title: Metabolic incorporation of unsaturated fatty acids into boar spermatozoa lipids and de novo formation of diacylglycerols.
abstract: Lipids play an important role in the maturation, viability and function of sperm cells. In this study, we examined the neutral and polar lipid composition of boar spermatozoa by thin-layer chromatography/mass spectrometry. Main representatives of the neutral lipid classes were diacylglycerols containing saturated (myristoyl, palmitoyl and stearoyl) fatty acyl residues. Glycerophosphatidylcholine and glycerophosphatidylethanolamine with alk(en)yl ether residues in the sn-1 position and unsaturated long chained fatty acyl residues in sn-2 position were identified as the most prominent polar lipids. The only glycoglycerolipid was sulfogalactosylglycerolipid carrying 16:0-alkyl- and 16:0-acyl chains. Using stable isotope-labelling, the metabolic incorporation of exogenously supplied fatty acids was analysed. Boar spermatozoa incorporated hexadecenoic (16:1), octadecenoic (18:1), octadecadienoic (18:2) and octadecatrienoic (18:3) acids primarily in the diacylglycerols and glycerophosphatidylcholines. In contrast, incorporation of eicosapentaenoic acid (20:5) was not detected. The analysis of molecular species composition subsequent to the incorporation of exogenous [(14)C]-octadecadienoic acid suggests two pathways for incorporation of exogenous fatty acids into glycerophosphatidylcholine: (1) de novo synthesis of glycerophosphatidylcholine via the CDP-choline pathway and (2) reacylation of lysophosphatidylcholine via an acyltransferase.
authors.affiliation: Institute for Reproduction of Farm Animals Schönow e.V., Bernauer Allee 10, D-16321 Bernau, Germany; Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Str. 17, D-10315 Berlin, Germany.
authors.forename: Valentin
authors.initials: V
authors.lastname: Svetlichnyy
authors.affiliation: Humboldt-University Berlin, Department of Biology, Invalidenstr. 42, D-10115 Berlin, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Müller
authors.affiliation: University of Copenhagen, Department of Plant and Environmental Sciences, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark.
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Pomorski
authors.affiliation: Institute for Reproduction of Farm Animals Schönow e.V., Bernauer Allee 10, D-16321 Bernau, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Schulze
authors.affiliation: University of Leipzig, Department of Medical Physics and Biophysics, Härtelstr. 16-18, D-04107 Leipzig, Germany. Electronic address: juergen.schiller@medizin.uni-leipzig.de.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Schiller
authors.affiliation: Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Str. 17, D-10315 Berlin, Germany. Electronic address: mueller@izw-berlin.de.
authors.forename: Karin
authors.initials: K
authors.lastname: Müller
mesh_terms: D000818:Animals; D004075:Diglycerides / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism*; D019281:Dimerization; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D008297:Male; D013094:Spermatozoa / Q000378:metabolism*; D034421:Sus scrofa
chemical_list: D004075:Diglycerides; D005231:Fatty Acids, Unsaturated; C027369:octadecadienoic acid
keywords: AA; BTS; Beltsville Thawing Solution; Boar spermatozoa; DAG; DHB; Diacylglycerol; FFA; Fatty acid; GC; GPA; GPC; GPE; GPI; GPL; GPS; Glycerophospholipid; LPC; MAG; MS; PLA(2); PLC; SGG; TLC; aminoacridine; diacylglycerol; dihydroxybenzoic acid; free fatty acids; gas chromatography; glycerophosphatidic acid; glycerophosphatidylcholine; glycerophosphatidylethanolamine; glycerophosphatidylinositol; glycerophosphatidylserine; glycerophospholipid; lyso-glycerophosphatidylcholine (monoacylglycerophosphatidylcholine); mass spectrometry; monoacylglycerol; phospholipase A(2); phospholipase C; sulfogalactosylglycerolipid; thin-layer chromatography