Genome-wide survey of post-meiotic segregation during yeast recombination.-猫眼课题宝

酵母重组过程中减数分裂后分离的全基因组调查。

DOI：

10.1186/gb-2011-12-4-r36

发表时间：

2011

期刊：

Genome biology

影响因子：

12.3

通讯作者：

中科院分区：

生物学1区

文献类型：

作者：

Mancera E;Bourgon R;Huber W;Steinmetz LM

来源链接：

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3218862/?report=classic

当减数分裂重组过程中形成的异双工DNA的错配没有得到修复时，减数分裂后两个错配等位基因的分离在随后的有丝分裂中发生。这在多细胞生物中引起了体细胞镶嵌现象，并导致后代之间意想不到的等位基因组合。尽管减数分裂后分离对遗传有影响，但仅在少数位点上进行了研究。通过对酵母分离体及其克隆后代中的数万个遗传标记进行基因分型，我们在全基因组范围内分析了减数分裂后的分离。我们发现减数分裂后分离发生在接近10%的重组事件中。虽然单个减数分裂中受影响的标记总数很少，但减数分裂后的分离率比碱基替换突变率大5个数量级以上。减数分裂后分离在杂交和非杂交中发生的相对频率相同，通常发生在基因转化束的边缘。此外，减数分裂后分离倾向于发生在从其他杂合子中分离出来的标记上，并且优先发生在酵母物种中相对罕见的多态性类型上。总的来说，我们的调查揭示了减数分裂后分离的全基因组特征。结果表明，减数分裂后分离在减数分裂重组中广泛存在，可能是群体水平上等位基因遗传和等位基因频率的重要决定因素。

When mismatches in heteroduplex DNA formed during meiotic recombination are left unrepaired, post-meiotic segregation of the two mismatched alleles occurs during the ensuing round of mitosis. This gives rise to somatic mosaicism in multicellular organisms and leads to unexpected allelic combinations among progeny. Despite its implications for inheritance, post-meiotic segregation has been studied at only a few loci. By genotyping tens of thousands of genetic markers in yeast segregants and their clonal progeny, we analyzed post-meiotic segregation at a genome-wide scale. We show that post-meiotic segregation occurs in close to 10% of recombination events. Although the overall number of markers affected in a single meiosis is small, the rate of post-meiotic segregation is more than five orders of magnitude larger than the base substitution mutation rate. Post-meiotic segregation took place with equal relative frequency in crossovers and non-crossovers, and usually at the edges of gene conversion tracts. Furthermore, post-meiotic segregation tended to occur in markers that are isolated from other heterozygosities and preferentially at polymorphism types that are relatively uncommon in the yeast species. Overall, our survey reveals the genome-wide characteristics of post-meiotic segregation. The results show that post-meiotic segregation is widespread in meiotic recombination and could be a significant determinant of allelic inheritance and allele frequencies at the population level.