Detailed Description and Nomenclature of High Resolution G-Banded Horse Chromosomes and Cytogenetic Analysis of Hereditary Multiple Exostosis in Horses

A reliable technique for obtaining late prophase, prometaphase and greater numbers of metaphase chromosomes is presented. The increased number of mitoses and high resolution chromosomes were obtained using a modification of the typical three-day blood culture technique in which the cell cycle was temporarily blocked at the G1-s border with methotrexate. A high resolution G-band idiogram is presented using a system similar to the standardization of human chromosomes. The use of this technique and system of nomenclature will facilitate routine analyses of horse chromosomes and provide a basis for the identification and recording of chromosome aberrations in this species. C-bands and NORs of the domestic horse are also described. C-bands, NORs and high resolution G-bands of control horses were compared with those of horses affected with Hereditary Multiple Exostosis. No differences were found on NORs, C- and G-bands between control and exostosis horses