A HORSE CHROMOSOME-ARM-SPECIFIC PROBE COLLECTION FOR FLUORESCENCE IN SITU HYBRIDIZATION STUDIES.

¹ Genetics Section Animal Health Trust Lanwades Park Kentford Suffolk CB8 7UU U.K.

² Department of Veterinary Science M.H. Gluck Equine Research Center University of Kentucky Lexington, KY 40546-0099 USA

The horse has a diploid chromosome number of 64 comprising 13 pairs of metacentric/ submetacentric autosomes, 18 pairs of acrocentric autosomes and a metacentric X chromosome and submetacentric Y chromosome. As part of the International Equine Gene Mapping Workshop a revised international system for cytogenetic nomenclature of the domestic horse was produced in 1996, by the Third International Committee for the Standardisation of the Domestic Horse Karyotype. This publication provides a basis for the identification of all horse chromosomes, based on their G- and R-banded appearance. To facilitate the rapid identification of each horse chromosome in fluorescence in situ hybridization (FISH) studies, a complete collection of chromosome-arm specific probes has been collated from laboratories who participate in the International Equine Gene Mapping Workshop. Each of the selected probes has been demonstrated to give a strong, specific signal on the corresponding chromosome, with a positional bias towards the distal end of each chromosome arm. Complete sets of probe DNA samples will be made available to interested parties.