Development of a PCR Assay for Early Screening of Intersex Goats

Background: Intersex conditions are commonly observed in dioecious animals, particularly in goats, with a higher incidence in polled individuals. Understanding the phenotypic traits associated with intersex goats and developing effective screening methods are essential for early identification and genetic improvement in breeding programs. Methods: This study involved the collection of whole blood and gonadal tissues from 11 Chuanzhong Black goats (7 normal, 4 intersex), 6 Gulin Ma goats and 1 Tianfu goat (suspected intersex). Genomic DNA was extracted from jugular venous blood for molecular analysis and gonadal tissues were examined using hematoxylin-eosin staining. A multiplex PCR assay was developed to detect specific genetic variations linked to intersex conditions. Result: All four intersex Chuanzhong Black goats were polled (lacked horns) and exhibited abnormal external genitalia, classified as hermaphroditic, female-like, or male-like. These goats also showed signs of disordered coat condition, hair loss and dirty hindquarters. Both internal and external reproductive organs exhibited varying developmental defects. Molecular analysis revealed the absence of the Y chromosome and structural variations in the PIS region, including homozygous deletions and reverse-repeat insertions. The developed multiplex PCR assay effectively identified intersex individuals in the Chuanzhong Black, Gulin Ma and Tianfu goat breeds.