鸟类的古老重复,共同进化和选择在MHCIIA和IIB类基因中
Piotr Minias1, Scott V Edwards2,3, Wiesław Babik4
1University of Lodz, Faculty of Biology and Environmental Protection, Department of Biodiversity Studies and Bioeducation, Lodz, Poland.
Frontiers in immunology
|November 15, 2023
概括
发现了两种古老的鸟类主要基因相容性复合体 (MHC) -IIA基因系 (DAA1和DAA2),反映了MHC-IIB系 (DAB1和DAB2). 这表明共进化和鸟类免疫反应的潜在专业化.
科学领域:
- 进化免疫学的进化免疫学
- 进行比较的基因组学.
- 鸟类生物学 鸟类生物学
背景情况:
- 据认为,鸟类主要基因相容性复合体 (MHC) 通过协同进化进化,导致基因同质化和失去了正统性.
- 然而,古老的鸟类MHC-IIB基因系 (DAB1和DAB2) 表明,ortology可以在长时间的进化过程中持续存在.
研究的目的:
- 使用基因组资源,研究鸟类MHC-IIA基因中的古老重复.
- 为了比较鸟类MHC-IIA和MHC-IIB基因系的遗传分布和选择压力.
主要方法:
- 分析了来自230多种鸟类的MHC序列,这些鸟类代表了大约70个家族.
- 遗传学分析用于识别和比较基因谱系.
- 在分子水平上进行选择分析.
主要成果:
- 发现了两种古老的鸟类MHC-IIA基因系 (DAA1和DAA2),其遗传分布与MHC-IIB系 (DAB1和DAB2) 相匹配,表明了紧密的共同进化.
- DAA1和DAA2的早期分歧是由积极选择驱动的,在膜-近接域的氨基酸差异可能会影响MHC-II异构体相互作用.
- 在结位的特异性选择差异表明,尽管没有选择的整体放松或强化,但对不同的病原体进行了专业化.
结论:
- 鸟类MHC-IIα和β链的特定配对可能具有适应性意义.
- 这一发现促进了对鸟类MHC-II宏观进化的理解,并提出了新的研究途径.
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