An extensive behavioural and genetic analysis of the Pawn mutants inParamecium aurelia

Abstract

SUMMARY: Pawns are behavioural mutants which show impairment in membrane excitability and are, therefore, devoid of normal avoiding reactions. We obtained 103 lines of Pawns through mutagenesis and screening. Among those that yielded to breeding studies, 59 lines belonged to thepwAcomplementation group and 38 lines belonged to thepwBgroup. No other genic loci were found in this extensive analysis. Mutants of thepwAlocus showed various degrees of phenotypic leakiness. Based on the pheno- and genotypic differences, we estimated that at least 45 independent mutational events were represented in these 103 Pawn lines.