Genetic mechanism in hybrid sterility of the mouse

小鼠杂交不育的遗传机制

基本信息

批准号：
05680746
负责人：
MATSUDA Yoichi
金额：
$ 1.34万
依托单位：
National institute of Radiological Sciences
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

项目摘要

In our initial sutdies (1992) we observed high frequency of X-Y dissociation (X//Y) at first meiotic metaphase (MI) in sterile (C57BL/6 X M.spretus) F_1 males, and that in the backcross progeny the X//Y trait segregated as a single gene which was linked to a distal locus on the X chromosome, Amg. To examine the role of pseudoautosomal region (PAR) in X-Y pairing and male feritility we produced congenic lines that carried the spretus PAR on the C57BL/6 (B6) background or the converse of B6 PAR onto the spretus host. The progeny with either high X//Y and small testis size or low X//Y and large testis size segregated almost 1 : 1 in each succeeding backcross generation, and the bimodal distribution was completely correlated with the segregation of the distal X chromosome gene marker, TeloXY.Furthermore, fertile progeny with low X//Y and homozygous PAR-type were found in mating M.spretus males with female miece of the congenic line, this result showing that the genetic divergence of PAR is … More a major contribution to the male sterility observed in interspecific hybrid males.Spermatogenesis is arrested in earlier stage of primary spermatocytes and any first meiotic metaphase are not observed in (B6 X M.macedonicus) F_1 males. To examine genetic mechanism of male sterility in the hybrid, we examined X-Y dissociation and sterility in backcross males from fertile F1 females crossed with C57BL/10. Three types of progeny were found as follows : progeny with no MI and small testis size, high X-Y dissociation and small testis size, and low X-Y dissociation and large testis size. This result indicates that there are one or two autosomal factors, which controls hybrid sterility, in addition to the pseudoautosomal region.Chromosomal segregation was analyzed in 80 (B6 X M.spretus) F_1 X M.spretus progeny and 70 (B6 X M.spretus) F_1 X B6 progeny using FISH analysis with a major satellite DNA probe (pMR196). The results suggested that there was not primary deviation from random assortment during meiosis in the interspecific hybrid female, because nearly all of the 190 pair-wise comparisons did not deviate from expected and because there was no consistent pattern of deviation of the same chromosomes in the reciprocal backcross progeny from similar (C57BL/6 X M.spretus) F_1 hybrid females. Less

在我们最初的研究（1992）中，我们观察到不育（C57BL/6 X M.spretus）F_1雄性在第一次减数分裂中期（MI）时X-Y解离（X//Y）频率较高，并且在回交后代中X/ /Y 性状分离为单个基因，与 X 染色体 Amg 上的远端基因座连锁。 X-Y 配对和雄性育性我们产生了在 C57BL/6 (B6) 背景上携带 spretus PAR 或在 spretus 宿主上携带 B6 PAR 的同系系，后代具有高 X//Y 和小睾丸尺寸或低 X。 //在随后的每个回交代中，Y 和大睾丸大小几乎以 1:1 分离，并且双峰分布与远端 X 染色体基因标记的分离完全相关， TeloXY. 此外，在 M.spretus 雄性与同类系雌性小鼠交配中发现了具有低 X//Y 和纯合 PAR 型的可育后代，这一结果表明 PAR 的遗传差异是对在种间杂交雄性中观察到雄性不育。精子发生在初级精母细胞的早期阶段被阻止，并且在（B6）中没有观察到任何第一次减数分裂中期为了检查杂种中雄性不育的遗传机制，我们检查了可育 F1 雌性与 C57BL/10 杂交的回交雄性的 X-Y 解离和不育性，发现了三种类型的后代：无 MI 的后代。和小睾丸尺寸，高X-Y解离和小睾丸尺寸，以及低X-Y解离和大睾丸尺寸。该结果表明存在一或两个。除了伪常染色体区域之外，还控制杂交不育的常染色体因素。使用 FISH 分析对 80 个 (B6 X M.spretus) F_1 X M.spretus 后代和 70 个 (B6 X M.spretus) F_1 X B6 后代进行染色体分离结果表明，在种间杂种的减数分裂过程中，不存在随机分类的主要偏差。雌性，因为几乎所有 190 个配对比较都没有偏离预期，并且因为在来自相似 (C57BL/6 X M.spretus) F_1 杂种雌性的相互回交后代中，相同染色体没有一致的偏差模式。较少的