title: Sgo1 is required for co-segregation of sister chromatids during achiasmate meiosis I.
abstract: The reduction of chromosome number during meiosis is achieved by two successive rounds of chromosome segregation, called meiosis I and meiosis II. While meiosis II is similar to mitosis in that sister kinetochores are bi-oriented and segregate to opposite poles, recombined homologous chromosomes segregate during the first meiotic division. Formation of chiasmata, mono-orientation of sister kinetochores and protection of centromeric cohesion are three major features of meiosis I chromosomes which ensure the reductional nature of chromosome segregation. Here we show that sister chromatids frequently segregate to opposite poles during meiosis I in fission yeast cells that lack both chiasmata and the protector of centromeric cohesion Sgo1. Our data are consistent with the notion that sister kinetochores are frequently bi-oriented in the absence of chiasmata and that Sgo1 prevents equational segregation of sister chromatids during achiasmate meiosis I.
authors.affiliation: Department of Chromosome Biology, Max F. Perutz Laboratories, University of Vienna, Austria.
authors.forename: Andrej
authors.initials: A
authors.lastname: Dudas
authors.forename: Shazia
authors.initials: S
authors.lastname: Ahmad
authors.forename: Juraj
authors.initials: J
authors.lastname: Gregan
mesh_terms: D002842:Chromatids / Q000378:metabolism*; D020090:Chromosome Segregation; D018386:Kinetochores / Q000378:metabolism; D008540:Meiosis; D009687:Nuclear Proteins / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*
chemical_list: D009687:Nuclear Proteins; D029701:Saccharomyces cerevisiae Proteins; C482640:Sgo1 protein, S cerevisiae