Journal of Oceanography, Vol. 53 (No. 2), pp. 193-197, 1997
Takeshi Naganuma1,2, Chiaki Kato2, Hisako Hirayama2, Nobuo Moriyama3, Jun Hashimoto2 and Koki Horikoshi2
1Faculty of Applied Biological Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima 739, Japan
2Japan Marine Science and Technology Center, Yokosuka 237, Japan
3Department of Urology, Faculty of Medicine, University of Tokyo, Bunkyo-ku, Tokyo 113, Japan
(Received 17 July 1996; in revised form 1 September 1996; accepted 23 September 1996)
Abstract: Endosymbionts of vestimentiferan tubeworms are generally thought to be g-Proteobacterial sulfur oxidizers. We have identified two novel 16S ribosomal RNA genes (rDNA), presumably of e-Proteobacteria, from the trophosome content of a vestimentiferan tubeworm. Phylogenetic analysis suggested that the 16S rDNAs were closely related to those of Arcobacter, most of which are known to be associated with animal hosts but are non-chemosynthetic. Intracellular localizations of the 16S rDNAs were confirmed by in situ hybridization using their specific probes. This is the first report of e-Proteobacterial 16S rDNAs associated with a vestimentiferan tubeworm.