Gpr22 regulates LR asymmetry through its function in the KV.
(A) WISH on 1–5 somite stage zebrafish embryos using the gpr22 sense or gpr22 antisense probe. Shown are the dorsal views of the tail bud region with anterior to the top. gpr22 is expressed in the axial structures and in the forming KV (arrow). (B, C) Percentage of embryos with randomized southpaw (spaw) expression, injected with (B) water or 0.2 mM gpr22 MO into the yolk at one cell stage (knock down in the whole embryo), or with (C) 1 mM control MO or 1 mM gpr22 MO into the yolk at mid-blastula stage (DFC/KV specific knock down). A DFC/KV specific knock down of gpr22 results in a similar percentage of zebrafish embryos showing randomized southpaw expression as a knock down in the whole embryo. (D) Representative images of panel (C). MO = morpholino, n = number of analyzed embryos, yolksuperscript = injected at one cell stage, DFCsuperscript = injected at mid-blastula stage, WISH = whole-mount in situ hybridization, DFC = dorsal forerunner cell, LR = left-right, KV = Kupffer’s vesicle.