Variations in mRNA transcript levels of cell wall-associated genes of Saccharomyces cerevisiae following spheroplasting.

mRNA transcript levels of 38 genes from Saccharomyces cerevisiae were investigated during attempted spheroplast regeneration. Many of the genes selected are involved in cell wall biosynthesis. Spheroplasts did not regenerate into osmotically competent cells during the experiment. However, at a mRNA level, the quantities of transcripts were altered between the experimental and control populations. KRE11, EGT2 and MSS10 had their transcript levels increased by more than 10-fold during attempted spheroplast regeneration. A further six genes, FLO1, TIR1, SED1, HKR1, YGR189 and MUC1, showed transcript level increases of at least 5-fold. Five genes showed a change in transcript levels from an undetectable level to a detectable level: SKT5, KRE1, KRE5, SEC53 and DHS1. PMT2 showed a rapid decrease in mRNA levels followed by an increase to the basal level. Thus, cell stress genes, biosynthetic genes and some glycosylphosphatidylinositol-anchored cell wall proteins have their transcript levels increased in regenerating spheroplasts, but their transcription was not sufficient to initiate the replacement of the cell wall in liquid medium.