Genetic studies have shown that the dominant gene for polledness found in the Saanen breed will, when homozygous, lead to pscudohermaphrodism, testicular hypoplasia or cpididymal sperm granuloma and to an abnormal sex ratio (excess of males). An analysis of chromosomal constitution and nuclear appendages in peripheral leucocytes and tissue cultures of 17 pscudohermaphrodites, 10 males with epididymal sperm granuloma and 3 males with testicular hypoplasia was carried out. Sex chromatin could not be unequivocally distinguished in buccal or urinary bladder smears owing to the presence of other large chromatin masses. In no case was any trace of ovarian tissue found. One pseudohermaphrodite was a blood chimacra (XX/XY). This animal, a typical frcemartin, was indistinguishable in anatomy or histology from the other pseudohcrmaphrodites. The chromosomal constitution and nuclear appendages of the remaining 16 pseudohcrmaphrodites and of the males with testicular hypoplasia were those of a genetic female. It is concludcd that the pscudohermaphro- ditic effect of the polled gene is limited to genetic females and that males with testicular hypoplasia arc actually gcnetic females showing an extreme pseudo- hermaphroditic cffcct. The abnormal sex ratio characteristic of the Saanen breed is thus shown to be a trivial consequence of classifying extreme pscudohermaphrodites as males.The chromosomal constitution and nuclear appendages of the males with epididymal sperm granuloma were those of a normal male. Hence the gcnetic factor for polledness, when homozygous in genetic males, can lead to the development of epididymal sperm granuloma. © 1969 S. Karger AG, Basel.
