The significance of the X0 syndrome in infertility of the mare

Authors: Dewes HF, Blue MG, Bruere AN
Publication: New Zealand Veterinary Journal, Volume 26, Issue 6, pp 137-141, Jun 1978
Publisher: Taylor and Francis

Animal type: Horse, Livestock
Subject Terms: Congenital disease, Genetics, Diagnostic procedures, Reproduction, Oestrus/oestrous, Reproduction - female
Article class: Scientific Article

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Abstract: Analysis of mitotic chromosomes revealed the consistent lack of one sex chromosome in each of the four tissues studied from an infertile mare. Centromere staining of the chromosomes sex chromatin studies confirmed that this mare had the karyotype 63XO. Clinically this mare was small for her age and breed, exhibited intractable behaviour while at stud and was never observed in oestrus. Her genitalia appeared normal although uterus and ovaries were small and macroscopic follicles absent. Histologically, a number of presumptive atretic Graafian follicles and a discrete area of apparently functional luteal tissue were present in the right ovary. The significance of these findings is discussed and compared with the features of analogous syndromes associated with the XO anomaly in other species. It is
suggested that the XO anomaly in the horse may not always be
associated with complete sterility.

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