Culture System for Bobwhite Quail Embryos from the Blastoderm Stage to Hatching

Quail are divided phylogenetically into two groups, Old World quail and New World quail. Old World quail, such as the Japanese quail (Coturnix japonica), belong to the Phasianidae and distributed in the Palaearctic region (Europe, North Africa, and Asia), whereas New World quail, such as the bobwhite quail (Colinus virginianus), belong to the Odontophoridae and are restricted to North and South America. Both the bobwhite quail and the Japanese quail are used as models for avian safety assessment as recommended by the Organisation for Economic Co-operation and Development (OECD) guidelines. However, biological studies on the bobwhite quail have been limited compared with those on the Japanese quail. We have therefore now developed an ex vivo culture protocol for bobwhite quail embryos from the blastoderm stage through hatching. Of the various culture conditions examined in the present study, a good hatching rate (39%) was obtained when the embryos were cultured ex vivo in a two-step procedure. Unincubated embryos (with egg yolk) were first cultured inside the shell of a Japanese quail eggs (11.5 to 13.0 g whole egg weight) together with chicken thin albumen for 63 to 65 h and were then transferred to the shell of a small-sized chicken egg (38 g whole egg weight) until hatching. This ex vivo culture system should provide to be widely applicable to the maintenance and generation of manipulated birds for basic and applied studies on the bobwhite quail.