Genic determination of the autogamy trait in the hypotrich ciliate,Euplotes crassus

Abstract

SUMMARYCross-fertilizing stocks ofEuplotes crassus, differing as to the ability to undergo autogamy, were subjected to breeding analysis. The resulting data are consistent with the interpretation that a single locus (a) with a pair of alleles (a+;a−) controls the ability to undergo autogamy. The two alleles express a simple dominance relationship in which the dominant allele (a+) permits expression of the autogamy trait. Cross-breeding experiments also suggest that thealocus is not linked to themtlocus which determines the mating-type trait.