Gpr22 regulates LR asymmetry through its function in the KV.

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