Rescue of the QKD phenotype by exogenous B1 sox mRNAs.
(A, B) Uninjected control (Ctr) embryos (A) and the QKD embryos (B). Live embryos were observed at 10–11 (a), 15–16 (b) and 30–31 (c) hpf. Expression of hesx1, pax2a and hoxb1b (d), dlx3b, hgg1 and ntl (e), and neurog1 (f) was visualized by whole-mount in situ hybridization. Lateral views (a–c); dorsal views with anterior to the top (d–f). (C) The QKD phenotype is similarly rescued by an exogenous supply of any B1 sox mRNA. The MOs for QKD were coinjected with the indicated mRNAs. In the B1 sox mRNA-coinjected embryos, the expression of hesx1, dlx3b and nuerog1 was recovered; patterning of the neural plate marked by pax2a and hoxb1b was normalized; and the expression patterns of hgg1, ntl and dlx3b reflecting C&E movements were also restored. Blue bracket, gap between the hgg1 and ntl expression domains; white dotted line, neural plate border. (D) Recovery of the AP axis elongation in QKD embryos injected with one of the B1 sox mRNAs. The length of the embryos at 15–16 hpf along the AP axis between the arrowheads (Ab, Bb, Cb) was measured for the uninjected control (Ctr) (n = 7), the QKD (n = 9) and QKD with B1 sox mRNA injection (sox2, n = 9; sox3, n = 6; sox19a, n = 7; sox19b, n = 6). The average AP axis lengths with standard errors are shown.