Reprogramming efficiency and pluripotency of mule iPSCs over its parents†.

Abstract

The mule is the interspecific hybrid of horse and donkey and has hybrid vigour in muscular endurance, disease resistance and longevity over its parents. Here, we examined adult fibroblasts of mule (MAFs) compared with the cells from their parents (DAFs and HAFs) (each species have repeated three independent individuals) in proliferation, apoptosis and glycolysis and found significant differences. We subsequently derived mule, donkey and horse induced pluripotent stem cells (miPSCs, diPSCs and hiPSCs) from three independent individuals of each species and found the reprogramming efficiency of MAFs were significantly higher than that of cells of donkey and horse. miPSCs, diPSCs and hiPSCs all expressed high levels of crucial endogenous pluripotency genes such as POU class 5 homeobox 1 (POU5F1, OCT4), SRY-box 2 (SOX2) and Nanog homeobox (NANOG) and propagated robustly in single cell passaging. miPSCs exhibited faster proliferation and higher pluripotency and differentiation than diPSCs and hiPSCs, which were reflected in co-cultures and separate-cultures, teratoma formation and chimera contribution. The establishment of miPSCs provide unique research material for investigation of "heterosis" and perhaps is more significant to study hybrid gamete formation.