Figure 3.

Respiratory failure and PMC loss in Hox5 ^MNΔ mice. (a–b) All Hox5^MNΔ mice are born cyanotic and perish at birth. (c–d) Histological analysis reveals that the lungs of e18.5 Hox5^MNΔ embryos collapse before birth. (e–n) Progressive loss of Scip+ PMC neurons in Hox5^MNΔ mice. At e11.5 Scip+ neuron numbers are similar between control and Hox5^MNΔ mice but progressively decrease in the mutants. By e17.5 there are no detectable Scip+ motor neurons in Hox5^MN mice. (o) Quantification of Scip+ motor neurons in control and Hox5^MNΔ mice. At least 5 pairs of embryos were analyzed for each time point. *P<0.05, ***P<0.001 (p) Quantification of non-LMC Isl1/2+ motor neurons. There is selective loss of FoxP1− neurons in Hox5^MNΔ mice. (q–r) PMC disorganization at e12.5 in Hox5^MN mice. Isl1/2+ Scip– neurons are intercalated with PMC neurons. (s–t) ALCAM expression is reduced in Hox5^MN mice, as early as e11.5 prior to loss of Scip. (u–z) Lynx2, RTN4 and PTN are downregulated in Hox5^MN mice at e12.5. PMC position is outlined by dashed red line. Expression of Lynx2 is also lost from LMC neurons. Scale bars=25μm, except in (b)=1cm and (d)=100μm. Error bars represent s.e.m.