Figure 3: Prdx4 genetically interacts with GDE2 to control the timing of neurogenesis.

(a–c,e–g) Sections of mouse embryonic spinal cords stained for cell cycle analysis. BrdU labelling was performed 16 h (a,e) or 30 min before analysis (c,g). (d) Graphs quantifying different phases of the cell cycle. Mean±s.e.m., n=3–7 embryos; cell cycle exit *P=0.0321; M-phase P=0.7474; total number of BrdU⁺Ki67⁺ cells (16 h) *P=0.0111; S-phase P=0.4660, two-tailed Student’s t-test. (h) Graphs quantifying ratios of motor columns compared with WT animals. Mean±s.e.m., n=4–5 embryos; medial median motor column (MMCm) P=0.5395; medial divisions of lateral motor column (LMCm) *P=0.0154; lateral divisions of lateral motor column (LMCl) *P=0.0025; two-tailed Student’s t-test; lower panels are schematics showing changes in motor columns in the absence of Prdx4. (i) Graphs quantifying ratios of motor pools compared with WT animals. Mean±s.e.m., n=5–6 embryos; Al (adductor longus)+Am (adductor magnus)+Gp (gracilis posterior) *P=0.0385; Va (vasti) *P=0.0003; Ab (adductor brevis) *P=0.0159; two-tailed Student’s t-test; lower panels are schematics showing changes in motor pools in Prdx4 KOs. (j,k) Sections of E9.5 mouse spinal cords. Arrows mark newly differentiating Olig2⁺Isl⁺ cells; arrowheads mark postmitotic Isl motor neurons. (l) Graphs quantifying ratios of Olig2⁺Isl⁺ cells and Isl⁺ cells compared with Prdx4 mutant animals. Mean±s.e.m., n=6–8 embryos; Isl⁺ *P=0.01; Olig2⁺Isl⁺ *P=0.0001; two-tailed Student’s t-test. Scale bars, 20 μm.