title: Improving sperm cryopreservation with antifreeze proteins: effect on gilthead seabream (Sparus aurata) plasma membrane lipids.
abstract: Changes in the plasma membrane lipid composition have been related to a decrease in sperm quality during cryopreservation. Antifreeze proteins (AFPs) have been tested in different species because of their ability to depress the freezing point and their potential interaction with membranes, but controversial effects were reported. In the present study we analyzed separately the lipid composition of two sperm membrane domains, head plasma membrane (HM) and flagellar membrane (FM), after cryopreservation with an extender containing 5% dimethyl sulfoxide (DMSO) either alone or with AFPI or AFPIII (1 μg/ml). We used sperm from a teleost, Sparus aurata, because the lack of acrosome avoids changes of lipid profiles due to capacitation process or acrosomal losses during freezing/thawing. Comparing with the control (cryopreservation with 5% DMSO alone), the addition of AFPIII increased the velocity, linearity of movement, and percentage of viable cells. In addition, freezing with DMSO alone increased the phosphatidyl-serine content as well as the saturated fatty acids and decreased the unsaturated ones (mainly polyunsaturated) both in HM and FM. These changes in the lipid components were highly avoided with the addition of AFPIII. HM had a higher amount of saturated fatty acids than FM and was more affected by cryopreservation without AFPs. The percentage of viable cells was positively correlated with the amount of unsaturated fatty acids in the HM, whereas the motility parameters were positively correlated with both FM and HM amount of unsaturated fatty acids. AFPs, especially AFPIII, seem to have interacted with unsaturated fatty acids, stabilizing the plasma membrane organization during cryopreservation and contributing to improve sperm quality after thawing.
authors.affiliation: Department of Molecular Biology, Faculty of Biology, University of León, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Beirão
authors.forename: Loredana
authors.initials: L
authors.lastname: Zilli
authors.forename: Sebastiano
authors.initials: S
authors.lastname: Vilella
authors.forename: Elsa
authors.initials: E
authors.lastname: Cabrita
authors.forename: Roberta
authors.initials: R
authors.lastname: Schiavone
authors.forename: Maria Paz
authors.initials: MP
authors.lastname: Herráez
mesh_terms: D000818:Animals; D021301:Antifreeze Proteins / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects* / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology*; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D005227:Fatty Acids / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D008297:Male; D008563:Membrane Lipids / Q000378:metabolism*; D010473:Perciformes / Q000378:metabolism*; D012662:Semen Preservation / Q000379:methods*; D013077:Sperm Head / Q000187:drug effects / Q000648:ultrastructure; D013082:Sperm Tail / Q000187:drug effects / Q000648:ultrastructure
chemical_list: D021301:Antifreeze Proteins; D003451:Cryoprotective Agents; D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D008563:Membrane Lipids; D004121:Dimethyl Sulfoxide