AN ENDOMITOTIC EFFECT OF A CELL CYCLE MUTATION OF SACCHAROMYCES CEREVISIAE

David Schild ¹, Honnavara N. Ananthaswamy ², and Robert K. Mortimer ³

¹ Department of Biophysics, University of California, Berkeley, California 94720
² Department of Medical Physics, University of California, Berkeley, California 94720
³ Department of Donner Laboratory, University of California, Berkeley, California 94720

A recessive temperature-sensitive mutation of Saccharomyces cerevisiae has been isolated and shown to cause an increase in ploidy in both haploids and diploids. Genetic analysis revealed that the strain carrying the mutation was an aa diploid, although MNNG mutagenesis had been done on an a haploid strain. When the mutant strain was crossed with an diploid and the resultant tetraploid sporulated, some of the meiotic progeny of this tetraploid were themselves tetraploid, as shown by both genetic analysis and DNA measurements, instead of diploid as expected of tetraploid meiosis. The ability of these tetraploids to continue to produce tetraploid meiotic progeny was followed for four generations. Homothallism was excluded as a cause of the increase in ploidy; visual pedigree analysis of spore clones to about the 32-cell stage failed to reveal any zygotes, and haploids that diploidized retained their mating type. An extra round of meiotic DNA synthesis was also considered and excluded. It was found that tetraploidization was independent of sporulation temperature, but was dependent on the temperature of germination and the growth of the spores. Increase in ploidy occurred when the spores were germinated and grown at 30°, but did not occur at 23°. Two cycles of sporulation and growth at 23° resulted in haploids, which were shown to diploidize within 24 hr when grown at 30°. Visual observation of the haploid cells incubated at 36° revealed a cell-division-cycle phenotype characteristic of mutations that affect nuclear division; complementation analysis demonstrated that the mutation, cdc31–2, is allelic to cdc31–1, a mutation isolated by Hartwell et al. (1973) and characterized as causing a temperature-sensitive arrest during late nuclear division. The segregation of cdc31–2 in heterozygous diploids was 2:2 and characteristic of a noncentromere-linked gene.

This article has been cited by other articles:

				H. Kanta, L. Laprade, A. Almutairi, and I. Pinto Suppressor Analysis of a Histone Defect Identifies a New Function for the Hda1 Complex in Chromosome Segregation Genetics, May 1, 2006; 173(1): 435 - 450. [Abstract] [Full Text] [PDF]

				A. Paoletti, N. Bordes, R. Haddad, C. L. Schwartz, F. Chang, and M. Bornens Fission Yeast cdc31p Is a Component of the Half-bridge and Controls SPB Duplication Mol. Biol. Cell, July 1, 2003; 14(7): 2793 - 2808. [Abstract] [Full Text] [PDF]

				S. L. Jaspersen, T. H. Giddings Jr., and M. Winey Mps3p is a novel component of the yeast spindle pole body that interacts with the yeast centrin homologue Cdc31p J. Cell Biol., December 23, 2002; 159(6): 945 - 956. [Abstract] [Full Text] [PDF]

				W. Khalfan, I. Ivanovska, and M. D. Rose Functional Interaction Between the PKC1 Pathway and CDC31 Network of SPB Duplication Genes Genetics, August 1, 2000; 155(4): 1543 - 1559. [Abstract] [Full Text]

				M. d. l. C. Muñoz-Centeno, S. McBratney, A. Monterrosa, B. Byers, C. Mann, and M. Winey Saccharomyces cerevisiae MPS2 Encodes a Membrane Protein Localized at the Spindle Pole Body and the Nuclear Envelope Mol. Biol. Cell, July 1, 1999; 10(7): 2393 - 2406. [Abstract] [Full Text]

				M. K. Shirra and K. M. Arndt Evidence for the Involvement of the Glc7-Reg1 Phosphatase and the Snf1-Snf4 Kinase in the Regulation of INO1 Transcription in Saccharomyces cerevisiae Genetics, May 1, 1999; 152(1): 73 - 87. [Abstract] [Full Text]

				D. S. Sullivan, S. Biggins, and M. D. Rose The Yeast Centrin, Cdc31p, and the Interacting Protein Kinase, Kic1p, Are Required for Cell Integrity J. Cell Biol., November 2, 1998; 143(3): 751 - 765. [Abstract] [Full Text] [PDF]

				F. C. Luca and M. Winey MOB1, an Essential Yeast Gene Required for Completion of Mitosis and Maintenance of Ploidy Mol. Biol. Cell, January 1, 1998; 9(1): 29 - 46. [Abstract] [Full Text]

				S. Middendorp, A. Paoletti, E. Schiebel, and M. Bornens Identification of a new mammalian centrin gene, more closely related to Saccharomyces cerevisiae CDC31 gene PNAS, August 19, 1997; 94(17): 9141 - 9146. [Abstract] [Full Text] [PDF]

				G Pereira and E Schiebel Centrosome-microtubule nucleation J. Cell Sci., January 2, 1997; 110(3): 295 - 300. [Abstract] [PDF]

				A Paoletti, M Moudjou, M Paintrand, J. Salisbury, and M Bornens Most of centrin in animal cells is not centrosome-associated and centrosomal centrin is confined to the distal lumen of centrioles J. Cell Sci., January 12, 1996; 109(13): 3089 - 3102. [Abstract] [PDF]