Figure 2. Transcription of
egl-1 correlates with programmed cell death. Nomarski optics (A,C,E) and epifluorescence (B,D,F) of the posterior ventral nerve cord of L3 stage larvae carrying an integrated Pegl-1histone:gfp reporter construct localized to nuclei. The descendants of P11.aaa are reproducibly located immediately posterior to the hypodermal cell P10.p. (A,B) In
ced-3; Pegl-1histone:gfp transgenic animals (30 out of 30 animals),
egl-1 is expressed in the two cells that undergo programmed cell death in the P11 lineage (P11.aap and P11.aaap). (C,D) In
mab-5(
n1384);
ced-3; Pegl-1histone:gfp transgenic mutants, the
egl-1 transcriptional reporter is not expressed (27 of 30 mutants) in P11.aaap, which survives in
mab-5 mutants. (E,F) In
ceh-20(
ay42);
ced-3; Pegl-1histone:gfp mutants, the
egl-1 reporter is not expressed (58 out of 60 mutants) in P11.aaap, which survives in
mab-5 and
ceh-20 mutants. The P12 lineage descendants arise in the preanal ganglion, which contains other neuronal cells; consequently, we were unable to identify unambiguously P12.aaap. However, the Pegl-1histone:gfp reporter was expressed in two rather than three cells in the preanal ganglion of
mab-5 and
ceh-20 mutants.