Fig. 3

Fig. 3 Maternal nos1 is required for primordial germ cell survival. (A) Numbers of germ cells in embryos at the stages identified on the X axis as assayed by in situ hybridization using a vasa probe. Shield and 14-somite stage embryos were derived from a cross between nos1^-/- females and nos1^+/+ males, while 17-somite stage embryos were derived from a cross between nos1^-/- parents. Standard deviations and numbers of embryos analyzed for each class are indicated. In legend, Mnos1^- indicates embryos derived from nos1^-/- females. PGC localization in representative shield-stage embryos derived from nos1^+/+ females (B) or nos1^-/- females (C) as revealed by vasa in situ hybridization (blue). PGC localization in representative 17-somite stage embryos stained for myod and egr2b in red, and vasa in blue, derived from nos1^+/+ females (D), nos1^-/- females (E) or nos1^-/- females injected with 200 pg synthetic nos1 mRNA (F). Arrows point to correctly localized vasa expressing PGCs, while arrowheads indicate ectopically localized PGCs. Germ cell development in Mnos1 embryos can be rescued by injection of nos1(wt) RNA (G; n = 12/12) but not nos1(fh49) mutant RNA (H; n = 0/23) at the one-cell stage, as assayed in a 24 hpf embryo. Arrow in panel G points to EGFP expressing germ cells (see Materials and methods). Scale bars: 100 μm.