Zolan M E, Tremel C J, Pukkila P J
Department of Natural Sciences, University of Michigan-Dearborn 48128.
Genetics. 1988 Oct;120(2):379-87. doi: 10.1093/genetics/120.2.379.
We have isolated four gamma-ray-sensitive mutants of the basidiomycete Coprinus cinereus. When homozygous, two of these (rad 3-1 and rad 9-1) produce fruiting bodies with very few viable basidiospores, the products of meiosis in this organism. A less radiation-sensitive allele of RAD 3, rad 3-2, causes no apparent meiotic defect in homozygous strains. Quantitative measurements of oidial survival of rad 3-1; rad 9-1 double mutants compared to the single mutants indicated that rad 3-1 and rad 9-1 mutants are defective in the same DNA repair pathway. In the few viable basidiospores that are produced by these two strains, essentially normal levels of meiotic recombination can be detected. None of the mutants exhibits increased sensitivity to UV radiation. Cytological examination of meiotic chromosomes from mutant and wild-type fruiting bodies showed that rad 3-1 homozygous strains fail to condense and pair homologous chromosomes during prophase I. Although rad 9-1 strains are successful at chromosome pairing, meiosis is usually not completed in these mutants.
我们已经分离出了担子菌灰盖鬼伞的四个对γ射线敏感的突变体。当这些突变体纯合时，其中两个（rad 3-1和rad 9-1）产生的子实体中 viable 担孢子极少，担孢子是该生物体减数分裂的产物。RAD 3的一个对辐射敏感性较低的等位基因rad 3-2，在纯合菌株中不会导致明显的减数分裂缺陷。与单突变体相比，对rad 3-1；rad 9-1双突变体的粉孢子存活情况进行定量测量表明，rad 3-1和rad 9-1突变体在相同的DNA修复途径中存在缺陷。在这两个菌株产生的少数 viable 担孢子中，可以检测到基本正常水平的减数分裂重组。没有一个突变体对紫外线辐射表现出更高的敏感性。对突变体和野生型子实体减数分裂染色体的细胞学检查表明，rad 3-1纯合菌株在减数分裂前期I无法使同源染色体浓缩和配对。虽然rad 9-1菌株在染色体配对方面成功，但这些突变体中的减数分裂通常无法完成。 （注：原文中“viable”在中文里没有完全对应的简洁词汇，这里暂保留英文，你可根据实际情况调整为更合适的表述，比如“可育的”等）
