This study will investigate the membranes, cells, tissues, and organs of crustaceans involved in heavy metal detoxification. The overall objectives of this research will be to disclose how the gastrointestinal tract, blood, and excretory system of the American lobster, Homarus americanus, isolates and eventually eliminates potentially toxic environmental heavy metals obtained in the diet. In this project, physiological and molecular biological techniques will be used to characterize the mechanisms by which heavy metals such as copper, zinc, and cadmium enter and exit gastrointestinal epithelial cells and their organelles. In addition, these studies will extend to uptake and efflux processes for metals that occur in lobster hemocytes and antennal glands (kidneys) since these other two sites are involved in the transport of metals throughout the animal and their eventual excretion to the environment and are therefore integral in the homeostatic regulation of these potentially toxic substances. Proposed molecular studies will involve the use of cloning of lobster-specific cDNAs to obtain full-length nucleotide sequences of heavy metal membrane transporter proteins. These nucleotide sequences will be compared to published analogous sequences from other organisms to determine the extent of similarity between species. Antibodies to deduced amino acid sequences will be synthesized and used in localization studies to determine the tissue and cellular distribution of detoxification mechanisms in crustacean organ systems and their potential roles in organismic metal homeostasis. These studies could have broad implications for heavy metal homeostasis in cells of all organisms since toxic properties of metals are ubiquitous phenomena. The research that will be conducted at an undergraduate research institution that has just initiated its first graduate program in Biology and will be partially used to support research activities of both undergraduate students and Master of Science graduate students. Research results from student activities will be presented at scientific conferences and published in appropriate journals.
