Analysis of the kar3 meiotic arrest in Saccharomyces cerevisiae.
The motor protein Kar3p and its associated protein Cik1p are essential for passage through meiosis I. In the absence of either protein, meiotic cells arrest in prophase I. Experiments were performed to determine whether the arrest was caused by a structural inability to proceed through meiosis, or by a regulatory mechanism. The data demonstrate that the meiotic arrest is not structural; kar3 and cik1 mutants are able to form normal looking bipolar spindles and divide their DNA into two masses in spo11 mutant backgrounds. To identify the regulatory system necessary for the kar3/cik1 meiotic arrest, we tested whether the arrest could be bypassed by eliminating the pachytene checkpoint or the spindle checkpoint. The arrest is not solely dependent upon the pachytene checkpoint that monitors recombination and aspects of chromosome synapsis. Elimination of the spindle checkpoint failed to allow kar3 mutants to undergo meiosis I nuclear division, but phenotypes of the kar3/spindle checkpoint double mutants suggest that the kar3 meiotic arrest may be mediated by the spindle checkpoint.
Shanks
Robert M Q
RM
Department of Microbiology and Immunology, Dartmouth Medical School, Hanover, New Hampshire, USA.
Bascom-Slack
Carol
C
Dawson
Dean S
DS
D004706:Endodeoxyribonucleases; D004950:Esterases / Q000235:genetics; D008540:Meiosis; D008868:Microtubule Proteins / Q000172:deficiency / Q000235:genetics; D008869:Microtubule-Associated Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D049471:Pachytene Stage; D010641:Phenotype; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D008941:Spindle Apparatus / Q000378:metabolism; D000099257:Meiotic Recombination Protein SPO11
D004706:Endodeoxyribonucleases; D004950:Esterases; D008868:Microtubule Proteins; D008869:Microtubule-Associated Proteins; D029701:Saccharomyces cerevisiae Proteins; D000099257:Meiotic Recombination Protein SPO11; C076025:CIK1 protein, S cerevisiae; C063504:KAR3 protein, S cerevisiae; C097192:SPO13 protein, S cerevisiae