title: Mutations that alter the transmission of chloroplast genes in Chlamydomonas.
abstract: Two mutations are described that alter the pattern of inheritance of chloroplast genes in Chlamydomonas. The mutant gene mat-1 linked to the mating type allele mt(-) greatly increases the frequency of exceptional zygotes, i.e., zygotes that transmit chloroplast genes from the mt(-) (male) parent. In some crosses, 80-90% of the zygotes are biparental, transmitting chloroplast genes from both parents. The mat-2 mutation, linked to mt(+), acts to decrease the frequency of exceptional zygotes below the spontaneous level. The mutant effects are discussed in terms of a DNA modification-restriction system, postulated to regulate the transmission of chloroplast DNA in zygotes.
mesh_terms: D002467:Cell Nucleus; D002696:Chlamydomonas / Q000648:ultrastructure; D002736:Chloroplasts; D003227:Conjugation, Genetic; D003433:Crosses, Genetic; D004247:DNA; D008040:Genetic Linkage; D005838:Genotype; D009154:Mutation / Q000528:radiation effects; D010641:Phenotype; D011831:Radiation Genetics; D014466:Ultraviolet Rays
chemical_list: D004247:DNA