Fig. 10

Expression of Ino-Pax2/5/8 during late prehatching development of the cephalopod Idiosepius notoides. Dorsal (d)–ventral (v), anterior (ant)-posterior (p), and left (l)-right (r) axes indicate the orientation. Yolk sac (y) removed in (a-c) Arms are labeled with numbers. a Stage 24 individuals express Ino-Pax2/5/8 in all arms, the eyes (ey), the epidermis of the cephalopedal region, the interbasal lobes (arrowheads), the posterior basal lobes (pb), and the anterior basal lobes (ab). Note the unspecific staining around the shell gland (sg). b Same stage 24 individual as shown in (a) Note Ino-Pax2/5/8 expression in the proximal optic lobes (o), the eyes, and the funnel (fn). c Ino-Pax2/5/8 is expressed in smaller portions of the body of stage 25 individuals compared to earlier stage individuals. Ino-Pax2/5/8 is expressed in the gills (g), the eyes, and in the proximal but not the distal arm portions. Note Ino-Pax2/5/8 expression in the interbasal lobes (arrowheads). d The interbasal lobes (arrowhead) and anterior basal lobes of the supraesophageal mass (se) express Ino-Pax2/5/8. The posterior perikaryal layer of the middle subesophageal mass (ms) as well as the posterior subesophageal mass (ps) express Ino-Pax2/5/8. Ino-Pax2/5/8 expression could not be observed in the distal funnel of this stage 25 individual. Please note the unspecific staining around the statocyst (sc). e-h In stage 27 individuals, Ino-Pax2/5/8 is restricted to few expression domains such as the gills, the posterior perikaryal layer of the middle subesophageal mass, the interbasal lobes (arrowheads), tissue around the buccal mass (bm), and the base of the funnel. Trajectory of esophagus is indicated by red dashed line in (h). Abbreviations: bk, beak; is, ink sac; iy, internal yolk; se, supraesophageal mass. Scale bars: (a-d) 150 μm; E-H: 200 μm