title: Effect of trehalose on DNA integrity of freeze-dried boar sperm, fertilization, and embryo development after intracytoplasmic sperm injection.
abstract: Freeze-drying (FD) medium containing ethylene glycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) is reported to be beneficial for maintenance of sperm DNA integrity after FD. Recently, trehalose has also been reported to have notable ability to stabilize the protein structure and biomembranes of sperm in a dry state. In this study, we examined the effect of a combination of EGTA and different concentrations of trehalose in FD medium on sperm DNA integrity and the in vitro development of IVM porcine oocytes after intracytoplasmic sperm injection (ICSI) using freeze-dried boar sperm. Ejaculated sperm from a boar were suspended in basic FD medium supplemented with 0, 3.75, 7.5, 15, 30, 60, or 90 mM trehalose and freeze-dried. After rehydration, the sperm in all groups were subjected to DNA damage detection using a Halomax kit. It was found that the level of DNA damage in 15-mM group was significantly lower than that in 0-mM group, and no difference was observed between the 15-, 7.5-, and 3.75-mM groups. Moreover, there were no significant differences in the DNA damage level among 0, 3.75 mM, and other groups treated with trehalose. When freeze-dried sperm were used for ICSI, the fertilization rates and blastocyst formation rates (observed at 10 hours and 6 days of IVC after ICSI, respectively) in the 7.5- and 15-mM groups were not different from those in 0-mM group. These results suggest that FD medium supplemented with trehalose at appropriate concentrations improves sperm DNA integrity, but does not improve fertilization and preimplantation embryo development of IVM oocytes following ICSI.
authors.affiliation: Division of Animal Sciences, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan; Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan; Laboratory of Embryo Technology, Institute of Biotechnology, Vietnam Academy of Science and Technology, Hanoi, Vietnam.
authors.forename: Nguyen Thi
authors.initials: NT
authors.lastname: Men
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kikuchi
authors.forename: Michiko
authors.initials: M
authors.lastname: Nakai
authors.forename: Atsunori
authors.initials: A
authors.lastname: Fukuda
authors.forename: Fuminori
authors.initials: F
authors.lastname: Tanihara
authors.forename: Junko
authors.initials: J
authors.lastname: Noguchi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kaneko
authors.forename: Nguyen Viet
authors.initials: NV
authors.lastname: Linh
authors.forename: Bui Xuan
authors.initials: BX
authors.lastname: Nguyen
authors.forename: Takashi
authors.initials: T
authors.lastname: Nagai
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tajima
mesh_terms: D000818:Animals; D053903:DNA Breaks, Double-Stranded; D047108:Embryonic Development / Q000187:drug effects*; D005306:Fertilization / Q000187:drug effects*; D005612:Freeze Drying / Q000379:methods / Q000662:veterinary*; D008297:Male; D020554:Sperm Injections, Intracytoplasmic / Q000662:veterinary; D013094:Spermatozoa / Q000187:drug effects* / Q000502:physiology; D013552:Swine; D014199:Trehalose / Q000494:pharmacology*
chemical_list: D014199:Trehalose
keywords: DNA fragmentation; Freeze-drying; ICSI; Pig; Trehalose