Genetic interactions of hypomorphic mutations in the m⁷G cap-binding pocket of yeast nuclear cap binding complex: An essential role for Cbc2 in meiosis via splicing of MER3 pre-mRNA

An ectopic MER3 cDNA rescues the cbc2-NΔ42 sporulation defect. (A) CBC2 and cbc2-NΔ42 diploids with or without the cSAE3 and cMER3 cDNAs integrated at the chromosomal leu2hisG locus and (B) cbc2-NΔ42 diploids and derivatives with either cSAE3 or cMER3 integrated at leu2hisG were examined by light microscopy at the indicated times after transfer to sporulation medium. The percentages of the cell population comprising four-spore asci are plotted as a function of time.