Privalsky Martin L, Goodson Michael L
Department of Microbiology and Molecular Genetics, College of Biological Sciences, University of California at Davis, Davis, CA, 95616, USA.
Department of Anatomy, Physiology, and Cell Biology, College of Veterinary Medicine, University of California at Davis, Davis, CA, 95616, USA.
BMC Res Notes. 2019 Jun 17;12(1):343. doi: 10.1186/s13104-019-4384-z.
The NCoR-1 and NCoR-2 corepressors are products of an early gene duplication near the beginning of vertebrate evolution and play both overlapping and divergent roles in development and physiology. Alternative-splicing of NCoR-1 and NCoR-2 further customizes their functions. To better understand the evolutionary basis of this phenomenon we extended our prior study of NCoR-1 and NCoR-2 alternative-splicing to an expanded series of species.
Alternative-splicing of NCoR-2 was observed in all vertebrates examined whereas alternative-splicing of NCoR-1 was largely limited to placental mammals. Notably the most prominent of the NCoR-1 alternative-splicing events specific to the placental lineage, in exon 37 that plays a key role in murine metabolism, mimics in many features an analogous alternative-splicing event that appeared in NCoR-2 much earlier at the beginning of the vertebrate radiation. Detection of additional alternative-splicing events, at exons 28 in NCoR-1 or NCoR-2, was limited to the Rodentia or Primates examined, indicating both corepressor paralogs continued to acquire additional splice variations more recently and independently of one another. Our results suggest that the NCoR-1/NCoR-2 paralogs have been subject to a mix of shared and distinct selective pressures, resulting in the pattern of divergent and convergent alternative-splicing observed in extant species.
NCoR-1和NCoR-2共抑制因子是脊椎动物进化初期早期基因复制的产物，在发育和生理学中发挥着重叠和不同的作用。NCoR-1和NCoR-2的可变剪接进一步定制了它们的功能。为了更好地理解这一现象的进化基础，我们将之前对NCoR-1和NCoR-2可变剪接的研究扩展到了一系列更广泛的物种。
在所有检测的脊椎动物中都观察到了NCoR-2的可变剪接，而NCoR-1的可变剪接在很大程度上仅限于胎盘哺乳动物。值得注意的是，胎盘谱系特有的NCoR-1可变剪接事件中最突出的是在第37外显子中，该外显子在小鼠新陈代谢中起关键作用，在许多特征上模仿了在脊椎动物辐射开始时更早出现在NCoR-2中的类似可变剪接事件。在NCoR-1或NCoR-2的第28外显子中检测到的其他可变剪接事件仅限于所检测的啮齿动物或灵长类动物，这表明这两个共抑制因子旁系同源物最近继续相互独立地获得额外的剪接变异。我们的结果表明，NCoR-1/NCoR-2旁系同源物受到了共同和不同选择压力的混合影响，导致了在现存物种中观察到的可变剪接的发散和收敛模式。
