Skeletal development in blue-breasted quail embryos.

The blue-breasted quail (Coturnix chinensis), the smallest species of quail with short generation interval and excellent reproductive performance, is a potential avian research model. A normal series of skeletal development of avian embryos could be served as a reference standard in the fields of developmental biology and teratological testing as well as in the investigation of mutation with skeletal abnormalities and in the study of the molecular mechanisms of skeletal development through genome manipulation. Furthermore, ossification sequence shows a species-specific pattern and has potential utility in phylogeny. However, data on the skeletal development of blue-breasted quail embryos are scarce. Here, we established a series of normal stages for the skeletal development of blue-breasted quail embryos. Cartilage and ossified bones of blue-breasted quail embryos were stained blue and red with Alcian blue 8GX and Alizarin red S, respectively. The time and order of chondrification and calcification of their skeletons were documented every 24 hr from 3 to 17 days of incubation, and a 15-stage series of skeletal development was created. Moreover, a comparative study with the Japanese quail (Coturnix japonica) demonstrated that ossification sequence differed significantly between these two species.