“…On the other hand, mcrA gene has been classified into ANME-a, b, c, d, e, and f phylotypes. Recently, two newly identified mcrA gene subgroups designated as ANME-g and ANME-h have been established, in which, group g is regarded as representatives specifically adapted to terrestrial freshwater (Takeuchi et al, 2011). Through the parallel phylogenetic comparison of 16S rRNA gene and mcrA gene, corresponding relationships have been established as follows: mcrA subgroups a-b and g-h, c-d, f to be in ANME 1, 2c, 3 subtypes, respectively, while mcrA subgroup e was postulated to be in ANME-2a (Hallam et al, 2003; Lösekann et al, 2007).…”