Left-right defects in sec10MO embryos.

Left-right defects assayed at the level of asymmetric gene expression and organ placement as described [31]. Embryos were scored by in situ hybridization for asymmetric gene expression of spaw (in the lateral plate mesoderm), lefty2 (in the heart), and lefty1 (in the diencephalon) by in situ hybridization at approximately 19 somite stage (19ss). Embryos were scored for the laterality of organ placement using myl7 (in the heart), foxa3 (in the liver), and insulin (in the pancreas) at 2 dpf. Situs solitus = right-looped heart, left-sided liver, right-sided pancreas. Situs inversus = left-looped heart, right-sided liver, left-sided pancreas. Heterotaxia = all other organ conformations. P values reported are from Fisher's exact test, comparing the given row against uninjected embryos. We also employed the same test to compare the effects of the various treatments. All treatments differed from one another in their effects on both gene expression and organ placement (p = 0.003–2.08x10-7) except for the effects of 4ng pkd2MO and 8+8ng sec10MO on organ placement, which were statistically indistinguishable (p = 0.19).