Increased ploidy and KAR3 and SIR3 disruption alter the dynamics of meiotic chromosomes and telomeres
| Autor: | Josef Loidl, Harry Scherthan, Edgar Trelles-Sticken |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Saccharomyces cerevisiae Proteins
Haploidisation Centromere Cell Cycle Proteins Saccharomyces cerevisiae Haploidy Biology Prophase Meiosis Polyploid Meiotic telomere clustering Silent Information Regulator Proteins Saccharomyces cerevisiae Gametogenesis Genetics Ploidies Centromere clustering fungi Nuclear Proteins Cell Biology Telomere Diploidy Chromosome Pairing Germ Cells Mating of yeast Ploidy Microtubule-Associated Proteins |
| Zdroj: | Journal of Cell Science. 116:2431-2442 |
| ISSN: | 1477-9137 0021-9533 |
| DOI: | 10.1242/jcs.00453 |
| Popis: | We investigated the sequence of chromosomal events during meiotic prophase in haploid, diploid and autotetraploid SK1 strains of Saccharomyces cerevisiae. Using molecular cytology, we found that meiosis-specific nuclear topology (i.e. dissolution of centromere clustering, bouquet formation and meiotic divisions) are significantly delayed in polyploid SK1 meiosis. Thus, and in contrast to the situation in plants, an increase in ploidy extends prophase I in budding yeast. Moreover, we found that bouquet formation also occurs in haploid and diploid SK1 meiosis deficient in the telomeric heterochromatin protein Sir3p. Diploid sir3Delta SK1 meiosis showed pleiotropic defects such as delayed centromere cluster resolution in a proportion of cells and impeded downstream events (i.e. bouquet formation, homologue pairing and meiotic divisions). Meiotic telomere clustering occurred in diploid and haploid sir3Delta strains. Using the haploid system, we further show that a bouquet forms at the kar3Delta SPB. Comparison of the expression of meiosis-specific Ndj1p-HA and Zip1p in haploid control and kar3Delta time courses revealed that fewer cells enter the meiotic cycle in absence of Kar3p. Elevated frequencies of bouquets in kar3Delta haploid meiosis suggest a role for Kar3p in regulation of telomere dynamics. |
| Databáze: | OpenAIRE |
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