FIG. 5.

Sporulation-specific expression of DTR1. (A) Northern analysis of DTR1 and other sporulation-specific genes. Total RNA isolated from the wild-type strain SK1 at different times of sporulation was hybridized with radiolabeled probes consisting of DNA fragments of the indicated genes. As a control, ethidium bromide-stained rRNA was used. (B) Correlation of DTR1 expression (•) and dityrosine synthesis (□). The relative levels of DTR1 expression was determined by densitometry of the autoradiograph. Dityrosine was analyzed in the hydrolyzates of the cell debris after RNA extraction, thereby ensuring maximum synchronicity between the expression data and the biochemical data. (C) DTR1 is not expressed in asporogenous MATa/a and MATα/α cells. Northern analysis of RNA isolated after 24 h in sporulation medium from three isogenic diploids of the mating type MATa/MATa, MATa/MATα, and MATα/MATα (strain background LP112).