Figure 5. CEP-1/p53 Protein Levels Are Upregulated in
gld-1 Mutant Germlines. (A) Wild-type (upper) and
gld-1(
op236) (lower) germlines from hermaphrodites grown at the restrictive temperature (25 C) and dissected 16 hr post L4 larval stage and stained with anti-CEP-1 antibodies (green) and DAPI (blue). To detect quantitative differences in staining intensities, nonsaturating pictures were taken. The various stages of germ cells in the dissected gonad are indicated in the corresponding upper DAPI-stained germlines.(B)
gld-1(null) worms (grown at 20 C) were dissected 24 hr post L4 and treated similarly as in (A) but exposure time was 5 times shorter, indicative of highly upregulated CEP-1/p53 levels.(C) Quantification of the number of pachytene germline nuclei with CEP-1 staining in wild-type and
gld-1(
op236) at the restrictive temperature (25 C) as well as at the semipermissive temperature in the presence and absence of IR treatment (n = 11-15). The number of CEP-1-positive pachytene cells (as defined by their DAPI morphology) was identified by their distinct nuclear CEP-1 staining in dissected germline preparations.(D) Dissected germline of a CEP-1::GFP fusions with the 3'UTR of
cep-1/p53 (top panel) and with the 3'UTR of
let-858 (bottom panel). Note that the distal tip cell area of the germline in the bottom panel is out of focus. The CEP-1::GFP fusion transgene only leads to partial rescue of the IR-induced apoptosis phenotype of
cep-1(null), possibly because the GFP fusion, which is close to the CEP-1/p53 tetramerization domain, compromises its activity (R.H. and M.H., unpublished data).