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Molecular mechanism of meiotic control : Studies byusing hybrid-sterile organisms.

减数分裂控制的分子机制：利用杂交不育生物体进行研究。

基本信息

批准号：
08044206
负责人：
HOTTA Yasuo
金额：
$ 3.9万
依托单位：
Graduate School of Biological Sciences, Nara Institute of Science and Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

项目摘要

Most of hybrid animals are sterile in both male and female due to the meiotic failure in pairing of homologous chromosomes and the recombination. However, the hyburid between yak and cattle shows only male-sterile. The chromosomes, probably the genes also, in both male and female are apparently identical except the sex chromosomes. Thus, we have speculated that the difference in fertility in sex will come from the process for germ cells. Our study indicated (1) in sterile testes, meiotic degradation at pachytene was evident. (2) expression of meiosis specific genes, LIM 9,10,13,15,18, occured even in these degrading meiotic cells, studied by both westem method and in situ FISH method using the antibodies raised against the proteins prepared in E.coli. (3) Optical and electron microscopic studies indicated the presence of normal synaptonema complex except a few segmentations. These results indicate that meiosis proceeds until later half of pachytene normally but then fragmentation of chromosomal DNA,like ones observed in X-autosomal translocation male mice, may be induced. It is interesting to find that as male-sterility recovered by generations, F1, F2, F3 and F4 (noraml fertility) through females, parallels with the percent of normal meiotic cells present in testes and the size of the testes. The molecular mechanisms for male specific failure of meiosis remains to be studied. Nevertheles, this study made a contribution to mongolian breeding research and the basic research for meiosis.

由于同源染色体配对的减数分裂失败和重组，大多数杂种动物的雌雄都是不育的。而牦牛与黄牛的杂交后代仅表现雄性不育。除了性染色体之外，男性和女性的染色体，可能还有基因，显然是相同的。因此，我们推测，性别生育能力的差异将来自生殖细胞的过程。结果表明：（1）不育睾丸粗线期减数分裂降解明显; (2)用Westem方法和原位FISH方法研究了减数分裂特异基因LIM 9、10、13、15、18在这些降解的减数分裂细胞中的表达。(3)光学显微镜和电子显微镜研究表明，除了少数分段外，存在正常的联会复合体。这些结果表明，减数分裂进行，直到后一半的粗线期正常，但随后的染色体DNA片段，如在X-常染色体易位雄性小鼠中观察到的，可能会被诱导。有趣的是，随着雄性不育的世代恢复，F_1、F_2、F_3和F_4（正常育性）通过雌性，与睾丸中存在的正常减数分裂细胞的百分比和睾丸的大小平行。雄性特异性减数分裂失败的分子机制仍有待研究。本研究为蒙古族的育种研究和减数分裂的基础研究做出了贡献。