Molecular phylogeny and divergence time estimates for major rodent groups: Evidence from multiple genes
Molecular phylogeny and divergence time estimates for major rodent groups: Evidence from multiple genes
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DOI：
10.1093/oxfordjournals.molbev.a003860
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发表时间：
2001-05-01
影响因子：
10.7
通讯作者：
Honeycutt, RL
中科院分区：
文献类型：
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作者：
Adkins, RM;Gelke, EL;Honeycutt, RL
啮齿目包含现存所有哺乳动物物种的一半，从进化的角度来看，围绕该目的单系性、主要谱系的分化日期以及科之间的关系一直存在争议。对多种啮齿动物和其他哺乳动物的生长激素受体（GHR）和乳腺癌易感性（BRCA1）基因的外显子进行了测序，并结合线粒体12S rRNA基因的序列以及先前发表的血管性血友病因子（vWF）的序列。啮齿动物的氨基酸替换率是非啮齿动物的两倍，这种快速的进化速度影响了分化日期的估计。基于GHR序列，单系性得到支持，豪猪型亚目与大多数松鼠型亚目之间的估计分化时间约为7500万年前。大多数估计的分化日期与化石记录相符，包括家鼠属 - 大鼠属分化的2300万年前这一日期。这些日期比从其他一些分子研究得出的日期要晚得多。在对各种基因序列的联合和单独分析中，发现几个分支得到了中等到强的支持。GHR似乎比12S或vWF具有更强的分辨能力。尽管豚鼠（以及其他豪猪型亚目动物）对生长激素完全无反应，但在GHR的细胞内结构域中表现出保守的变化率。
The order Rodentia contains half of all extant mammal species, and from an evolutionary standpoint, there are persistent controversies surrounding the monophyly of the order, divergence dates for major lineages, and relationships among families. Exons of growth hormone receptor (GHR) and breast cancer susceptibility (BRCA1) genes were sequenced for a wide diversity of rodents and other mammals and combined with sequences of the mitochondrial 12S rRNA gene and previously published sequences of von Willebrand factor (vWF). Rodents exhibit rates of amino acid replacement twice those observed for nonrodents, and this rapid rate of evolution influences estimates of divergence dates. Based on GHR sequences, monophyly is supported, with the estimated divergence between hystricognaths and most sciurognaths dating to about 75 MYA. Most estimated dates of divergence are consistent with the fossil record, including a date of 23 MYA for Mus-Rattus divergence. These dates are considerably later than those derived from some other molecular studies. Among combined and separate analyses of the various gene sequences, moderate to strong support was found for several clades. GHR appears to have greater resolving power than do 12S or vWF. Despite its complete unresponsiveness to growth hormone, Cavia (and other hystricognaths) exhibits a conservative rate of change in the intracellular domain of GHR.