Fig. 4. Effects of tBR RNA injection on VBI and DLP development. tBR RNA (800 pg-1 ng total) was injected either into the VMZ or DMZ of four-cell stage embryos and the effects on VBI and DLP development analysed by whole-mount in situ hybridisation of stage 26 embryos. Row 1, globin expression; row 2, Xaml expression; rows 3 and 4, SCL expression; rows 5 and 6, Xfli1 expression; and rows 7 and 8, XHex expression. Rows 1,2,4,6,8, ventral views; rows 3,5,7, lateral views. t, tail; h, head. Anterior is towards the left unless otherwise stated. In rows 3, 5 and 7, dorsal is towards the top. Black arrows indicate the DLP; red arrows indicate the vitelline veins; black arrowheads indicate the developing liver. Staining for a particular gene was performed for the same time in all treatments.