Meiosis cerevisiae

Fig. 2.6 The moqjhological events of sporulation in Saccharomyces cerevisiae. (a) starved cell V, vacuole LG, lipid granule ER, endoplasmic reticulum CW, cell wall M, mitochondrion S, spindle pole SM, spindle microtubules N, nucleus NO, nucleolus, (b) Synaptonemal complex (SX) and development of polycomplex body (PB) along with division of spindle pole body in (c). (d) First meiotic division which is completed in (e). (f) Prepararation for meiosis II. (g) Enlargement of prospore wall, culminating in enclosure of separate haploid nuclei (h). (i) Spore coat (SC) materials produced and deposited, giving rise to the distinct outer spore coat (OSC) seen in the completed spores of the mature ascus (j). Reproduced from the review by Dickinson (1988) with permission from Blackwell Science Ltd.

Grandin, N., and Reed, S. I. (1993). Differential function and expression of Saccharomy-ces cerevisiae B-type cyclins in mitosis and meiosis. Mol. Cell. Biol. 13 2113— 2125. 

Sherman, A., M. Shefer, S. Sagee, and Y. Kassir, Post-transcriptional regulation of IME1 determines initiation of meiosis in Saccharomyces cerevisiae. Mol. Gen. Genet. 237 375-384, 1993. 

Most of the information concerning recombination between repeated sequences has been derived from studies in the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe,5 although some classes of ectopic recombination have also been studied in mammalian cells.6 The yeast studies indicate that the rates of ectopic recombination are surprisingly high (similar to the rates of classical recombination) and that the rates of these events are much higher in meiosis than in mitosis. Conversion events involving repeats on nonhomologous chromosomes are associated... 

Since the cofactors are not essential in S. cerevisiae, but the tubulin heterodimer is, it is clear that tubulin in this organism must be able to form heterodimers in the absence of cofactors. One possible explanation for this is that the sequences of the S. cerevisiae tubulins are the most divergent known. Saccharomyces cerevisiae cells contain only relatively simple microtubule arrays that participate in only three well defined and temporally distinct cellular process mitosis, meiosis, and nuclear fusion. Perhaps this reduced selective pressure on their tubulin genes has allowed the evolution of spontaneously dimerizing tubulin in this organism. 

In 5. cerevisiae and S. pombe, depletion of nitrogen and carbon sources induces diploid cells to undergo meiosis, 3deldlng haploid spores (see Figure 1-5). This process is analogous to... 

In 5. cerevisiae, expression of Gi cycllns (Clns) is repressed throughout meiosis. Melosls-speclflc Ime2 per-... 

In S. cerevisiae, recombination (crossing over) between chromatids of homologous parental chromatids and cohesln cross-links between chromatids distal to the crossover are responsible for synapsis of homologous chromosomes during prophase and metaphase of meiosis I. A specialized cohesln subunit, Rec8, replaces the Sccl cohesln subunit during meiosis. 

Hoilingsworth, N. M., and Johnson, A. D. (1993). A conditional allele of the Saccharomyces cerevisiae HOP gene is suppressed by overexpression of two other meiosis-specific genes REDI and RECI04. Genetics 133, 785-797. 

Johzuka, K., and Ogawa, H. (1995). Interaction of Mrell and Rad50 Two proteins required for DNA repair and meiosis-specific double-strand break formation in Saccharomyces cerevisiae. Genetics 139, 1521-1532. 

Xu, L., Ajimura, M., Padmore, R., Klein, C., and Kleckner, N. (1995). NDT80, a meiosis-specific gene required for exit from pachytene in Saccharomyces cerevisiae. Mol. Cell. Biol. 15,6572-6581. 

Genetic analysis in 5. cerevisiae is performed by hybridizing (mating) haploid strains of opposite mating type, selecting the diploids produced and forcing these to undergo meiosis and sporulation. Sporulation is forced by... 

Ren Q, Yang H, Rosinski M, Conrad MN, Dresser ME, Guacci V, Zhang Z. (2005) Mutation of the cohesin related gene PDS5 causes cell death with predominant apoptotic features in Saccharomyces cerevisiae Auhng early meiosis. Mutat Res 570 163 173. 

Fig. 1.13. Meiosis in S. cerevisiae (Tuite and Oliver, 1991). SPB = spindle pole body DB = dense body SC = synaptonemal complexes, (a) Cell before meiosis (b) dividing of SPB (c) synaptonemal complexes appear (d) separation of the SPB (e) constitution of spindle (metaphase I of meiosis) (f) dividing of the SPB (g) metaphase, n of meiosis (h) end of meiosis formation of ascospores...

S. Sora and M. Carbone, Chloral hydrate, methyl mercury hydroxide and ethidium bromide afifect segregation during meiosis of Saccharomyces cerevisiae, Mutat. Res., 1987, 190, 13-17. 

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