An equine cryptorchid with testicular and ovarian tissues.
Cytogenetic and histological studies were carried out on an intersex horse which was diagnosed clinically as a cryptorchid. Surgery confirmed the horse to be a bilateral abdominal cryptorchid and histological examination revealed ovarian tissue associated with the left epididymis. Chromosome analysis of cultured cells from testicular tissue, ovarian tissue and skin revealed 64-XX and 64-XY make-up, the left gonad containing a greater preponderance of XX cells over XY cells. The external characteristics and behaviour of the horse were indistinguishable from that of a "routine" cryptorchid. Other cases of equine intersexes are reviewed and theories for the discrepancies between genetic, gonadal and phenotypic sex are discussed.
D000818:Animals; D003456:Cryptorchidism / Q000235:genetics / Q000473:pathology / Q000662:veterinary*; D012734:Disorders of Sex Development / Q000235:genetics / Q000662:veterinary*; D005260:Female; D006734:Horse Diseases / Q000235:genetics / Q000473:pathology*; D006736:Horses; D008297:Male; D010053:Ovary / Q000648:ultrastructure*; D013737:Testis / Q000648:ultrastructure*