RNA sequencing analysis of blastoderms of chickens (Gallus gallus), quails (Coturnix japonica), and their F1 hybrids.

Hybrid dysgenesis is important for the maintenance of species identity and promotion of speciation. However, the genetic basis for hybrid dysgenesis remains largely unknown. Chickens (2n =78) and Quails (2n=78) are classified into different genera of the Phasianidae family, but their F1 hybrids can be produced by artificial insemination. In F1 hybrid fertilized eggs, most of embryos die before hatching, and only males can hatch, i.e., hybrid dysgenesis is prominent in the heterogametic ZW females, which corresponds to Haldane's rule. In the present study, to search into the genetic basis of hybrid dysgenesis of chicken-quail intergeneric F1 hybrids, we performed RNA sequencing analysis of the blastoderms (EGK stages X and XIII/XIV) of chickens, quails, and their F1 hybrids, and compared the gene expressions between hybrids and the parental species.