LIPIDOMICS AND MEMBRANE AQUAPORINS IN BOVINE SPERM
Date
2025-01-16
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
Type
Thesis
Degree Level
Doctoral
Abstract
Cryopreservation of bovine sperm leads to a significant reduction in post-thaw functionality, resulting in significant economic losses for the artificial insemination (AI) industry. Significant damage is inflicted on the sperm plasma membrane during this process. The current thesis investigated the relationship of sperm membrane aquaporins (AQP3 and AQP11) and lipidome in semen ejaculates of Bos taurus with sperm post-thaw motility (PTM). The first project localized and quantified both aquaporins using immunocytochemistry, western blotting and flow cytometry and correlated them with PTM. AQP3 was localized in the acrosomal region, whereas AQP11 was in the sperm tail with diffused localization in the sperm head. Both aquaporins showed positive correlations with PTM based on flow cytometry analysis, suggesting their potential as biomarkers for sperm PTM. The second project explored the lipid composition of bovine sperm, identifying 263 lipid species across 11 lipid classes. Phosphatidylcholine (PC), phosphatidylethanolamine (PE) and total lipid class content showed positive, while lyso-PC and glucosylceramide (GlcCer) showed negative correlations with PTM. The final project explored individual lipid expression in high and low PTM bull groups using a number of statistical methods. This study found that PC- and PE-conjugated polyunsaturated long-chain fatty acids were dominant in sperm lipids from high PTM bulls and may serve as biomarkers for PTM. On the contrary, most sphingomyelin (SM) and phosphatidylglycerol (PG) species were dominant in sperm lipids from low PTM bulls. This research may contribute to developing pre-freeze viability assays, lipid-based diets and modified extenders to improve sperm post-thaw survival by the AI industry.
Description
Keywords
Cryopreservation, bovine, sperm, aquaporins, lipidomics, artificial insemination
Citation
Degree
Doctor of Philosophy (Ph.D.)
Department
Biology
Program
Biology