THE GENETICS OF YEAST FLOCCULATION

Abstract

A short review of the development of yeast genetics in general, and with respect to flocculation in particular, is presented. At least three genes, two dominant and one recessive, confer flocculence, only one of these genes requiring to be present. The spontaneous gene mutation or mitotic segregation rates from flocculence to non-flocculence are high and are much higher than those rates in the reverse direction. Attempts were made to estimate the ploidy of some commercial strains of Saccharomyces cerevisiae by measurement of cell volume and DNA content.