As Wg signaling also leads to down regulation of the es sential mitotic regulator Cdc25 phosphatase String across the G2 band of the margin selleckbio at the level of transcrip tion, we used a stg lacZ enhancer trap to monitor stg pro moter activity. Distribution of the stg lacZ enhancer trap and Wg protein shows stg promoter activity overlapping with Wg in the G1 cells of the margin, decreased in the G2 delayed cells, and abundant throughout the remainder of the pouch. Surpris ingly, rather than leading to decreased stg promoter activ ity, as would be predicted given the expansion of the Wg domain in the EcR RNAi clones, EcR knock down increases stg lacZ activity in clones spanning the margin. Together the data suggests that disruption to cell cycle patterning across the Inhibitors,Modulators,Libraries margin in the EcR RNAi clones is unlikely to be due to direct effects on dMyc, E2F or Stg.
EcR is essential for CycB patterning across the wing margin The finding that dMyc is not altered and stg is ectopi cally expressed led us to investigate whether EcR Inhibitors,Modulators,Libraries might normally modulate cell cycle in the margin via Inhibitors,Modulators,Libraries the key G2 M cyclin, Cyclin B, which is also essential and rate limiting for G2 M progression. For this we first used a Cyclin B GFP protein trap to monitor CycB expression in the wing. The CycB PT reflects the pattern of CycB protein distribution in the wing and the anti EcR antibody and the CycB PT overlap throughout the wing pouch. The result of EcR knock down is striking, with EcR RNAi clones spanning the margin having dramatically decreased CycB PT activity, particularly within the band of Inhibitors,Modulators,Libraries cells normally arrested in G2.
Inhibitors,Modulators,Libraries To confirm that EcR RNAi also affects the distribution of CycB protein in a similar manner to the GFP protein trap, we used the CycB antibody. In line with the CycB PT data, EcR knockdown also results in decreased CycB protein across the margin. Dovitinib manufacturer The decreased CycB together with the elevated PCNA GFP further suggested that EcR RNAi clones spanning the G2 region of the margin were experiencing a G1 delay. To further investigate whether the G2 delay was disrupted in EcR loss of function cells at the margin, we co stained for the DNA replication inhibitor Geminin, which like CycB is usually abundant from the end of S phase, peaks in G2 and is degraded at the anaphase metaphase transition. Indeed, consistent with EcR RNAi disrupting the G2 delay, we observe de creased Geminin in the presumptive G2 band, with G2 cells only observed at the position normally occupied by the G1 band. To gether the cell cycle analysis for EcR RNAi clones suggests that EcR is normally required for expression of CycB, but for repression of Stg throughout this region of the margin.