The SPS100 gene of Saccharomyces cerevisiae is activated late in the sporulation process and contributes to spore wall maturation.

Abstract

We previously described the use of a differential hybridization screen of a genomic DNA library of Saccharomyces cerevisiae to identify sporulation-specific (SPS) genes (A. Percival-Smith and J. Segall, Mol. Cell. Biol. 4:142-150, 1984 logical events reflects the sequential expression of sporulation-specific genes. Although analyses of in vivo-labeled proteins by one-and two-dimensional gel electrophoresis revealed disappointingly few sporulation-specific proteins (17,20,31,38,45,46), mutational analyses identified a class of genes, termed SPO, dispensable for mitotic growth but essential for the completion of sporulation (10, 39). Expression of the SP013 gene has recently been shown to be developmentally regulated (41). In an alternative approach, genes expressed preferentially during sporulation have been directly identified by differential hybridization screening procedures (4, 13, 28). The transcripts encoded by these genes accumulate before the completion of meiosis (13,16,28). In complementary studies, analyses of the in vitro coding capacities of RNAs isolated from sporulating cells demonstrated the accumulation of an array of sporulationspecific mRNAs most of which also appear before the completion of meiosis (21,44). Two of the sporulationspecific transcripts identified in a study performed by Kurtz and Lindquist, however, begin to accumulate only after spore wall synthesis has begun (22). Interestingly, these two late transcripts, but not the sporulation-specific transcripts which accumulate earlier during meiosis, are present in mature asci (21). This observation prompted us to perform a differential hybridization screen of an S. cerevisiae DNA library using probes prepared with RNA from spores. As described in this report, this screen identified two sporulation-specific genes which are expressed very late during the sporulation process. A mutational analysis revealed that one of these genes contributes to spore wall maturation. 912The the on May 11, 2018 by guest

Mutation of the SPS1-encoded protein kinase of Saccharomyces cerevisiae leads to defects in transcription and morphology during spore formation.

“…In wild-type cells, transcripts corre sponding to these genes accumulated to a high level be tween 11 and 15 hr of sporulation and remained at a high level until 24 hr of sporulation ( Fig. 7E,F; Law and Segall 1988). Accumulation of SPSIOO transcripts was both de layed and reduced in the spsl/spsl strain in sporulation medium (Fig.…”

“…The late SPS genes SPSIOO and SPSlOl are activated ~4 hr after the DIT genes are turned on. The SPSIOO gene has been shov^n to contribute to the development of the ether resistance that is a characteristic of mature spores (Law and Segall 1988). To determine whether mutation of the SPSl gene affected the pattern of sporulation-spe cific gene expression, we monitored accumulation of transcripts of various genes in wild-type cells and in spsl/spsl cells in sporulation medium by Northern blot analysis.…”

“…The probes used in Northern blot analysis to detect various transcripts were as follows: SPSl, a 550-bp Clal-EcoKY fragment from pSPSl-URA3; HOPl, a 3.0-kb £coRI-£coRV fragment from pNH59-2 (HoUingsworth et al 1990); DITl, a 1.8-kb Hindlll-Hindlll fragment from pPB-13 (Briza et al 1990); PYKl, a 1.0-kb Hpal-Hpal (Burke et al 1983) fragment from pPYKlOl (provided by Bryan McNeil); SPS2, a 0.8-kb Pstl-Hindlll fragment from pl8 (Percival-Smith and Seg all 1986); SPS4, p275 digested with Hindlll (Garber and Segall 1986); SPSIOO, a 750-bp BamHl-Ncol fragment from pE18-B8a (Law and Segall 1988); and SPSlOl, pC2 digested with EcoRI (Law and Segall 1988). The probes were radioactively labeled using a random priming method (Feinberg and Vogelstein 1983).…”

“…Cloning and characterization of a large number of the genes identified in these studies have almost invari ably revealed that they are expressed preferentially in sporulating cells (for review, see Mitchell 1994). In con trast, many of the sporulation-specific genes that were identified on the basis of their expression pattern (Clancy et al 1983;Percival-Smith and Segall 1984;Gottlin-Ninfa and Kaback 1986;Law and Segall 1988;Bishop et al 1992;Coe et al 1992) do not appear to have an essential role in the sporulation program (Garber and Segall 1986;Gottlin-Ninfa and Kaback 1986;Percival-Smith and Segall 1986;Law and Segall 1988;Kao et al 1989;Kallal et al 1990;Muthukumar et al 1993). SPSl is one of the few sporulation-specific genes isolated in a differential hybridization screen (Percival-Smith and Segall 1984) that was found to be required for spore for mation (Percival-Smith and Segall 1986).…”

Sporulation in the Budding Yeast Saccharomyces cerevisiae

“…Subsequent to the induction of the mid-late genes, the late genes are induced (Law and Segall 1988;Primig et al 2000). How, or whether, these genes act in spore assembly or maturation is not clear, as no common theme emerges from their known functions.…”