Genetics: The Mating Reaction, Mating Types, System of Breeding Relationships, and Inheritance in the Species of Paramecium

Abstract

With the discovery of the existence of mating types in sibling species of the P. aurelia complex by Sonneborn in 1937, the genetics of Paramecium and other ciliates entered a new phase. With this important fact in the hands of biologists, it now became possible to actually cross-breed stocks of diverse genetic ancestry just as in the higher multicellular animals. To date, Paramecium, Euplotes, and Tetrahymena have been extensively exploited. With the exception of Blepharisma (Miyake, 1974; Nanney, 1980), the great wealth of material in other ciliates is as yet untouched. The existence of mating types in other ciliates may demonstrate more effectively the answers to some of the problems in genetics, sexuality, and cytogenetics.