A mating type-linked gene cluster expressed in Chlamydomonas zygotes participates in the uniparental inheritance of the chloroplast genome.
A characteristic feature of early zygote development in Chlamydomonas is the selective degradation of chloroplast DNA from the mating type minus parent. The zygote-specific gene cluster ezy-1 is linked to the mating type locus and is transcribed almost immediately upon zygote formation. We show here that the acidic Ezy-1 polypeptide is rapidly transported to both the plus and minus chloroplasts, where it interacts with each chloroplast nucleoid. Expression of ezy-1 is selectively inhibited when plus, but not minus, gametes are briefly ultraviolet irradiated just prior to mating, a treatment known to disrupt the uniparental inheritance of chloroplast traits. We propose that the Ezy-1 polypeptide participates in the destruction of the minus chloroplast DNA in zygotes and thus the uniparental inheritance of chloroplast traits. The ezy-1 gene represents a valuable molecular probe for dissecting mechanisms underlying organelle inheritance.
Armbrust
E V
EV
Department of Biology, Washington University, St. Louis, Missouri 63130.
Ferris
P J
PJ
Goodenough
U W
UW
D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D016825:Chlamydomonas reinhardtii / Q000235:genetics* / Q000502:physiology; D002736:Chloroplasts / Q000502:physiology*; D003001:Cloning, Molecular; D003433:Crosses, Genetic; D005800:Genes, Fungal; D049770:Genes, Mating Type, Fungal; D008969:Molecular Sequence Data; D005810:Multigene Family; D015800:Protozoan Proteins / Q000096:biosynthesis / Q000235:genetics*; D015183:Restriction Mapping; D015053:Zygote / Q000502:physiology*
D015800:Protozoan Proteins