摘要
本文通过四分子分析将酿酒酵母中另一控制渗透敏感的基因osm3进行了定位。遗传分析表明,osm3是位于染色体Ⅱ上的1个新基因,与gal1座位相距大约45厘摩。其第二次分裂分离频率为51.01%,它与着丝粒的图距为25.51厘摩,属着丝粒连锁基因。回复突变的研究结果表明,渗透敏感性状很可能是因为osm3座位上发生了错义或无义突变所致。 根据渗透敏感菌株和正常菌株对高渗透压反应试验,证明了高的胞内甘油含量是酵母在高渗条件下生长所必需的。osm3菌株不能耐高渗的主要原因是由于甘油转运失调所致,OSM3基因产物可能与甘油的转运过程有关。本文还就高渗对酿酒酵母发酵力的影响进行了讨论。
recessive nuclear gene mutation of Sacchromyccs cerevisiae, osm3, which causes growth inhibition on hypertonic media, has been mapped on the chromosome Ⅱ by tetrad analysis. Its second-division segregation frequency is about 51.01%, and the map distances between osm3 and the centromere of chromosome Ⅱ is about 25.51 centimorgans and it is approximately 45 centimorgans far gene gall. The studies on the reverse mutation of osm3 indicated that this osmotic-sensitivity arises from a missense or nonsense mutation in OSM3 locus.The response of yeast to osmotic stress and the mechanism of osm3 gene function were investigated. The results indicated that high intracellular glycerol content is necessary for yeast to grow in hypertonic media; The gene product of osm3 is probably relative to the process of glycerol transportation. Finally, the effect of osmotic stress on fermentability was also discussed.
基金
国家自然科学基金~~
关键词
酿酒酵母
渗透敏感基因
基因定位
Saccharomyces cerevisiae. Osmotic-sensitive Gene osm3, Gene Mapping, Reverse mutation, Glycerol transportation
