Fig. 6. ced-9 acts downstream of the Pax2/5/8 genes. (A) ced-9 and mev-1 transcript abundance is altered in response to Pax2/5/8 gene activity. Quantitative RT-PCR results for ced-9, mev-1, ced-3, ced-4 and egl-1 genes in different Pax2/5/8 genetic backgrounds, normalized to the act-2 gene. Wild type (N2) and dpy-20 [the genetic background for egl-38(n578)] serve as controls. ced-9 and mev-1 transcript abundance is decreased in egl-38 pax-2 double mutants, and increased in response to induced expression of egl-38 or pax-2 (hsp::egl-38 and hsp::pax-2). The transcript abundance of the other cell death pathway genes is unaltered. Separate experiments indicate that ced-9 and mev-1 abundance is not altered in response to heat-shock in wild-type animals (data not shown). Error bars indicate standard deviation. (B) Induced expression of ced-9 can bypass the cell death defect of pax-2 egl-38 double mutants. By contrast, induced expression of mev-1 alone, or in combination with ced-9, does not significantly impact the cell death effect. Induced expression of pax-2 in wild type and pax-2 egl-38 mutants is included as a control. Data presented as in Fig. 1.