Open AccessThe yeast med1 mutant undergoes both meiotic homolog nondisjunction and precocious separation of sister chromatids.
Author(s) -
Beth Rockmill,
G. Shirleen Roeder
Publication year - 1994
Publication title -
genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.792
H-Index - 246
eISSN - 1943-2631
pISSN - 0016-6731
DOI - 10.1093/genetics/136.1.65
Subject(s) - nondisjunction , sister chromatids , genetics , biology , meiosis , establishment of sister chromatid cohesion , chromatid , mutant , chromosome segregation , synaptonemal complex , homologous chromosome , chromosomal crossover , homologous recombination , chromosome , aneuploidy , gene
A mutant at the yeast MED1 locus was isolated in a screen for sporulation-proficient, meiotic-lethal mutants. Synaptonemal complex formation in the med1 mutant is apparently normal and med1 strains undergo meiotic crossing over at approximately 50% of the wild-type level. The med1 mutant undergoes homolog nondisjunction at meiosis I, presumably as a consequence of the decrease in crossing over. In addition, the mutant undergoes precocious separation of sister chromatids, resulting in chromosome missegregation at both meiotic divisions. We suggest that the med1 mutation perturbs chromosome structure, leading to a reduction in recombination and a defect in sister chromatid cohesion.