title: A study on freeze-drying as a method of preserving mouse sperm.
abstract: This review describes the study of freeze-dried mouse sperm for practical application in preserving and transporting genetic resources. Freeze-dried sperm can be used to preserve and transport genetic resources; however, there still remain many areas which need to be studied. In particular, it is essential to assure long-term preservation over several decades or centuries. Recently, the theory of accelerated degradation kinetics to freeze-dried mouse sperm has been applied, and found that long-term preservation by conventional methods requires temperatures lower than -80 C. When the relationship between the pressure at primary drying and the preservation potential of freeze-dried mouse sperm was examined, a pressure of 0.37 mbar at primary drying significantly improved the developmental rate to the blastocyst stage. In addition, it has been shown that freeze-dried sperm stored at -80 C with and without transportation can retain their ability to generate viable offspring after storage for up to 2 years. Sperm chromatin structure assay (SCSA) was applied to mouse sperm freeze-dried under several conditions and compared the results with the embryonic developmental rates of freeze-dried sperm after intracytoplasmic sperm injection (ICSI) and with comet assay results. Furthermore, SCSA might be useful for estimation of developmental potential of fertilized eggs derived from ICSI using freeze-dried sperm in mice.
authors.affiliation: Chugai Research Institute for Medical Science, Inc., Gotemba, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Kawase
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Suzuki
mesh_terms: D000818:Animals; D020552:Comet Assay; D015925:Cryopreservation / Q000379:methods*; D053938:DNA Fragmentation; D005612:Freeze Drying; D008297:Male; D051379:Mice; D011312:Pressure; D012098:Reproduction; D013094:Spermatozoa