Mating reaction in Saccharomyces cerevisiae

Abstract

A diffusible sex-specific substance called α substance-I (αS-I) was isolated from culture filtrate of α type strains of the yeast Saccharomyces cerevisiae. The isolated αS-I, an oligopeptide, induced sexual cell agglutinability in inducible a type strains and enhanced the agglutinability in constitutive a type strains. The induction of sexual agglutinability was detected in 30 min and reached maximum in 90 min, when 0.2 μg/ml of αS-I was added to inducible a type cells. The a type-specific factor responsible for sexual cell agglutination, called a type agglutination factor (aAF), was shown to be produced during the induction or the enhancement of agglutinability of a type cells by αS-I. The aAF produced in response to αS-I was not different in the susceptibility to proteolytic enzymes and disulfide-cleaving agents from those produced constitutively in the absence of αS-I.