How and what mechanisms contribute to the interactive effect of nutritional status and arsenic toxicity?
Arsenic compounds are prevalent environmental toxicants that are also potent carcinogenic agents to humans. The metabolism of arsenic has an important role in its toxicity and there exists striking variation in individual susceptibility to arsenic-induced health effects. Nutrition is also related to arsenic toxicity, where people with poor nutrition are particularly vulnerable. The processes in which nutrition acts as a mediator of arsenic toxicity is largely unknown. The long-term goal of this project is to understand the underlying mechanics of the arsenic-nutrition interaction, and to apply that knowledge for better risk assessment strategies. We are using a novel systems biology approach to identify cellular, biochemical and metabolic pathways that facilitates the above interaction and how that relates to organismal fitness. We study the mechanistic underpinnings of these interactions in our model organism Daphnia. The rationale for the proposed research is that once these contributing pathways are identified, better risk assessment models can be developed addressing not only the arsenic-nutrition interaction but also the inter-individual variations in susceptibility.The proposed project is significant because it will initiate a more mechanism based approach for dealing with arsenic-related health effects and provide a model approach to identify similar role of nutrition in other heavy-metal induced toxicity. Funded by NH-INBRE.
Low Quality (LP) and High Quality (HP) algal food for Daphnia grown in continuous chemostat cultures
5-day old Daphnia with Arsenic (left) and without Arsenic (right)
What is the effect of phosphorus (P) loading (or eutrophication) and global warming on organismal adaptation?
This study focuses on how human-induced environmental changes affect crucial life-history traits in keystone freshwater species Daphnia pulex. In the last few decades we have seen an increase in both temperature and phosphorous (P) loading (eutrophication) in freshwater systems. Previous studies have separately looked at the effect of increased temperature and increased dietery-P content in organisms, however the combined effect of these two have not yet been tested. This project takes an integrative approach to test such interactions at the organismal level (physiological rates), molecular level (differential gene expression) and biochemical level (protein variations) to understand how such environment changes impact the survival and fitness of these organisms.
Daphnia cultures maintained at ambient temperature (20C)
Daphnia cultures maintained at stressful high temperature (28C)
How and to what extent do habitat destruction affect biogeochemical cycling of greenhouse gases on coastal estuaries?
The rising demand of the global seafood market requires an equivalent growth of aquacultural practice, resulting in significant habitat alterations of estuarine ecosystems. The overall goal of this project is to quantify the effect of oyster farming on estuarine habitats in NH Great Bay area and Ninigrit Pond in RI. This project is an extension of my postdoctoral tenure in Dr. Fulweiler’s lab in Boston University. Specifically, we are looking at the role of sediment microbial communities and how they change in response to different ages of the oyster farms. We hope to establish reliable microbial indicators of estuarine systems which in turn will provide information to farm managers on the sustainability of these practices
Sampling sediment from under the oyster cages in Great Bay Area, Durham, NH
Sediments are collected from under the oyster cages from farms of different ages (duration of farming)