Fig. 3

Stabilization of zebrafish vasa and translational regulation of medaka olvas mRNA in PGCs of medaka. 100 pg of GFP tagged fusion RNAs were injected at the 2-cell stage. (A to D) The embryos were fixed at early somitogenesis and at 12-somite stage and in situ hybridization using a GFP antisense RNA probe was performed to reveal the spatial distribution of the injected RNAs. In the control embryos the GFP-globin RNA is degraded uniformly in all cells (A and C) whereas in vasa-GFP injected embryos (B and D), the PGCs retain the injected RNA (arrows in D) while it is degrading in somatic cells. (E to S) olvas-GFP (E to I) as well as GFP-zfvasa 3′UTR (J to N) constructs were injected in medaka and followed for GFP expression and compared to control GFP-β globin 3′UTR injected embryos (O to S). Interestingly, in medaka, olvas-GFP protein expression was rapidly restricted to PGCs (E to I), while zebrafish vasa 3′UTR did not induced selective GFP expression.