Molecular characterization of the equine testis-specific protein 1 (TPX1) and acidic epididymal glycoprotein 2 (AEG2) genes encoding members of the cysteine-rich secretory protein (CRISP) family.

The research focused on studying key genes related to male fertility in horses, namely the Testis-specific protein 1 (TPX1) and Acidic epididymal glycoprotein 2 (AEG2), which are part of the Cysteine-rich secretory protein (CRISP) family. The research uncovered the cloning and DNA sequence of these genes and investigated their expression in a variety of tissues.

Focus on the Genes of the CRISP Family

• CRISP family comprises three members: AEG1, AEG2, and TPX1.
• These genes are encoded primarily in different segments of the male genital tract, where they potentially mediate interactions between male germ cells and other cells during sperm maturation or fertilization.
• Given their role, these genes have been of notable interest in studying inherited male fertility dysfunctions and male fertility traits quantitatively.

Investigation and Characterization of TPX1 and AEG2

• The research peers into the DNA cloning and sequencing for TPX1 and AEG2 genes found in equine chromosome 20q22, within 137 kb of horse genomic DNA.
• The TPX1 gene was found to have ten exons spanning over 18 kb, while the AEG2 gene had eight exons spreading across 24 kb.
• Researchers conducted reverse transcription polymerase chain reaction analysis and Western blotting to examine the expression of these genes in various tissues.

Findings and Conclusion

• The comparative genome analysis across the horse, human, and mouse showed that all three CRISP genes are grouped together on a single chromosomal location.
• This revealed a conserved synteny or co-localization of these genes on the same chromosome segment across these species.
• This study has provided more insight into the genetic basis of male fertility potential, with possible implications for both animal breeding and human fertility treatments.