Figure 5.

Expression patterns of nosA and nosB in larvae of the arctic lamprey. At stages 24–25 the nosA is expressed in the brain, mouth, upper and lower lip, dorsal midline epidermis, and cloaca (a). At stage 28, nosA expression is restricted to the mouth (b). The nosB is exclusively expressed in the cheek process, consisting of upper and lower lips (c,d), and faint expression in the dorsal midline epidermis (c). br, brain; cl, cloaca; dme, dorsal midline epidermis; gp, gill pouches; mo, mouth; ll, lower lip; ul, upper lip; lv, lateral view; vv, ventral view. Scale bar in (a) is 0.5 mm. (Online version in colour.)