Expression of klf2a in the pharyngula-stage zebrafish embryo.

Whole-mount in situ hybridization of zebrafish embryos with riboprobe for the zebrafish klf2a gene. Embryos are shown in lateral view with anterior to the left and dorsal up. Scale bars are 100 μm (A,C) and 50 μm (B). (A) Trunk and tail of a 24-hour post-fertilization (hpf) embryo showing klf2a expression in cells closely associated with the axial vessels (black arrowheads), the anus (arrow), and superficial cell clusters (white arrowhead). (B) Head of a 24-hpf embryo showing klf2a expression in head vessels (arrowheads) and heart (arrow, out of plane of focus). (C) Trunk and tail of a 36-hpf embryo showing klf2a expression denoted as in panel A. Original magnification in panels A and C 100 ×, panel B 200 ×; stained with NBT/BCIP precipitate.