Janke A, Gemmell N J, Feldmaier-Fuchs G, von Haeseler A, Pääbo S
Zoologisches Institut, Universität München, Germany.
J Mol Evol. 1996 Feb;42(2):153-9. doi: 10.1007/BF02198841.
The complete nucleotide sequence of the mitochondrial genome of a platypus (Ornithorhynchus anatinus) was determined. Its overall genomic organization is similar to that of placental mammals, Xenopus laevis, and fishes. However, it contains an apparently noncoding sequence of 88 base pairs located between the genes for tRNA(Leu)(UUR) and ND1. The base composition of this sequence and its conservation among monotremes, as well as the existence of a transcript from one of the strands, indicate that it may have a hitherto-unknown function. When the protein-coding sequences are used to reconstruct a phylogeny of mammals, the data suggest that monotremes and marsupials are sister groups and thus that placental mammals represent the most ancient divergence among mammals.
已测定鸭嘴兽（Ornithorhynchus anatinus）线粒体基因组的完整核苷酸序列。其整体基因组组织与胎盘哺乳动物、非洲爪蟾和鱼类相似。然而，它在tRNA(Leu)(UUR)和ND1基因之间包含一段明显的88个碱基对的非编码序列。该序列的碱基组成及其在单孔类动物中的保守性，以及其中一条链上转录本的存在，表明它可能具有迄今未知的功能。当使用蛋白质编码序列重建哺乳动物系统发育时，数据表明单孔类动物和有袋类动物是姐妹群，因此胎盘哺乳动物代表了哺乳动物中最古老的分化。
