[Intersexuality in horses].

The research article is a study conducted over five years, investigating intersexuality in horses using various diagnostic methods, including cytogenetic, molecular genetic, histopathological and endocrinological. Ten horses with reduced fertility or suspected intersexuality were examined, revealing several abnormalities in their reproductive systems.

Cytogenetic, Molecular Genetic, Histopathological and Endocrinological Methods

• The research used a range of methods to investigate intersexuality in horses.
• The cytogenetic method was used to study the number and appearance of chromosomes, the structures containing the horse’s genetic information.
• Molecular genetic techniques were utilised to investigate the aspects of DNA itself, such as identifying gene mutations or deletions.
• Endocrinological methods deal with hormone functioning, which is crucial to the development of sexual characteristics in horses.
• Lastly, histopathological methods were used to examine horse tissues under the microscope, in particular the tissues from the reproductive system.

Findings of the Study

• The study revealed that one of the horses had a 64,XX/63,X0 mosaicism, a rare chromosomal disorder where some cells have 64 chromosomes while others only have 63. This condition can cause developmental and sexual abnormalities.
• Six cases were identified with male pseudohermaphroditism, where the horse has a male karyotype (the number, size, and shape of chromosomes in the cell nucleus), but also contains rudimentary parts of a female reproductive system.
• One horse was suspected to have XX-sex reversal syndrome, which is characterized by female chromosomal constitution with the presence of a uterus and parts of a vagina, but also testes tissue.
• Lastly, another horse was likely affected by SRY-negative XY-sex reversal syndrome, which is where parts of a female reproductive tract are present, but no testes tissue is present. The cause for this syndrome was suspected to be due to a deletion of the SRY gene, crucial for male sex determination.

Conclusion

• The study offers a comprehensive investigation into intersexuality in horses, a complex condition affecting their reproductive system.
• Encountering such cases pose difficulties in diagnosis due to the subtle changes or abnormalities in the horses’ reproductive tracts. However, through a variety of diagnostic methods, the researchers were able to uncover the diverse nature of intersexuality disorders in horses.