Meiosis-specific genes are regulated posttranscriptionally by splicing. PCR products, from primers that surround intronic sequences in 16 meiotic genes (designated above), were separated by using gel electrophoresis on an agarose gel stained with SYBR green. The image color has been inverted for clarity; bands of DNA appear dark on a light background. For each gene, five PCRs were carried out under identical conditions by using five different SK1-derived templates: total RNA (RNA) as a control for genomic contamination, genomic DNA (gDNA), cDNA from cells grown in rich media after 0 hours of sporulation (0h), cDNA from cells harvested after 4 (4h) or 8 (8h) hours of sporulation. The larger PCR products result from genomic DNA in the gDNA lanes or unspliced pre-mRNA in the 0h, 4h, and 8h lanes. The smaller products result from spliced mRNA. The marker (m) is a 50-bp marker. All 13 meiosis-specific genes perform regulated splicing. Only GLC7, TUB1, and TUB3, which have important cellular functions outside of meiosis, are completely spliced in rich media and do not display regulated splicing activity.