Pratje E, Schulz R, Schnierer S, Michaelis G
Mol Gen Genet. 1979 Nov;176(3):411-5. doi: 10.1007/BF00333105.
The role of mitochondrial protein synthesis, electron transport, and four specific mitochondrial gene products on sporulation were studied in respiratory deficient mit- mutants. These mutants were isolated in an op 1 strain and localized on the mitochondrial genome by petite deletion mapping. All 153 mutations studied could be assigned to the four mitochondrial regions OXI1, OXI2, OXI3 and COB, known to affect cytochrome c oxidase and cytochrome b. The specific loss of one mitochondrially translated polypeptide was found in some mutants of each locus: OXI1--cytochrome c oxidase subunit 2, OXI2--subunit 3, OXI3--subunit 1, and COB--cytochrome b. The ability of diploid mit- mutants to sporulate was systematically investigated. About one third of the mutants, representing three loci, were incapable of forming spores. All other cultures produced either respiratory competent mit+ tetrads, both mit+ and mit- tetrads, or only mit- tetrads. Mutants forming mit- tetrads mapped in all four loci. These results demonstrate that in contrast to petite mutants some mit- mutants have retained the ability to perform meiosis and sporulation.
在呼吸缺陷型线粒体突变体中研究了线粒体蛋白质合成、电子传递以及四种特定线粒体基因产物在孢子形成过程中的作用。这些突变体是在一个op1菌株中分离得到的，并通过小缺失图谱定位在线粒体基因组上。所研究的153个突变都可归属于四个线粒体区域OXI1、OXI2、OXI3和COB，已知这些区域会影响细胞色素c氧化酶和细胞色素b。在每个位点的一些突变体中发现了一种线粒体翻译多肽的特异性缺失：OXI1——细胞色素c氧化酶亚基2，OXI2——亚基3，OXI3——亚基1，以及COB——细胞色素b。系统地研究了二倍体线粒体突变体的孢子形成能力。约三分之一代表三个位点的突变体无法形成孢子。所有其他培养物产生的要么是呼吸功能正常的线粒体野生型四分体，要么是线粒体野生型和突变型四分体，要么只有线粒体突变型四分体。形成线粒体突变型四分体的突变体分布在所有四个位点。这些结果表明，与小菌落突变体不同，一些线粒体突变体保留了进行减数分裂和孢子形成的能力。
