Department of Molecular and Cellular Biology of the Institute of Chemical Biology and Fundamental Medicine, SB RAS, Novosibirsk, 630090, Russia.
Chromosome Res. 2011 May;19(4):549-65. doi: 10.1007/s10577-011-9210-y. Epub 2011 May 11.
Glires represent a eutherian clade consisting of rodents and lagomorphs (hares, rabbits, and pikas). Chromosome evolution of Glires is known to have variable rates in different groups: from slowly evolving lagomorphs and squirrels to extremely rapidly evolving muroids. Previous interordinal homology maps between slowly evolving Glires were based on comparison with humans. Here, we used sets of chromosome-specific probes from Tamias sibiricus (Sciuridae), Castor fiber (Castoridae) and humans to study karyotypes of six ground squirrels (genera Marmota and Spermophilus) and one tree squirrel (genus Sciurus), mountain hare (genus Lepus), and rabbit (genus Oryctolagus). These data supplemented with GTG banding comparisons allowed us to build comparative chromosome maps. Our data showed the absence of previously found squirrel associations HSA 1/8 and 2/17 in the Eurasian ground squirrels--sousliks and woodchucks, and disruptions of squirrel HSA 10/13 and HSA 8/4/8/12/22 syntenies in the four Spermophilus species studied here. We found that the karyotypes of Sciuridae and Leporidae are highly conserved and close to the Rodentia ancestral karyotype, while Castoridae chromosomes underwent many more changes. We suggest that Lagomorpha and Sciuridae (in contrast to all other rodent families) should be considered as core Glires lineages, characterized by cytogenetically conserved karyotypes which contain chromosomal elements inherent to karyotype of common Glires ancestor. Our data allowed us to further refine the putative ancestral karyotypes of Rodentia. We also describe here the putative ancestral karyotypes of Glires and lagomorphs.
鼠兔类代表了一个有胎盘类哺乳动物的分支，包括啮齿目动物和兔形目动物（野兔、兔子和鼠兔）。已知鼠兔类哺乳动物的染色体进化在不同的群体中具有不同的速率：从进化缓慢的兔形目动物和松鼠到进化非常迅速的鼠科动物。以前在进化缓慢的鼠兔类哺乳动物之间进行的种间同源性图谱绘制是基于与人类的比较。在这里，我们使用来自西伯利亚旱獭（松鼠科）、河狸（海狸科）和人类的染色体特异性探针集，研究了六种地松鼠（Marmota 和 Spermophilus 属）、一种树松鼠（Sciurus 属）、高山野兔（Lepus 属）和家兔（Oryctolagus 属）的核型。这些数据与 GTG 带型比较相结合，使我们能够构建比较染色体图谱。我们的数据表明，以前在欧亚大陆地松鼠（草原犬鼠和土拨鼠）中发现的松鼠同源染色体 HSA 1/8 和 2/17 以及在这里研究的四种松鼠中破坏的松鼠 HSA 10/13 和 HSA 8/4/8/12/22 同线性并不存在。我们发现，松鼠科和兔形目动物的染色体组非常保守，与啮齿动物的祖先染色体组接近，而海狸科的染色体发生了更多的变化。我们认为，兔形目动物和松鼠科（与所有其他啮齿动物家族相反）应该被视为核心的鼠兔类哺乳动物分支，其特征是细胞遗传学上保守的染色体组，其中包含共同的鼠兔类哺乳动物祖先染色体组中固有的染色体成分。我们的数据使我们能够进一步细化啮齿动物的假定祖先染色体组。我们还在这里描述了鼠兔类哺乳动物和兔形目动物的假定祖先染色体组。
