Open AccessCytoduction in Chlamydomonas reinhardtii.
Author(s) -
René-Fernand Matagne,
Claire Remacle,
Monique Dinant
Publication year - 1991
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.88.16.7447
Subject(s) - zygote , biology , ploidy , chlamydomonas reinhardtii , meiosis , chlamydomonas , genetics , mitosis , mating type , cytokinesis , chloroplast dna , mating , microbiology and biotechnology , polyploid , chloroplast , cell division , gene , mutant , cell , embryogenesis
After conjugation between Chlamydomonas gametes of opposite mating type, a transient dikaryon is formed. The two nuclei fuse within 4-6 hr after mating. The young diploid zygote differentiates into dormant zygospore competent to complete meiosis, or more rarely (2-10% of cases) it undergoes mitosis to produce a stable diploid progeny. We here bring genetical, biochemical, and cytological evidence that among the mitotic zygotes, a large proportion of them undergo cytokinesis without fusion of the nuclei-a process that has been termed "cytoduction." By using appropriate genetic markers, haploid cytoductants that possess the nuclear genotype of one parent and the chloroplast marker of the other parent can easily be isolated. Genetical analysis and hybridization experiments moreover show that many haploid cytoductants transmit the chloroplast DNA molecules of both parents and that, as in diploids, these DNA copies occasionally recombine. This process of cytoduction extends the life cycle of Chlamydomonas and provides new tools for its genetic analysis.