A gene catalogue of the euchromatic male-specific region of the horse Y chromosome: comparison with human and other mammals.
Authors: Paria Nandina, Raudsepp Terje, Pearks Wilkerson Alison J, O'Brien Patricia C M, Ferguson-Smith Malcom A, Love Charles C, Arnold Carolyn, Rakestraw Peter, Murphy William J, Chowdhary Bhanu P
Journal: PloS one
Summary
# Editorial Summary Understanding male fertility at the genetic level has long relied on research in primates, rodents and carnivores, yet the male-specific region of the Y chromosome (MSY) varies considerably between species, making it difficult to identify which genes actually control fertility in horses specifically. Nandina and colleagues catalogued 37 genes on the horse Y chromosome using cDNA selection from testis tissue combined with sequencing analysis, then compared these genes against other mammals to distinguish which ones were conserved across species and which were unique to equines. Twenty genes matched orthologs found in other mammals, whilst 17 were either novel to horses or shared only with donkeys, with notably different organisational patterns compared to human and carnivore Y chromosomes. Critically, 10 multicopy genes showed testis-specific expression and emerge as promising candidates for stallion fertility, providing a foundation for investigating Y-linked infertility problems in breeding stock. For equine practitioners involved in reproductive management and breeding decisions, this work opens the possibility of future genetic screening for stallion subfertility and establishes the biological framework necessary to understand inherited male reproductive disorders in horses.
Read the full abstract on PubMed
Practical Takeaways
- •Genetic markers for stallion fertility assessment may be identified through the 10 multicopy testis-specific genes on the Y chromosome
- •Understanding horse-specific Y chromosome genes could help diagnose genetic causes of subfertility or infertility in individual stallions
- •This foundational gene catalogue enables future breeding programs to select for genetic factors associated with male fertility traits
Key Findings
- •Horse Y chromosome contains 37 identified MSY genes, including 20 X-degenerate genes conserved across eutherian mammals and 17 novel genes unique to equine or equine-donkey lineages
- •10 multicopy genes with testis-specific expression identified as candidate genes for stallion fertility
- •Horse MSY gene functions predominantly relate to testis function and spermatogenesis, consistent with other mammalian species despite substantial sequence and organizational differences