Related Experiment Videos
A novel apical midpiece defect in the spermatozoa of a bull without an apparent decrease in motility and fertility. A
A Rocha1, E Oliveira, M J Vilhena
1ICBAS, Abel Salazar Biomedical Institute, University of Porto, Portugal. arocha@mail.icav.up.pt
Theriogenology
|March 28, 2006
Summary
A novel sperm defect in Charolais bulls, affecting mitochondrial and outer dense fiber structure, was observed without impacting fertility. This finding is crucial for understanding sperm viability in artificial insemination programs.
Area of Science:
- Veterinary Reproduction
- Sperm Biology
- Animal Breeding
Background:
- Sperm morphology and motility are common metrics for assessing frozen/thawed semen viability.
- Artificial insemination (AI) programs rely on high-quality semen for successful outcomes.
Observation:
- A novel midpiece structural defect was identified in 24-36% of frozen/thawed Charolais bull sperm.
- The defect involved mitochondrial aplasia, elongation, and alterations in outer dense fibers and plasma membrane in the midpiece.
Findings:
- Despite the observed defect, sperm progressive motility (65-80%) and pregnancy rates (43%) were comparable to control bulls (40%).
- No abnormalities were found in other sperm structures like the axoneme, annulus, or fibrous sheath.
- The defect is hypothesized to originate from the loss of cementing substance linking mitochondria to the plasma membrane.
Implications:
- This sperm defect does not appear to compromise fertility in the studied Charolais bull.
- Understanding such defects is vital for refining semen evaluation protocols in AI.
- Further research may clarify the specific etiological factors and potential genetic links to this abnormality.