The Phospholipid Composition of Kangaroo Spermatozoa Verified by Mass Spectrometric Lipid Analysis

Abstract

Cryopreservation of kangaroo sperm has not been successful so far, and yet there is no promising cryopreservation protocol for these cells available. However, conservation of gametes is extremely important, particularly in the context of preserving endangered species. As spermatozoa are comprised of different membrane systems, the composition of these membranes might account for difficulties in cryopreservation. Lipids, as the main components, affect the physical properties of biological membranes and play a major role in sperm maturation. Therefore, knowledge of the lipid composition is crucial for any further step toward the preservation of the species. We used MALDI-TOF, ESI-IT, tandem mass spectrometry, and thin layer chromatography to investigate the lipid composition of epididymal spermatozoa of four different kangaroo species. Spectra of these species were very similar with respect to the identified lipid species. Tremendous changes in the lipid composition during the transit of sperm from caput to cauda epididymis could be seen, specifically an increase in poly-unsaturated fatty acids, ether lipids, and plasmalogens, as well as a reduction in mono- and di-unsaturated fatty acids. Additionally, phosphatidylcholines containing docosatrienoic acid (22:3), a heretofore unknown fatty acid for sperm membranes, showed the highest abundance in kangaroo sperm.

Alteration of Cholesterol Sulfate/Seminolipid Ratio in Semen Lipid Profile of Men With Oligoasthenozoospermia

“…Both lipids are visible in the three lipid profiles. The Chol-S is more abundant in the lipid profile of seminal plasma, whereas SGG in that of spermatozoa, as previously described (Schiller et al, 2000; Lessig et al, 2004; Engel et al, 2017).…”

The repertoire of Adhesion G protein-coupled receptors in adipocytes and their functional relevance

“…Lipid extraction was performed according to Matyash et al [50] and HPTLC and ESI-IT MS measurements according to Engel et al [51]. TAG fractions were independently investigated by GC analysis performed as already essentially described [52,53].…”

Metabolomic profiling reveals correlations between spermiogram parameters and the metabolites present in human spermatozoa and seminal plasma

“…In human sperm, 42 and 27 metabolites have been identified by untargeted approaches using nuclear magnetic resonance (NMR) spectroscopy and gas chromatography coupled to mass spectrometry (GC-MS), respectively [7]. MS-based methods were also used to characterize the lipid composition of sperm and seminal plasma from different species [8–10]. However, to the authors’ best knowledge, a targeted approach to identify metabolites present in sperm and seminal plasma obtained from the same donors by liquid chromatography (LC) and the determination of the correlation of the levels of these metabolites in both types of specimens with manually assessed spermiogram parameters have not yet been reported.…”