Numerical sex chromosome aberrations and abnormal sex development in horse and sheep.
Gonadal dysgenesis and heterosexual conditions are often associated with sex chromosome abnormalities. In this study we report on 2 cases of abnormal sex development involving numerical sex chromosome aberrations in both horse and sheep. A 17-month-old Standardbred filly was sent to an equine fertility centre as an embryo donor due to its reduced size, being much smaller than a racehorse filly of the same age, which excluded it from an athletic career. External genitalia were clinically normal but manual palpation of the reproductive tract showed the presence of a small underdeveloped uterus and ovaries, as confirmed by ultrasonographic examination. Cytogenetic investigation by CBA-banding revealed an abnormal karyotype with X chromosome monosomy (2n = 63,X). A 18-month-old ewe showed distinct heterosexual traits with presence of a vulva (with enlarged clitoris), well-developed abdominal testes and mammary glands. Internal sex adducts were atrophic as seen after mating. Cytogenetic analysis revealed the presence of XX/XY mosaicism.
Di Meo
G P
GP
National Research Council, ISPAAM, Laboratory of Animal Cytogenetics and Gene Mapping, Naples, Italy.
Neglia
G
G
Perucatti
A
A
Genualdo
V
V
Iannuzzi
A
A
Crocco
D
D
Incarnato
D
D
Romano
G
G
Parma
P
P
Iannuzzi
L
L
D000818:Animals; D002871:Chromosome Banding; D012734:Disorders of Sex Development / Q000235:genetics / Q000662:veterinary*; D005260:Female; D006736:Horses / Q000002:abnormalities* / Q000235:genetics*; D008297:Male; D008677:Metaphase; D012729:Sex Chromosome Aberrations; D012726:Sexual Behavior, Animal; D012756:Sheep / Q000002:abnormalities* / Q000235:genetics*