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Fig. 2. Somatic RNA clearance is mediated by LEs of other vegetally localized mRNAs expressed in the germ line. (A–F) GFP-tagged LE reporter mRNAs of Xcat2 (A, 800 pg), XDazl (B, 800 pg), Xpat (C, 800 pg), VegT (1.2 ng), Vg1 (1.2 ng), Dead end (XDE-LE, 1.2 ng), or lacZ-tagged LE mRNAs (2 ng each) of the DeadSouth isoform (D) Velo76, XNIF, Velo 40, and Velo7 were injected vegetally into both blastomeres of two-cell-stage embryos. Embryos (stage 30–32) were analyzed for reporter RNA distribution by in situ hybridization using antisense GFP or lacZ probes. (G) LEs of the majority of vegetally localized mRNAs expressed in the germ line were found to mediate germ-line restriction of reporter RNAs irrespective of their transport pathway. Values for PGC stabilization indicate the percentage of embryos exhibiting PGC-specific reporter RNA staining (Fig. S5). Asterisk indicates that for Vg1 (E), VegT (F), and Velo7, PGC staining was detectable in <10% of injected embryos and accompanied by high somatic levels or reporter RNA (100%, 98.6%, and 46.7% of injected embryos, respectively). |