Fig. 2

Zebrafish TJP expression patterns during early embryonic development. All figures depicting expression patterns show the embryos in the same orientation: anterior to the left, posterior to the right, dorsal to the top and ventral to the bottom. Expression of tjp1.1 (A,F,K), tjp1.2 (B,G,L), tjp2.1 (C,H,M), tjp2.2 (D,I,N) and tjp3 (E,J,O) was detected by whole mount in situ hybridization of embryos at the 64 cell stage (2 hpf) (A–E), at the sphere stage (4 hpf) (F–J) and at the shield stage (6 hpf) (K–O). Messenger RNA for all TJPs is maternally supplied (A–E). Hybridization signals remain strong after the midblastula transition, when embryonic transcription begins (F–J). Tjp2.1 mRNA is excluded from the nucleus (C, H, arrows), whereas tjp2.2 accumulates in the nucleus (D, I, arrows). At the stage of early gastrulation, TJP expression is weak but uniform (K–O). Tjp3 mRNA shows perinuclear localization (O, inset).