Fig. 4

Expression patterns of Xlslit2 and Xlrobo2 and morphology of axonal tracts in Xenopus larvae. a–c Transcripts of Xlslit2 are detected through the dorsal midline in the diencephalon at stage 32 (a), stage 40 (b) and stage 44 (c). Xlslit2-weak gap is found between diencephalon and mesencephalon (arrows in A and C, A’ is a dorsal view). In the metencephalon (met), expression domains of Xlslit2 are observed along the antero-posterior axis (arrowheads). d–f Expression pattern of Xlrobo2 at stage 32 (d), stage 40 (e) and stage 44 (f). (d) At early tail-bud stage, Xlrobo2 is expressed in the telencephalon (te), diencephalon (di), mesencephalon (mes), dorsal metencephalon (met) and notochord (nc). e, f At middle and late tail-bud stage, XlRobo2 expression is detected at high levels in the dorsal CNS. g, h Dorsal (g) and lateral (h) view of the developing Xenopus larva at stage 46. Axons in the PNS and CNS are visualized by anti-acetylated tubulin antibody. Habenular and posterior commissures are located the diencephalon (HC and PC). Scale bars: A-F, 200 μm; G and H, 500 μm