Gβγ signaling is required for the migration, but not differentiation, of PGCs. Embryos injected with RNAs encoding GFP-nos1-3′UTR, either alone (control, 100 pg) or together with Gαt-nos1-3′UTR (50 pg) or Gγ2C68S-nos1-3′UTR (40 pg). Normally localized (arrow) and ectopic (arrowheads) PGCs are indicated. (A-I) Lateral views of embryos showing PGCs labeled with GFP (A-C), expressing nos1 detected by in situ hybridization (D-F) or labeled with vasa-DsRed and GFP (insets show high-magnification images) (G-I). (J-L) The expression of cxcl12a (outlined with magenta dots) and nos1 by in situ hybridization. Dorsal views. Scale bars: 200 μm. (M) The percentage of embryos with PGC migration defects, with the latter defined as more than three PGCs (detected by nos1 expression) per embryo present outside the presumptive gonad region at 24 hpf (Dumstrei et al., 2004). *P<0.01 versus control. (N) Total number of ectopic PGCs per embryo. **P<0.01; #P>0.5 versus control. Data are mean+s.e.m.