The role of the SPO11 gene in meiotic recombination in yeast.
The role of the SPO11 gene in meiotic recombination in yeast.
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DOI：
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发表时间：
1985-06
期刊：
影响因子：
3.3
通讯作者：
S. Klapholz;C. Waddell;R. E. Esposito
中科院分区：
文献类型：
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作者：
S. Klapholz;C. Waddell;R. E. Esposito
几个互补的实验方法被用来证明，SPO 11基因是专门需要减数分裂重组。首先，spo 11 -1突变体二倍体的孢子形成文化的里程碑生物化学，细胞学和减数分裂和子囊孢子发生的遗传事件进行了检查。细胞以高效率进入孢子形成，并显示出DNA含量几乎加倍。联会复合体，密切的同源配对的标志，和polycomplex结构出现在减数分裂前期。虽然自发的有丝分裂基因内和基因间重组发生在正常水平，没有减数分裂重组观察。而超过50%的细胞完成减数分裂分裂，包装的四个减数分裂产物进入成熟的子囊孢子发生在只有一个小的子组的子囊。单倍体发生在不到1%的可行的集落形成单位。其次，通过对spo 13 -1单分裂减数分裂产生的孢子进行二分体分析证实了spo 11 -1所赋予的Rec-减数分裂缺陷，其中重组不是产生有活力的子囊孢子的必要条件。spo 13 -1突变纯合的二倍体经历减数分裂水平的交换，随后是一次主要的均等分裂，形成含有两个近二倍体孢子的子囊。随着spo 11 -1突变的引入，高孢子活力得以保留，而基因间重组减少了100倍以上。
Several complementary experimental approaches were used to demonstrate that the SPO11 gene is specifically required for meiotic recombination. First, sporulating cultures of spo11-1 mutant diploids were examined for landmark biochemical, cytological and genetic events of meiosis and ascosporogenesis. Cells entered sporulation with high efficiency and showed a near-doubling of DNA content. Synaptonemal complexes, hallmarks of intimate homologous pairing, and polycomplex structures appeared during meiotic prophase. Although spontaneous mitotic intra- and intergenic recombination occurred at normal levels, no meiotic recombination was observed. Whereas greater than 50% of cells completed both meiotic divisions, packaging of the four meiotic products into mature ascospores took place in only a small subset of asci. Haploidization occurred in less than 1% of viable colony-forming units. Second, the Rec- meiotic defect conferred by spo11-1 was confirmed by dyad analysis of spores derived from spo13-1 single-division meiosis in which recombination is not a requirement for viable ascospore production. Diploids homozygous for the spo13-1 mutation undergo meiotic levels of exchange followed by a single predominantly equational division and form asci containing two near-diploid spores. With the introduction of the spo11-1 mutation, high spore viability was retained, whereas intergenic recombination was reduced by more than 100-fold.