ALLELISM OF PLEIOTROPIC DRUG RESISTANCE INSACCHAROMYCES CEREVISIAE

Abstract

Allelism of pleiotropic drug resistant (pdr) mutants was evaluated by complementation tests, linkage to chromosome-VII centromere markers and response to a partial suppressor (sur). Complementation tests were confounded by incomplete dominance and somatic segregation. Phenotypic suppression by sur was observed for all mutant and wild type alleles and thus could not be used to distinguish alleles. Five different alleles were tentatively identified by their close linkage to leu1; 88 tetrads from 3 factor crosses produced the following linkages: leu1 (4.7), pdr1 (17.0), trp5. Resistance of DRI 9/T7, a [cir o] strain of French origin, was not inherited as an allele of pdr but was controlled by a different pleiotropic centromere linked gene. An evaluation of published data suggest that ant1, AMY1, til1, cyh3, BOR2 and axe1 may be alleles of pdr. Thus pdr apparently is an allele that influences permeability to many inhibitors.