The mitochondrial genome of the sperm whale and a new molecular reference for estimating eutherian divergence dates
The mitochondrial genome of the sperm whale and a new molecular reference for estimating eutherian divergence dates
复制标题
DOI：
10.1007/s002390010060
复制
发表时间：
2000-06-01
影响因子：
3.9
通讯作者：
Janke, A
中科院分区：
文献类型：
--
作者：
Arnason, U;Gullberg, A;Janke, A
现存的鲸目动物被系统地分为两个亚目：须鲸亚目和齿鲸亚目。在这项研究中，我们对齿鲸（抹香鲸）的完整线粒体（mt）基因组进行了测序，并将其与先前测序的两种须鲸（长须鲸和蓝鲸）和许多其他哺乳动物（包括五种偶蹄类动物（河马、牛、羊、羊驼和猪））的完整 mtDNA 一起纳入系统发育分析。最有力支持的鲸头鲸关系是：外群，((猪，羊驼)，((牛，羊)，(河马，(抹香鲸，(须鲸)))))。正如之前对完整线粒体DNA的分析一样，河马和鲸鱼之间的姐妹群关系得到了强有力的支持，使得偶蹄目和猪形目（猪、西貒和河马）都是并系系。此外，分析还确定了Suina（猪）和Tylopoda（羊驼）之间的姐妹群关系，尽管这种关系没有得到强有力的支持。须鲸类和齿鲸类的古生物学记录一直延伸到渐新世，这表明须鲸类和齿鲸类谱系在距今 32-3400 万年前就出现了分歧（MYBP）。利用这个分歧日期以及抹香鲸和两只须鲸的完整线粒体DNA，可以建立一个新的分子参考O/M-33，用于确定其他真兽类分歧的年代。 O/M-33 和之前建立的两个真兽参考文献 A/C-60 和 E/R-50 之间存在总体一致性。鲸目动物（鲸鱼）起源，即河马和鲸目动物之间的分歧，被确定为大约 55 MYBP，而偶蹄类的基础分歧被确定为大于或等于 65 MYBP。第三纪真兽类分歧的分子估计与化石记录一致。
Extant cetaceans are systematically divided into two suborders: Mysticeti (baleen whales) and Odontoceti (toothed whales). Tn this study, we have sequenced the complete mitochondrial (mt) genome of an odontocete, the sperm whale (Physeter macrocephalus), and included it in phylogenetic analyses together with the previously sequenced complete mtDNAs of two mysticetes (the fin and blue whales) and a number of other mammals, including five artiodactyls (the hippopotamus, cow. sheep, alpaca, and pig). The most strongly supported cetartiodactyl relationship was: outgroup,((pig, alpaca),((cow, sheep),(hippopotamus,(sperm whale,(baleen whales))))). As in previous analyses of complete mtDNAs, the sister-group relationship between the hippopotamus and the whales received strong support, making both Artiodactyla and Suiformes (pigs, peccaries, and hippopotamuses) paraphyletic. In addition, the analyses identified a sister-group relationship between Suina (the pig) and Tylopoda (the alpaca), although this relationship was not strongly supported. The paleontological records of both mysticetes and odontocetes extend into the Oligocene, suggesting that the mysticete and odontocete lineages diverged 32-34 million years before present (MYBP). Use of this divergence date and the complete mtDNAs of the sperm whale and the two baleen whales allowed the establishment of a new molecular reference, O/M-33, for dating other eutherian divergences. There was a general consistency between O/M-33 and the two previously established eutherian references, A/C-60 and E/R-50. Cetacean (whale) origin, i.e., the divergence between the hippopotamus and the cetaceans, was dated to approximate to 55 MYBP, while basal artiodactyl divergences were dated to greater than or equal to 65 MYBP. Molecular estimates of Tertiary eutherian divergences were consistent with the fossil record.