GSBS Student Publications


Meiosis in Saccharomyces cerevisiae mutants lacking the centromere-binding protein CP1

UMMS Affiliation

Graduate School of Biomedical Sciences; Department of Molecular Genetics and Microbiology



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Medical Subject Headings

Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; Chromosomes, Fungal; DNA-Binding Proteins; Fungal Proteins; Genes, Fungal; Meiosis; Mitosis; Plasmids; Saccharomyces cerevisiae; *Saccharomyces cerevisiae Proteins; Spores, Fungal


Life Sciences | Medicine and Health Sciences


CP1 (encoded by the CEP1 gene) is a centromere binding protein of Saccharomyces cerevisiae that binds to the conserved DNA element I (CDEI) of yeast centromeres. To investigate the function of CP1 in yeast meiosis, we analyzed the meiotic segregation of CEN plasmids, nonessential chromosome fragments (CFs) and chromosomes in cep1 null mutants. Plasmids and CFs missegregated in 10-20% of meioses with the most frequent type of aberrant event being precocious sister segregation at the first meiotic division; paired and unpaired CFs behaved similarly. An unpaired chromosome I homolog (2N + 1) also missegregated at high frequency in the cep1 mutant (7.6%); however, missegregation of other chromosomes was not detected by tetrad analysis. Spore viability of cep1 tetrads was significantly reduced, and the pattern of spore death was nonrandom. The inviability could not be explained solely by chromosome missegregation and is probably a pleiotropic effect of cep1. Mitotic chromosome loss in cep1 strains was also analyzed. Both simple loss (1:0 segregation) and nondisjunction (2:0 segregation) were increased, but the majority of loss events resulted from nondisjunction. We interpret the results to suggest that CP1 generally promotes chromatid-kinetochore adhesion.

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Citation: Genetics. 1992 May;131(1):43-53.

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