model species to study evolutionary basis of phenotypic plasticity. It reproduces both clonally (asexually) as well as sexually, facilitating the investigation of transgenerational phenotypes. In recent years, the availability of genomic resources has facilitated research in understanding the molecular basis of plasticity in ecologically important species. Some of the phenotypic responses have been explained by the genetic variation, and recent studies have identified epigenetic variation as a potential mechanism of action.DNA methylation is an important epigenetic mechanism and it has been shown to play a role in the establishment of developmental plasticity in honeybees. Using high-throughput sequencing we sequenced the DNA methylome of Daphnia. Results suggest that intergenic DNA methylation is more predominant as seen in other invertebrates. Funding for this project was provided by Andrew W. Mellon Foundation for Innovative Research (2012)
The objective of this proposal is to determine the effect of chronic exposure to contaminants on the metabolite profiles in Atlantic killifish, Fundulus heteroclitus. Killifish inhabiting highly contaminated Superfund sites such as Acushnet River estuary, near New Bedford Harbor (NBH), Massachusetts have evolved resistance to polynuclear aromatic hydrocarbons (PAHs). We determined the metabolite profiles to determine if the NBH fish have altered metabolic capacity which allows them to thrive in highly contaminated waters. Currently we are in the process of analyzing these results. This work will be done in collaboration with Dr. Kujawinski at WHOI FT-MS facility. Funding was provided by Joint Initiatives Awards Fund from Andrew W. Mellon Foundation (2012)