Molecular phylogeny in mytilids supports the wooden steps to deep-sea vents hypothesis

Several deep-sea mussels and their associated symbionts are able to live both on wood and on whale falls

“…Representative sequences of the different lineages of bathymodiolin mussels were added to the COI mtDNA and 28S rRNA datasets and both single gene and combined datasets were built (electronic supplementary material 2). Host trees were rooted on Benthomodiolus lignicola (Samadi et al 2007). Then, in an integrative taxonomy perspective, these primary species hypotheses were evaluated in the light of shell shapes and geographical distributions of specimens.…”

“…The domains D1, D2 and D3 of the 28S rRNA nuclear gene were also amplified for hosts, while a fragment of the 16S rRNA gene was amplified for bacterial symbionts. Polymerase chain reaction (PCR) protocols for hosts and symbionts were described in Duperron (2005) and Samadi et al (2007), respectively, as well as primers for 28S rRNA and 16S rRNA, respectively. PCR products from COI mtDNA and 28S rRNA were sequenced directly using PCR primers, while amplificates of 16S rRNA were purified on columns (Qiagen) and cloned using a TOPO cloning kit (Invitrogen).…”

“…Data on habitat preference for the small bathymodiolins are scarce, and thus no convincing evidence for ubiquity exists. Moreover, their diversity is largely unexplored and underestimated (Smith & Baco 2003;Samadi et al 2007;Duperron et al 2008b). Our first goal was thus to explore the diversity of organic fall-associated bathymodiolin mussels and to test whether some species are able to live on several types of organic substrates.…”

“…Distel et al (2000) suggested moreover that organic falls may have served as 'stepping stones' for the introduction of Bathymodiolinae to deep-sea vents and seeps. In accordance with this 'wooden step to deep-sea vents' scenario, several species associated with organic falls display a basal position in mussel phylogenies (Baco 2002;Samadi et al 2007).…”

Genetic Diversity and Evolution of Marine Animals Isolated in Marine Lakes

“…The F-and M-types of mtDNA evolved independently and two highly diverged mitochondrial genomes are retained in all male individuals. F-type mtDNA is more easily used as a genetic marker to study the phylogeny of mussels than M-type mtDNA, because it exists in both sexes, and reference sequences for Brachidontes mussels are available Foighil, 2004, 2005;Terranova et al, 2007;Samadi et al, 2007). Therefore, in the present study, maternal and paternal CO I gene sequences were first distinguished, and then the F-type CO I gene was used for the phylogenetic analysis.…”