Figure 6. Increased cell death is observed in Nle1^mcKO mutant embryos.

A. E9.5 and E10.5 control and mutant embryos were incubated in LysoTracker Red solution. Normal developmental apoptosis was observed in the head (E9.5 and E10.5) and in the ventral part of the somites (E10.5) of control embryos. In Nle1^mcKO embryos, apoptosis in the head was similar as control embryos, whereas a marked increase in apoptosis was observed in the neural tube and the entire somites at E9.5 (n = 2 mutants and n = 6 controls including 2 Meox2^Cre embryos) and E10.5 (n = 3 mutants and n = 8 controls including 2 Meox2^Cre embryos). B. Immunostaining for the active form of caspase3 protein in E9.5 control and Nle1^mcKO embryos. Representative results of immunostaining of transverse section of the caudal part of embryos are shown. In Nle1^mcKO embryos, high number of apoptotic cells was observed (arrowheads) in the neural tube and the somites. (n = 3 mutants and n = 4 controls including a Meox2^Cre embryo). No increase in apoptosis was observed due to the expression of the Meox2^Cre allele.