DNA polymorphism analysis of hereditary multiple exostoses in horses.

Genomic DNA polymorphisms obtained by restriction fragment-length polymorphism from healthy horses and horses with hereditary multiple exostoses were analyzed. These DNA were digested by 12 restriction enzymes and were hybridized against 6 isotopically labeled oncogene probes. Hybridization was not detected with the viral oncogene, v-ras, which indicated this oncogene was absent in the equine genome. Oncogenes (c-raf-1, c-fes, c-myb, c-myc, and c-sis) were present and had similar hybridization patterns and signal intensities in DNA from healthy horses and horses with hereditary multiple exostoses. Unique and distinct restriction fragment-length polymorphisms were detected with the c-raf-1 probe only in BamHI- and PstI-digested equine DNA.