Dampened activity of E2F1–DP and Myb–MuvB transcription factors inDrosophilaendocycling cells

• DOI: 10.1242/jcs.064519
• Publication Date: 2010-11-03T01:59:42Z
• Authors: Shahina B. Maqbool; Sonam Mehrotra; Alexis Kolpakas; Chris Durden; Bingqing Zhang; Hua Zhong; Brian R. Calvi
• Keywords: MYB; E2F1; Transcription

The endocycle is a variant cell cycle comprised of alternating gap (G) and DNA synthesis (S) phases (endoreplication) without mitosis (M), which results in polyploidy large size. Endocycles occur widely nature, but much remains to be learned about the regulation this modified cycle. Here, we compared gene expression profiles mitotic cycling larval brain disc cells with endocycling fat body salivary gland Drosophila larva. indicated that many genes are positively regulated by heterodimeric E2F1–DP or Myb–MuvB complex transcription factors expressed at lower levels cells. Many these target have functions M phase, suggesting dampened E2F1 Myb activity promote endocycles. other required for replication were also repressed cells, an unexpected result given must duplicate up thousands genome copies during each S phase. For some EF2-regulated genes, level mRNA resulted protein concentration, whereas it did not, contribution post-transcriptional regulation. Both knockdown overexpression impaired endocycles, indicating transcriptional activation repression balanced. Our data suggest important repress coordinate stability oscillators.