Kobayashi M, Takahashi M, Wada H, Satoh N
Department of Biology, Faculty of Science, Ochanomizu University, Tokyo, Japan.
Zoolog Sci. 1993 Oct;10(5):827-33.
Recent studies of molecular phylogeny based upon comparisons of the partial nucleotide sequences of 18 and 28S rRNAs have suggested that the metazoa are polyphyletic, i.e., that diploblasts (poriferans, cnidarians, ctenophores, and placozoans) and triploblasts form two separated monophyletic units. In order to examine this hypothesis, we determined almost the complete sequences of small subunit (18S-like) rDNA for two poriferans and a ctenophore. Phylogenetic comparisons of the sequences, together with those of a cnidarian, triploblasts and other eukaryotes, supported the monophyly of the metazoa. Among the diploblasts, the ctenophore showed some similarities to the poriferans.
最近基于18S和28S核糖体RNA部分核苷酸序列比较的分子系统发育研究表明，后生动物是多系起源的，即双胚层动物（多孔动物、刺胞动物、栉水母动物和扁盘动物）和三胚层动物形成两个独立的单系类群。为了检验这一假说，我们测定了两种多孔动物和一种栉水母动物小亚基（类18S）核糖体DNA的几乎完整序列。这些序列与一种刺胞动物、三胚层动物及其他真核生物的序列进行系统发育比较，支持了后生动物的单系性。在双胚层动物中，栉水母动物与多孔动物表现出一些相似性。
