Schroeder R, Breitenbach M
J Bacteriol. 1981 May;146(2):775-83. doi: 10.1128/jb.146.2.775-783.1981.
We investigated the sporulation properties of a series of diploid Saccharomyces cerevisiae strains homozygous for inositol auxotrophic markers. The strains required different amounts of inositol for the completion of sporulation. Shift experiments revealed two phases of inositol requirement during sporulation which coincided with the two phases of lipid synthesis found by earlier workers. Phase I was at the beginning and during premeiotic deoxyribonucleic acid synthesis; phase II immediately preceded the appearance of mature asci. Of the inositol taken up by sporulating cells, 90% was incorporated into inositol phospholipids. By two-dimensional thin-layer chromatography, eight compounds were resolved, one of which was sporulation specific. The majority of the inositol phospholipids were, however, identical to those found in vegetatively growing cells. In the absence of inositol, the cells did not sporulate but, after a certain time, were unable to return to vegetative growth. These nonsporulating cells did, however, incorporate acetate into lipids and double their deoxyribonucleic acid content in the premeiotic phase. We believe that it is this lack of coordination of biosynthetic events which causes inositol-less death on sporulation media without inositol.
我们研究了一系列对肌醇营养缺陷型标记纯合的二倍体酿酒酵母菌株的孢子形成特性。这些菌株完成孢子形成所需的肌醇量不同。转移实验揭示了孢子形成过程中肌醇需求的两个阶段，这与早期研究人员发现的脂质合成的两个阶段相吻合。第一阶段在减数分裂前的脱氧核糖核酸合成开始时及进行过程中；第二阶段紧接在成熟子囊出现之前。在进行孢子形成的细胞摄取的肌醇中，90%被掺入肌醇磷脂中。通过二维薄层色谱法，分离出了8种化合物，其中一种是孢子形成特异性的。然而，大多数肌醇磷脂与在营养生长细胞中发现的相同。在没有肌醇的情况下，细胞不会形成孢子，但在一段时间后，无法恢复营养生长。然而，这些不形成孢子的细胞在减数分裂前阶段确实将乙酸盐掺入脂质中，并使其脱氧核糖核酸含量加倍。我们认为，正是这种生物合成事件的缺乏协调导致在没有肌醇的孢子形成培养基上因缺乏肌醇而死亡。
