Heterosis of mule was revealed by induced pluripotent stem cells

We examined the growth curve, cell cycle, apoptosis and glycolysis of donkey, horse and mule adult fibroblasts (DAFs, HAFs and MAFs), which indicated there are differences in cell proliferation and metabolism. We also derived mule, donkey and horse iPSCs from their respective adult fibroblasts by piggyBac transposition, and we found the induced reprogramming efficiency of mule iPSCs was significantly higher than donkey and horse iPSCs (78.3% vs 58.2% vs 47.9%). miPSCs, diPSCs and hiPSCs all expressed high levels of key endogenous pluripotency genes such as Oct4, Sox2 and Nanog, propagated robustly in single cell passaging and miPSCs were found to proliferated significantly faster than diPSCs and hiPSCs. Furthermore, miPSCs/MAFs clustered closer to diPSCs/DAFs than to hiPSCs/HAFs by RNA-seq. The establishment of miPSCs provide unique experimental materials for further investigation of understanding the “heterosis” and reproductive isolation during speciation. Comparative gene expression profiling analysis of RNA-seq data for mule,donkey and horse iPSCs and their respectively adult fibroblasts.