Shimoda C, Hirata A, Kishida M, Hashida T, Tanaka K
Mol Gen Genet. 1985;200(2):252-7. doi: 10.1007/BF00425432.
Meiosis-deficient mutants of the fission yeast Schizosaccharomyces pombe carrying mei1, mei2, mei3, mei4 and mes1 mutant alleles were characterized by electron microscopy and staining of the nucleus with 4', 6-diamidino-2-phenylindole. Zygotes of either mei1, mei2 or mei3 mutants contained one round nucleus with a single spindle pole body (SPB). These mutants were arrested before premeiotic DNA synthesis. Zygotes of mei4 mutants had one elongated nucleus containing thick electron-dense filaments (linear elements). In the mes1 mutant, the first meiotic division was completed but the SBPs did not duplicate. Modification of the SPB (outer plaque formation) was also blocked and the forespore membrane was not assembled. By haploidization, random spore and tetrad analyses, four essential genes for meiosis (mei2, mei3, mei4 and mes1) were mapped. Gene mei2 was located on chromosome I 14.2 cM distant from ura2. Gene mei3 was linked to ade7 (45.4 cM) on chromosome II. Gene mei4 was linked to cdc2 (0.6 cM) on chromosome II. Gene mes1 was linked to ura3 (25.3 cM) on chromosome I.
通过电子显微镜和用4',6-二脒基-2-苯基吲哚对细胞核进行染色，对携带mei1、mei2、mei3、mei4和mes1突变等位基因的粟酒裂殖酵母减数分裂缺陷型突变体进行了表征。mei1、mei2或mei3突变体的合子含有一个带有单个纺锤体极体（SPB）的圆形细胞核。这些突变体在减数分裂前DNA合成之前就被阻断。mei4突变体的合子有一个细长的细胞核，其中含有粗的电子致密丝（线性元件）。在mes1突变体中，第一次减数分裂完成，但SPB没有复制。SPB的修饰（外斑形成）也被阻断，前孢子膜没有组装。通过单倍体化、随机孢子和四分体分析，对减数分裂的四个必需基因（mei2、mei3、mei4和mes1）进行了定位。基因mei2位于第一条染色体上，距离ura2有14.2厘摩。基因mei3与第二条染色体上的ade7连锁（45.4厘摩）。基因mei4与第二条染色体上的cdc2连锁（0.6厘摩）。基因mes1与第一条染色体上的ura3连锁（25.3厘摩）。
