A male to female sex-reversed dog with a reciprocal translocation.
A registered female Yorkshire terrier aged 3 years was diagnosed as intersex. Molecular and cytogenetic studies were carried out to determine whether chromosomal abnormalities were involved in the development of this condition. Analysis of the testicular tissue in the gonads and PCR amplification of three canine Y chromosome-specific DNA sequences from the genomic DNA of this animal indicated that the dog had a genetic complement with a Y chromosome. An analysis of > 100 banded metaphase chromosome spreads of this intersex dog showed uniformly a 78,XY chromosome complement and confirmed that the animal might be a male to female sex-reversed dog. However, two different types of X chromosome were observed. A whole chromosome painting probe was developed by microdissection of ten X chromosomes from the intersex dog and used for fluorescence in situ hybridization experiments on metaphase chromosome spreads from a normal male dog. Hybridization signals were detected on the X chromosome and on an autosome (not yet internationally standardized) indicating that a reciprocal translocation event had occurred. The karyotype of this mosaic sex-reversed dog was designated tentatively as 78,XY/78,XYrcp (X; autosome). This is believed to be the first report of a canine intersex dog showing male to female sex reversal. Further investigations should identify the autosome and the breaking points of the chromosomal rearrangement. These investigations potentially add to our knowledge of autosomal and X-linked loci involved in sexual differentiation of mammals.
Schelling
C
C
Department of Animal Science, Swiss Federal Institute of Technology, Tannenstrasse 1, CH-8092 Zürich, Switzerland.
Pieńkowska
A
A
Arnold
S
S
Hauser
B
B
Switoński
M
M
D000818:Animals; D012734:Disorders of Sex Development; D004285:Dogs / Q000235:genetics*; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008297:Male; D014178:Translocation, Genetic; D014960:X Chromosome