Analysis of 18S rRNA gene sequences suggests significant molecular differences between Macrodasyida and Chaetonotida (Gastrotricha).
Partial 18S rRNA gene sequences of four macrodasyid and one chaetonotid gastrotrichs were obtained and compared with the available sequences of other gastrotrich species and representatives of various metazoan phyla. Contrary to the earlier molecular data, the gastrotrich sequences did not comprise a monophyletic group but formed two distinct clades, corresponding to the Macrodasyida and Chaetonotida, with the basal position occupied by the sequences of Tetranchyroderma sp. and Xenotrichula sp., respectively. Depending on the taxon sampling and methods of analysis, the two clades were separated by various combinations of clades Rotifera, Gnathostomulida, and Platyhelminthes, and never formed a clade with Nematoda. Thus, monophyly of the Gastrotricha is not confirmed by analysis of the presently available molecular data.
Manylov
Oleg G
OG
Department of Invertebrate Zoology, St. Petersburg State University, St. Petersburg 199034, Russia.
Vladychenskaya
Natalia S
NS
Milyutina
Irina A
IA
Kedrova
Olga S
OS
Korokhov
Nikolai P
NP
Dvoryanchikov
Gennady A
GA
Aleshin
Vladimir V
VV
Petrov
Nikolai B
NB
D000818:Animals; D019143:Evolution, Molecular; D006376:Helminths / Q000235:genetics*; D016013:Likelihood Functions; D009348:Nematoda / Q000235:genetics*; D010802:Phylogeny; D012337:RNA, Ribosomal, 18S / Q000235:genetics*
D012337:RNA, Ribosomal, 18S