BIOCHEMICAL CHARACTERISTICS OF COLLAGENS FROM MARINE-INVERTEBRATES WITH SPECIAL EMPHASIS ON POLYCHAETA AND VESTIMENTIFERA FROM DEEP-SEA HYDROTHERMAL VENTS

The amino acid compositions of the cuticular collagens of five polycha ete species (Arenicola marina, Nereis diversicolor; Alvinella pompejan a Alvinella caudata, Paralvinella grasslei) were compared using the Ma tsamura method revised by Murray et al. (1982). These results show the biochemical diversity of their cuticular collagens. We did not find a ny correlation between the amino acid composition of the cuticular col lagens and the taxonomic position of the species investigated. Further more, there is no correlation between this composition and the type of habitat of the animals. In contrast with the cuticular collagens, all the interstitial collagens from polychaete species cluster in the sam e expected area. Thus, together these data indicate that vent annelid collagens do not exhibit any original biochemical characteristics when compared to that of coastal species. The cuticular collagen of the ve stimentiferan Riftia pachyptila cannot be separated from the whole ann elid cuticular collagen area when the Matsamura analysis is done start ing with the constituent chain amino acid composition. The same is tru e for the vestimentiferan interstitial collagen when the method is app lied to the primary sequence of the alpha chain. These results are in favor of the close phylogenetical relationship between polychaete and vestimentiferan collagens hypothetised by Sicot et al. (1997a).