A mutant of Saccharomyces cerevisiae that exhibits multiple isoacceptors for several of its transfer RNAs.

Summary A strain of Saccharomyces cerevisiae, known to produce multiple isoaccepting forms of several tRNA's which differ from a standard wild type strain, has been studied genetically. The multiple isoaccepting tRNA phenotype behaves as if it is caused by a single recessive mutation. Five tetrads were analyzed and all showed a 2:2 segregation of mutant to wild type profiles for Phe-tRNA^Phe. Furthermore, the multiple isoacceptors for the other tRNA's in the mutant strain are probably caused by the same mutation, since Tyr-tRNA^Tyr and Val-tRNA^Val also exhibit 2:2 segregation for mutant versus wild type tRNA profiles and the segregation pattern is the same as that for Phe-tRNA^Phe.