Fig. 5

Antivin inhibits mesoderm induction at blastula stage. Wild-type control embryos (A,C,E,I,K) and embryos injected with 0.5 pg (B), 1 pg (D,F), 2 pg (G), 5 pg (H,J,L) antivin RNA were analyzed by in situ hybridization with a marker of prechordal mesoderm, gsc (A,B), a panmesodermal marker, ntl (C-H) or the AS11 marker which labels the margin and the presumptive brain territory (I-L). (B) Injection of antivin RNA inhibits gsc expression (delimited by arrows). (D) Lateral view of an embryo depicting the loss of ntl expression in the marginal zone (MZ, delimited by arrows) along the animal to vegetal pole axis. (F-H) Increasing doses of antivin RNA lead to a progressive deletion (arrows) of the presumptive mesoderm. (H) Detectable expression of ntl is located in cells fated to form the tail bud. (J-L) Labelling with AS11 confirms the complete loss of the marginal zone. Expression of AS11 in presumptive brain (pb) extends down to the margin (arrowheads). Embryos are shown in polar views, except for C,D,I,J, which are lateral views. Scale bar: 150 μm.