Simultaneous effects of IGF1 and Fadrozole on parthenogenesis and pluripotency markers in chicken embryo

So far, a synergistic effect was detected between insulin-like growth factor-I (IGF1) and anti-aromatase for sex reversal and pre-/post-natal growth of fertilized chicken embryo. Here, we hypothesized whether the growth and sexual female-to-male reversal effects of IGF1 and an anti-aromatase, Fadrozole, could improve the development of unfertilized, parthenogenetic chicken embryos. Simultaneous administration of IGF1 and Fadrozole increased the percentage of grade A embryos from 1.7% (no injection group) to 70.6%. The expression profile of parthenotes and newly laid fertilized embryos showed that IGF1 and Fadrozole increased SOX2 and NANOG expression, while decreased the TBX3 expression in the parthenogenetic embryos. However, a considerably higher expression of PRDM16, IGF2, NODAL and HDAC2 was observed in the fertilized group compared to the parthenogenetic embryos. In conclusion, chicken sexual determination is initiated at the earliest stage of embryonic development before gonadal differentiation. Combined administration of IGF1 and Fadrozole increased the developmental rate of parthenogenetic embryos. Also, simultaneous supplementation of IGF1 and Fadrozole induced the expression of pluripotency genes with no effect on the expression of growth and differentiation factors.