Serotypes of the lower ciliate Dileptus anser

The author's data on the serotype composition in various clones of Dileptus anser are reviewed. This species is a novel subject of choice for studying the serotype problem in ciliates. The results obtained for serotypes of D. anser demonstrated several features shared also by some higher ciliates of the genera Paramecium and Tetrahymena, i.e. the well known classical models for serotype research. At the same time, some particular data obtained for D. anser do not fit in with the generally accepted picture of relevant events. Special attention is paid to a poor knowledge of the sexual process in this ciliate, which obviously hampers the true understanding of many events. Nevertheless, D. anser may be regarded as a suitable model for studying such important problems of general biology as epigenetic variability or inheritance.