Fifty years of research on serotypes and mating types in Dileptus anser: A review.

The ciliate Dileptus anser is increasingly used as a laboratory model not only in protozoological research sensu stricto, but also in general biology. However, genetic studies of this ciliate have never been carried out, and this species is new to the comparative genetics of ciliates. This review describes the genetic experiments conducted at the Institute of Cytology of the Russian Academy of Sciences for the last 50 years. Two characters that are classical for the genetics of ciliates, serotypes and mating types were selected for analysis. The results presented do not fit into conventional genetic schemes and may have epigenetic nature. Features of this model that were revealed earlier (the simplest possible system of multiple mating types, full serial dominance of the alleles in the mat locus, the excretion of pheromones, etc.) are promising with regard to interesting comparisons of breeding systems in ciliates. The results obtained in studies of mating pheromones in D. anser have demonstrated that this model is a perspective one for further exploration of intercellular recognition in lower eukaryotes and of other related issues.