Fig. 5. Lvalx1 is upstream of the signal that suppresses NSM transfating. (A) Experimental protocol. (B-G) Recombinant embryos were photographed using brightfield (upper row) and epifluorescence (lower row) optics. (B,E) Animal cap + micromere recombinant, 36 hours after fertilization. Micromere progeny (labeled with Rhodamine dextran) have formed the embryonic skeleton (arrow) and have induced the formation of a complete embryonic axis. (C,F) Animal cap + LvAlx1 MO-micromere recombinant, 48 hours after fertilization. LvAlx1 MO-injected micromeres have induced a complete embryonic axis. In contrast to B,E, however, the progeny of the micromeres (labeled with fluorescein dextran) are not arranged along the skeletal rods (C, arrowhead). Instead, they are scattered in the blastocoel or remain associated with the tip of the archenteron (arrow). (D,G) Animal cap + LvAlx1 MO-micromere recombinant, 48 hours after fertilization. Mesomere descendants have transfated, as shown by 6a9 immunostaining, and are associated with skeletal elements (G, arrow).