Is there selective mating in Tetrahymena during genomic exclusion?

Abstract

SYNOPSIS. Genomic exclusion is characterized by 2 rounds of mating. If exconjugants from different pairs remated at random after the first mating, we would expect a 1:2:1 ratio for genes present in heterozygous condition in the normal parent. An excess of homozygotes is observed which is similar for 2 different genes, suggesting that 10% of the rematings occur between exconjugants from the same Round 1 pair. Some but not all of these homozygotes can be attributed to a lack of separation of mates after the first round of mating. The rest may result because of differential mortality, induced autogamy or preferential remating.