Meeting Abstract

P2.85  Friday, Jan. 4  Molecular identification of an Rh glycoprotein in the gill of the Atlantic hagfish Myxine glutinosa EDWARDS, S L; Appalachian State Unviversity, Boone edwardssl@appstate.edu

In higher vertebrates ammonia is a nitrogenous waste produced by amino acid metabolism and in mammals is detoxified in the liver to urea. Teleost fish on the other hand excrete ammonia directly into the surrounding water. Recent studies have identified members of the Rh glycoprotein family in the gills of a number of teleost species. In the pufferfish Takifugu rubipes, gill Rh glycoproteins have been shown to mediate the transport of an ammonia analogue (methylammoinum) in oocyte expression systems. These results suggest that gill Rh glycoproteins may be the site of ammonia transport across the branchial epithelium, from the vascular space to the environmental water. Very little is know about the ability of the more primitive fishes, in particular the hagfishes to regulate nitrogenous wastes. In this study we have used RT-PCR to identify a member of the Rh glycoprotein family in the gills of the Atlantic hagfish. Molecular cloning has identified an 1234bp fragment of hagfish gill Rh gene that shares a 90% nucleotide identity to the RhA gene expressed in the gill of the three spine stickleback (Gasterosteus aculeatus). The functional significance of Rh glycoproteins in the gill of the osmoconforming hagfish is yet to be determined.