Germline-restricted chromosome (GRC) in the sand martin and the pale martin (Hirundinidae, Aves): synapsis, recombination and copy number variation
Germline-restricted chromosome (GRC) in the sand martin and the pale martin (Hirundinidae, Aves): synapsis, recombination and copy number variation
复制标题
DOI：
10.1038/s41598-020-58032-4
复制
发表时间：
2020-01-23
影响因子：
4.6
通讯作者：
Torgasheva, Anna A.
中科院分区：
文献类型：
--
作者：
Malinovskaya, Lyubov P.;Zadesenets, Kira S.;Torgasheva, Anna A.
迄今为止研究的所有鸣禽都有一个额外的生殖系限制性染色体（GRC），这在体细胞中不存在。GRCs在遗传内容上表现出很大的差异，物种之间的同源性很小。为了检查这种分歧是如何影响GRC的减数分裂行为的，我们研究了近缘砂和淡滨鹬（Riparia riparia和R.与远亲的雌雀相比。利用减数分裂蛋白的免疫定位和与GRC特异性DNA探针的FISH，我们发现了一个惊人的相似性，尽管数百万年的独立进化的马丁斯和雌雀之间的GRC减数分裂行为。GRCs通常在雌性粗线期细胞中以两个拷贝存在，而在雄性粗线期细胞中以一个拷贝存在。然而，我们检测到多态性的女性和嵌合体的男性martins的GRCs的数量。在马丁和斑胸草雀雌性，两个GRCs突触沿着他们的整个长度，但重组占主导地位，在他们的结束。我们认为，GRC的减数分裂行为的共同特点已支持的自然选择，有利于GRC的优先分离的鸡蛋。
All songbirds studied to date have an additional Germline Restricted Chromosome (GRC), which is not present in somatic cells. GRCs show a wide variation in genetic content and little homology between species. To check how this divergence affected the meiotic behavior of the GRC, we examined synapsis, recombination and copy number variation for GRCs in the closely related sand and pale martins (Riparia riparia and R. diluta) in comparison with distantly related estrildid finches. Using immunolocalization of meiotic proteins and FISH with GRC-specific DNA probes, we found a striking similarity in the meiotic behavior of GRCs between martins and estrildid finches despite the millions of years of independent evolution. GRCs are usually present in two copies in female and in one copy in male pachytene cells. However, we detected polymorphism in female and mosaicism in male martins for the number of GRCs. In martin and zebra finch females, two GRCs synapse along their whole length, but recombine predominately at their ends. We suggest that the shared features of the meiotic behavior of GRCs have been supported by natural selection in favor of a preferential segregation of GRCs to the eggs.