A selection procedure for obtaining conditional gametogenic mutants using a photosynthetically incompetent strain of Chlamydomonas reinhardi.

A new selection procedure has beed developed for the isolation of temperature sensitive gametogenic mutants in Chlamydomonas reinhardi. This technique makes use of pet-10-1, a mutant strain incapable of photosynthetic electron transport, and the redox dye, methyl viologen. Two mutants found by this method are discussed. The first, gam-4, does not agglutinate at 35 degrees, whereas the second, gam-5, is capable of sexual agglutination, but not of zygote formation at the restrictive temperature. Both mutants appear to be inherited in a Mendelian fashion and are expressed in mating type (+) and mating type (-).