Removal of Wnt5a or Ror2 disrupts PGC proliferation in distinct locations. (A) The frequency of EdU incorporation is elevated in Ror2^Y324C PGCs in the hindgut compared with WT or Ror2^Y324C/+ controls. EdU was given 4 h before dissection. n = 97–1,056 cells from nine WT/het embryos and ten mutant embryos; *, P = 0.04 by Fisher’s exact test. (B) Mean number of PGCs counted in histological sections at different ages. P values by Student’s t test for section counts. Estimates for total numbers of WT/het and Ror2^Y324C PGCs per embryo were calculated using the multiplier of 100× for E9.5, 125× for E10.5, and 150× for E11.5 based on reported cell counts (Tam and Snow, 1981; Laird et al., 2011). (C) Frequency of EdU incorporation in E9.5 WT/Ror2^Y324C/+ PGCs and Ror2^Y324C PGCs in different locations. *, P = 0.03 by Fisher’s exact test. (D) Distribution of EdU⁺ PGCs by location at E9.5 in WT/Ror2^Y324C/+ PGCs and Ror2^Y324C embryos. (E) Frequency of EdU incorporation in WT or Wnt5a^+/− PGCs and Wnt5a^−/− PGCs in different locations throughout migration. n = 70–761 cells from nine WT/het embryos and ten mutant embryos. (F) Mean number of PGCs counted in histological sections at different ages. P values by Student’s t test for section counts. Estimates for total numbers of WT/het and Wnt5a^−/− PGCs per embryo were calculated using the multiplier of 100× for E9.5, 125× for E10.5, and 150× for E11.5 based on reported cell counts. (G) Frequency of EdU incorporation in E9.5 WT/Wnt5a^+/− PGCs and Wnt5a^−/− PGCs in different locations throughout migration. *, P = 0.02 by Fisher’s exact test. (H) Distribution of EdU⁺ PGCs by location at E9.5 in WT/Wnt5a^+/− and Wnt5a^−/− embryos. Error bars in A, C, E and G indicate standard error of the mean.