Fig. 3.

Expression of ceh-51. (A,B) ceh-51 transcripts occur in (A) the MS daughter cells (MS²) and (B) in the MS granddaughters (MS⁴), as detected by in situ hybridization. The E daughters are outlined. Ninety-one percent (n=101) of embryos at this stage showed expression in MS² or MS⁴ (nine embryos did not stain). (C) Ectopic expression of ceh-51 following heat shock of hs-tbx-35 embryos. (D) Eighty-six percent (n=44) of pop-1(RNAi) embryos showed ceh-51 mRNA in both the MS and E daughters. Two embryos showed normal expression and four embryos did not stain. (E) Embryos transgenic for a ceh-51::GFP transcriptional reporter with 788 bp of upstream sequence show expression at MS⁴ that persists in later MS descendants. (F) A translational ceh-51::GFP::CEH-51 fusion shows strong nuclear accumulation at MS⁸. (G) ceh-51::GFP is undetectable in med-1(ok804); med-2(cx9744) embryos (n=84). (H) Sixty-six percent (n=41) of pop-1(RNAi) embryos showed ceh-51::GFP in both the MS and E lineages (the remainder were similar to wild type). (I,J) mex-1(RNAi) (I) and pie-1(RNAi) (J) embryos displayed ectopic ceh-51::GFP in AB and C descendants. (K) In tbx-35(tm1789) embryos, the onset of ceh-51::GFP expression was undetectable (52%, n=89) or delayed until past the MS⁸ stage (48%) and at lower levels. The exposure in this image was 10-fold longer than that shown in E. (L) ceh-51::GFP was not detected in tbx-35(tm1789); pop-1(RNAi) embryos (n=49).