Fig. 8. Summary of G2-M transition in wild-type and phyl mutant SOPs. In wild-type pupae at 12 hours APF, Ac and Sc (shown in red) are enriched in newly specified SOPs. High levels of Ac and Sc proteins then further activate transcription of phyl, which in turn mediates Ac and Sc degradation between 12 and 14 hours APF. Depletion of Ac and Sc from SOPs at 14 hours APF leads to stg expression and the subsequent G2-M transition. Five daughter cells are generated by 24 hours APF. In phyl mutant SOPs, accumulation of Ac and Sc represses stg expression, leading to defects in G2-M transition. Most of the SOPs in phyl² clones remain undivided between 12 and 24 hours APF. ^*In phyl² mutant clones, Ac expression between 20 and 24 hours APF, and Sc expression between 16 and 24 hours APF are not determined.