Fig. 8. Developmental time course of mybE expression and identification of a mybE– strain. (A) RT-PCR analysis of a developmental time course. Cells were subjected to development on water agar and total cellular RNA was isolated at the indicated stages. The morphological stages reached at the selected times indicated were: 6 hours streaming, 8 hours loose aggregates, 10 hours tight aggregates, 12 hours standing slugs, 14 hours slugs, 16 hours early-mid culminants and 20 hours mature culminants. The samples were analysed by RT-PCR for mybE mRNA. As a positive control the same samples were analysed for expression of the constitutively active Ig7 gene. (B) Analysis of the mybE gene disruptant by western transfer. Total cellular proteins from a putative mybE– clone and Ax2 were analysed by western transfer using the MybE antibody.