Fig. 7

Gene expression during Schmidt’s larva formation in Lineus ruber. A–AA′′ Whole-mount in situ hybridization in blastulae, gastrulae and Schmidt’s larvae of L. ruber. A–C′′ foxQ2 is expressed in the anterior region of the Schmidt’s larva. D–F′′ six3/6 is expressed in the anterior cephalic imaginal discs and in the anterior mouth. G–I′′ gsc is detected in two ventro-lateral clusters at each side of the blastopore (arrowheads H) and mouth. J–L′′ otx is expressed around the blastopore opening, and in the anterior imaginal discs and gut of Schmidt’s larva. M–O′′ foxA is expressed in the mouth and larval pharynx. P–R′′ GATA456-a is detected in the blind gut of the larva. S–U′′ twi-a is expressed in all imaginal discs of the larva. V–X′′ evx is expressed in one pole of the blastula (arrowhead V), one side of the gastrula and in the posterior end of the Schmidt’s larva. Y–AA′′ cdx is weakly detected in the posterior end of the larva (arrowhead in AA′′). All panels of blastula embryos are lateral views, and panels of gastrulae are blastoporal views. In the Schmidt’s larva, panels on the left are ventral views and panels on the right side are lateral views. In all cases, anterior of the Schmidt’s larva is to the left. bp blastopore, mo mouth