G-band identification of the chromosomes of sheep.

Peripheral blood cultures were made on 20 Dorset sheep including 16 ewes and 4 rams. Photomicrographs of 100 cells were examined for trypsin-induced G-bands, and the length of each chromosome was measured. The banding patterns of each of the 27 pairs of chromosomes were identified and described, and the results observed in this study were compared with those previously reported. Measurements of all chromosomes in which both members of a homologous pair were identifiable were used to calculate mean relative length. Karyotypes, in which chromosomes were arranged to mean relative length, were prepared and an idiogram illustrating major bands was constructed.