Figure 1

Early HDAC mRNA injection induces heterotaxia. (A) Xenopus HDAC mRNA expression pattern is shown by in situ hybridization with early Xenopus embryos. HDAC mRNA presents a symmetric expression pattern by animal cells at the stage 3 (4 cells) (a,b,c), at the stage 5 (16 cells) (d,e,f) and at the stage 7 (64 cells) (g,h,i). in situ reaction control with no secondary (j, animal view) or no probe added to the reaction (k, animal view; l, vegetal view). (B) Embryos injected with HDAC DN on the ventral or dorsal right blastomeres presented significant levels of heterotaxia (VR 20% heterotaxia p < 0.01, n = 55; DR 19% heteroatxia p < 0.01, n = 42; VL 7% heterotaxia p = 0.3 n = 55; DL 2% heterotaxia p = 0.7). Embryos injected with HDAC WT on the ventral left side presented significant levels of heteroatxia (VL 19% heterotaxia p < 0.01, n = 68; VR 4% heterotaxia p = 0.8, n = 49; DL 4% heteroataxia p = 0.8, n = 44; DR 2% heterotaxia p = 0.5, n = 50). (B`) Schematic showing the injected blastomere at the 4 cell stage. (I) Wild type phenotype showing the gut coil to left (yellow arrow), the gall bladder on the right (green arrow) and the heart loop on right (red line). (II) Situs inversus phenotype where all three organs analyzed are found inverted. (III) Heterotaxic phenotype showing the heart loop to the left (red arrow).