The Journal of Heredity 1988:79(4):311-313
© 1988 The American Genetic Association 79:311-313
research-article |
Y Chromosome Length Variation and its Significance in the Horse
Medical Genetics Division, Department of Pathology, University College Dublin Ireland
Address reprint requests to Dr Power, Medical Genetics Division, Department of Pathology, University College Dublin, Earlsfort Terrace, Dublin 2, Ireland.
Abstract
The results of Y chromosome measurements in 31 horses are presented The Y chromosomewas identified using G-, R-, and C-banding techniques. From G-banded metaphase spreads, total X and Y chromosome and separate proximal (P) and distal (D) Y-band measurements were made. Within this group, the Y/X ratio (%) for each animal varied from 18.93 to 43.95, with an overall mean of 34.85 and a coefficient of variation (CV) of 16.12. The overall mean P/X ratio (%) was 23.57 with a CV of 20.57, compared with an overall mean D/X ratio (%) of 11.26 with a CV of 15.18. The group studied included 27 Thoroughbred and 4 non-Thoroughbred animals, of which 20 were clinically normal controls and 11 presented with various clinical abnormalities. By comparison with data from other species, the possible breed association and clinical significance of the observed heteromorphism for the Y chromosome in this species is discussed.