K. Vanwinkleswift et al., THE CHLAMYDOMONAS ZYGOSPORE - MUTANT STRAINS OF CHLAMYDOMONAS-MONOICABLOCKED IN ZYGOSPORE MORPHOGENESIS COMPRISE 46 COMPLEMENTATION GROUPS, Genetics, 148(1), 1998, pp. 131-137
Chlamydomonas monoica undergoes homothallic sexual reproduction in res
ponse to nitrogen starvation. Mating pairs are established in clonal c
ulture via flagellar agglutination and fuse by way of activated mating
structures to form the quadriflagellate zygote. The zygote further ma
tures into a dormant diploid zygote spore through a series of events t
hat we collectively refer to as zygosporulation. Mutants that arrest d
evelopment prior to the completion of zygosporulation hare been obtain
ed through the use of a variety of mutagens, including ultraviolet irr
adiation, 5-fluorodeoxyuridine, ethyl methanesulfonate, and methyl met
hanesulfonate. Complementation analysis indicates that the present mut
ant collection includes alleles affecting 46 distinct zygote-specific
functions. The frequency with which alleles at previously defined loci
hare been recovered in the most recent mutant searches suggests that
as many as 30 additional zygote-specific loci may still remain to be i
dentified. Nevertheless, the present collection should provide a power
ful base for ultrastructural, biochemical, and molecular analysis of z
ygospore morphogenesis and dormancy in Chlamydomonas.