Molecular polymorphism of ciliary proteins from different species of the ciliate Tetrahymena.

Ciliary proteins from five different Tetrahymena species were analyzed by means of SDS-polyacrylamide gel electrophoresis. Of at least 32 different polypeptides, only 2 were found to have identical molecular weights in all species. In any comparison of 2 species, a maximum of 60% and at least 20% of the proteins had indistinguishable molecular weights, depending on the combination examined. Extensive codominance of ciliary proteins was found in a F1 hybrid. No interspecific cross-reactions occurred in double-diffusion tests involving the cilia from different species and antisera produced against them in rabbits.