Plant & Animal Genomes XVI Conference Plant & Animal Genomes XVI ConferenceJanuary 12-16, 2008
Town & Country Convention Center
San Diego, CA
Dina A. Proestou , Caitlin Vaughn , Scott Salger , Marta Gomez-Chiarri
Matrix metalloproteinases (MMPs) are zinc-dependent enzymes that degrade the extracellular matrix and are critical in developmental and immunological processes. Over twenty MMPs exist within a single vertebrate genome, complicating the study of their in vivo roles. There are fewer MMP genes in invertebrates, rendering them useful models for elucidating MMP involvement in physiological and pathological mechanisms. The goal of our research is to determine the role of MMPs in innate immunity and host-pathogen interactions in the American Oyster, Crassostrea virginica. We have isolated genes coding for two putative MMPs in oysters. The protein structure of Cv1MMP is most similar to that of D. melanogaster MMP1 and S. purpuratus MMP14. Screening of a C. virginica BAC library indicates that both CvMMPs are low copy number and that they are linked. We are currently analyzing BAC clones containing both genes to determine their relative location on the chromome and identify upstream regulatory sequences. In immunohistochemical analysis of oyster tissues, CvMMP-specific polyclonal antibodies bind to hemocytes and the epithelium of barrier tissues (mantle, digestive tract), suggesting a role in immune defenses. Temporal and tissue-specific patterns of oyster MMP production and activity are affected by infection with the protozoan parasite Perkinsus marinus. The response of MMPs to other pathogens is being examined. We have also found strain-specific SNPs within the Cv1MMP primary sequence and are investigating whether they are associated with disease resistance. By employing genomics tools in our research, we hope to shed light on the potential role of MMPs in immune defenses.