Fig. 1

Vega1 is activated at the MBT and expressed in a complementary pattern to the dorsal genes, boz/dha and gsc. Whole-mount in situ hybridization of vega1 (A, F-H), boz/dha (B), gsc (C), bmp2b (D), and bmp4 (E and I). (A-G) Dorsal is to the right where known; An, animal view; 75% and 90%, 75% and 90% epiboly stage. Asterisk in dome stage animal view points to vega1-depleted region. (H-I) Anterior is to the left, dorsal up. (F and G) Expression of vega1 is not changed in swirl^tc300/tc300 and chordino^tt250/tt250 mutant embryos at dome stage. Genotyping of mutant embryos was performed by PCR. (H and I) At bud stage, vega1 is partly down-regulated in swirl^tc300/tc300 mutant embryos, whereas bmp4 expression in the posterior region is abolished. (J) Transverse section of shield stage embryo stained by in situ hybridization for vega1 or dkk1. It is noteworthy that the dkk1 expression domain is vega1 negative. Arrows indicate yolk syncytial layer.