Meeting Abstract
Ghost crabs exhibit remarkable running capabilities that are comparable with similar sized mammals, and their performance is clearly dependent upon the cellular and molecular organization of their skeletal muscles. Skeletal muscle function in mammals and other vertebrates is closely linked to the specific myosin heavy chain (MHC) motors that power muscle contraction. In crustaceans, distinct fiber types are closely correlated with muscle function, but our understanding of the MHC isoforms in these distinct fiber types is more rudimentary than in mammals. We have previously identified partial sequences from ghost crabs that included the carboxy-terminus and 3’-UTR of three different MHC isoforms, but the only full-length MHC sequences known from any crustaceans are from three species of shrimp. The current project began as the central component of a research-based laboratory course, and as such represents the productive integration of authentic research with the teaching mission of a predominantly undergraduate institution. Our goal in that course was to identify the full-length sequence using 5’ RACE to clone amino-terminal ends of the MHC genes in different muscle fiber types. The sequences obtained in the class, together with the previously identified 3’ end of the genes, were used to design PCR primers to fill in the sequence gaps in these 6 kb genes. Using numerous complementary methods partial cDNA clones were generated and range from 4,400-4,800 bp and have been identified and statistically compared to other MHC gene sequences known from the shrimp. Once we complete our identification of the full length sequences of the three MHC isoforms in ghost crabs, we will compare these with the available sequences from other decapod crustaceans to better understand how these genes contribute to the ghost crab’s remarkable running performance.
