Fig. 8. Abnormal p53 activation in Cx43
1KO PGCs. (A-C)
Genital ridges from E11.5 wild-type and Cx43
1KO mouse embryos were
whole-mount stained using antibody against activated p53 (phospho-serine 15).
PGCs (green) expressing activated p53 (red) are denoted by arrowheads.
Quantitative analysis (C) revealed a marked increase in the expression of
activated p53 in homozygous Cx43
1KO PGCs. This analysis was carried out
using nine Cx43
1 +/+, 16 Cx43
1 +/- and 11 Cx43
1 -/-
explants. (D) Assessment of PGC abundance in E11.5 genital ridges
obtained from embryos of mice injected with
-pifithrin or with vehicle
alone (DMSO). With vehicle injection, homozygous Cx43
1KO mouse embryos
showed a significant reduction in PGC abundance. By contrast, following
-pifithrin treatment there was no difference in PGC abundance in the
wild-type versus heterozygous or homozygous KO embryos. This analysis included
22 Cx43
1 +/+, 28 Cx43
1 +/- and ten Cx43
1 -/-
-pifithrin-treated embryos, and 15 Cx43
1 +/+, 18 Cx43
1
+/- and ten Cx43
1 -/- vehicle-treated embryos. (E) TUNEL
labeling showed that following
-pifithrin treatment the rate of
apoptosis was similar in homozygous KO, heterozygous KO or wild-type PGCs.
Note that the data are normalized to the frequency of TUNEL-positive PGCs
detected in wild-type embryos. This analysis included five Cx43
1 +/+,
37 Cx43
1 +/- and 16 Cx43
1 -/-
-pifithrin-treated genital
ridges. Scale bars: 25 µm.