Separation of roles of Zip1 in meiosis revealed in heterozygous mutants of Saccharomyces cerevisiae.
Synapsis of homologs during meiotic prophase I is associated with a protein complex built along the bivalents--the synaptonemal complex (SC). Mutations in the SC-component gene ZIP1 diminish SC formation, leading to reduced recombination levels and low spore viability. Here we show that in SK1 strains heterozygous for a deletion of ZIP1 in certain regions meiotic interference are impaired with no decrease in recombination levels. The extent of synapsis is over all reduced and NDJ levels of a large endogenous chromosome and of artificial chromosomes (YACs) rise to twice the level of wild type strains. A substantial proportion of mis-segregating YACs had undergone crossing over. This demonstrates that different functions of Zip1 display differential sensitivities to changes in expression levels.
Klutstein
Michael
M
Department of Genetics, The Hebrew University, 91904, Jerusalem, Israel. Michael.Klutstein@cancer.org.uk
Xaver
Martin
M
Shemesh
Ronen
R
Zenvirth
Drora
D
Klein
Franz
F
Simchen
Giora
G
D023902:Chromosome Pairing / Q000235:genetics; D020090:Chromosome Segregation / Q000235:genetics; D018244:Chromosomes, Artificial, Yeast / Q000235:genetics; D015825:Chromosomes, Fungal / Q000235:genetics; D004247:DNA / Q000235:genetics; D017353:Gene Deletion; D006238:Haploidy; D006579:Heterozygote; D006801:Humans; D008540:Meiosis / Q000235:genetics*; D009154:Mutation / Q000235:genetics*; D009630:Nondisjunction, Genetic; D009687:Nuclear Proteins / Q000378:metabolism*; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D013172:Spores, Fungal / Q000235:genetics
D009687:Nuclear Proteins; D029701:Saccharomyces cerevisiae Proteins; C090118:Zip1 protein, S cerevisiae; D004247:DNA