PREFERENTIAL OCCURRENCE OF NONSISTER SPORES IN TWO-SPORED ASCI OF SACCHAROMYCES CEREVISIAE: EVIDENCE FOR REGULATION OF SPORE-WALL FORMATION BY THE SPINDLE POLE BODY

Lance S. Davidow ¹, Loretta Goetsch ¹, and Breck Byers ¹

¹ Department of Genetics, SK-50, University of Washington, Seattle, Washington 98195

Yeast cells subjected to a reversible thermal arrest of meiosis yielded progressively fewer spores per ascus as the arrest was extended. Dissection of two-spored asci by a newly developed method that prevents selection of false asci revealed that the spores were not a random sample of the haploid meiotic products. Most, if not all, pairs of spores contain nonsister products of the reductional division. Electron microscopic examination of the meiotic cells revealed the cytological basis for this bias. All four spindle pole bodies (SPBs) present at the second meiotic division normally gain a structural modification (the outer plaque) upon which the initiation of the prospore wall occurs. In the formation of a two-spored ascus, only one spindle pole body on each meiosis II spindle was so modified. These observations suggest that the morphogenesis of spores is regulated at meiosis II by limiting the number of SPBs gaining the outer plaque. The enhancement of spore yield upon addition of fresh medium suggests that this morphogenetic regulation responds more directly to nutrient deprivation arising during the thermal arrest, rather than to elevated temperature per se.

This article has been cited by other articles:

				H.-C. Lo, L. Wan, A. Rosebrock, B. Futcher, and N. M. Hollingsworth Cdc7-Dbf4 Regulates NDT80 Transcription as Well as Reductional Segregation during Budding Yeast Meiosis Mol. Biol. Cell, November 1, 2008; 19(11): 4956 - 4967. [Abstract] [Full Text] [PDF]

				J. P. Gerke, C. T. L. Chen, and B. A. Cohen Natural Isolates of Saccharomyces cerevisiae Display Complex Genetic Variation in Sporulation Efficiency Genetics, October 1, 2006; 174(2): 985 - 997. [Abstract] [Full Text] [PDF]

				A. M. Neiman Ascospore Formation in the Yeast Saccharomyces cerevisiae Microbiol. Mol. Biol. Rev., December 1, 2005; 69(4): 565 - 584. [Abstract] [Full Text] [PDF]

				C. Taxis, P. Keller, Z. Kavagiou, L. J. Jensen, J. Colombelli, P. Bork, E. H.K. Stelzer, and M. Knop Spore number control and breeding in Saccharomyces cerevisiae: a key role for a self-organizing system J. Cell Biol., November 21, 2005; 171(4): 627 - 640. [Abstract] [Full Text] [PDF]

				C. G. Riedel, M. Mazza, P. Maier, R. Korner, and M. Knop Differential Requirement for Phospholipase D/Spo14 and Its Novel Interactor Sma1 for Regulation of Exocytotic Vesicle Fusion in Yeast Meiosis J. Biol. Chem., November 11, 2005; 280(45): 37846 - 37852. [Abstract] [Full Text] [PDF]

				M. E. Nickas, A. E. Diamond, M.-J. Yang, and A. M. Neiman Regulation of Spindle Pole Function by an Intermediary Metabolite Mol. Biol. Cell, June 1, 2004; 15(6): 2606 - 2616. [Abstract] [Full Text] [PDF]

				M. E. Nickas, C. Schwartz, and A. M. Neiman Ady4p and Spo74p Are Components of the Meiotic Spindle Pole Body That Promote Growth of the Prospore Membrane in Saccharomyces cerevisiae Eukaryot. Cell, June 1, 2003; 2(3): 431 - 445. [Abstract] [Full Text] [PDF]

				M. E. Nickas and A. M. Neiman Ady3p Links Spindle Pole Body Function to Spore Wall Synthesis in Saccharomyces cerevisiae Genetics, April 1, 2002; 160(4): 1439 - 1450. [Abstract] [Full Text] [PDF]

				C. Deng and W. S. Saunders ADY1, A Novel Gene Required for Prospore Membrane Formation at Selected Spindle Poles in Saccharomyces cerevisiae Mol. Biol. Cell, September 1, 2001; 12(9): 2646 - 2659. [Abstract] [Full Text] [PDF]

				B. K. Bajgier, M. Malzone, M. Nickas, and A. M. Neiman SPO21 Is Required for Meiosis-specific Modification of the Spindle Pole Body in Yeast Mol. Biol. Cell, June 1, 2001; 12(6): 1611 - 1621. [Abstract] [Full Text] [PDF]

				A. Wesp, S. Prinz, and G. R. Fink Conservative Duplication of Spindle Poles during Meiosis in Saccharomyces cerevisiae J. Bacteriol., April 1, 2001; 183(7): 2372 - 2375. [Abstract] [Full Text]

				X. Zeng and W. S. Saunders The Saccharomyces cerevisiae Centromere Protein Slk19p Is Required for Two Successive Divisions During Meiosis Genetics, June 1, 2000; 155(2): 577 - 587. [Abstract] [Full Text]

				H Friesen, R Lunz, S Doyle, and J Segall Mutation of the SPS1-encoded protein kinase of Saccharomyces cerevisiae leads to defects in transcription and morphology during spore formation. Genes & Dev., September 15, 1994; 8(18): 2162 - 2175. [Abstract] [PDF]

				L.R. Bell and B. Byers Homologous Association of Chromosomal DNA during Yeast Meiosis Cold Spring Harb Symp Quant Biol, January 1, 1983; 47(0): 829 - 840. [Abstract] [PDF]