Herman A I, Griffin P S
J Bacteriol. 1968 Aug;96(2):457-61. doi: 10.1128/jb.96.2.457-461.1968.
Six independent ultraviolet-induced respiratory-deficient mutants (petites) of Saccharomyces lactis were isolated and characterized. Two possessed a normal cytochrome spectrum, another displayed an increased level of all the cytochromes, and three suffered from a partial or complete loss of one or more of the cytochromes a, b, c, and c(1). All of the mutants were segregational petites; none was vegetative. Determination of linkage relationships between mutants was restricted because matings between mutants, homozygous or heterozygous, for loci affecting cytochrome content were blocked at various stages in the mating-sporulating sequence. At least three of the petites were genetically nonidentical. Three of the mutations appeared to occupy loci within the same linkage group; two of the three mutations that mapped within this region were cytochrome-deficient. Growth at high or low temperatures, under increased osmotic pressure or in media supplemented with various fatty acids or sterols, did not relieve the physiological defects in these mutants. Reasons for the differences in survival of segregational and vegetative petites within this species are examined.
分离并鉴定了乳酸酵母的六个独立的紫外线诱导呼吸缺陷型突变体（小菌落）。其中两个具有正常的细胞色素光谱，另一个所有细胞色素水平升高，还有三个细胞色素a、b、c和c1中的一种或多种部分或完全缺失。所有突变体都是分离型小菌落；没有一个是营养型的。由于影响细胞色素含量的位点的纯合或杂合突变体之间的交配在交配-孢子形成序列的不同阶段受阻，因此对突变体之间连锁关系的测定受到限制。至少有三个小菌落基因不同。其中三个突变似乎位于同一连锁群内的位点；定位在该区域内的三个突变中有两个是细胞色素缺陷型。在高温或低温、增加渗透压或添加各种脂肪酸或固醇的培养基中生长，并未缓解这些突变体的生理缺陷。研究了该物种内分离型和营养型小菌落生存差异的原因。
