title: Mammalian freeze-dried sperm can maintain their calcium oscillation-inducing ability when microinjected into mouse eggs.
abstract: Mammalian freeze-dried sperm can maintain their genetic integrity and event support full development to term when microinjected into mature oocytes. However, it is unknown whether freeze-dried sperm can still maintain their calcium oscillation-inducing capability. Here, we microinjected mouse and bovine freeze-dried sperm into mouse MII oocytes and examined their calcium oscillation-inducing ability following intracytoplasmic sperm injection (ICSI). Two pieces of information are revealed. First, nearly all oocytes injected with a freeze-dried mouse sperm head or a bovine sperm showed fertilization-like calcium oscillations, indicating that freeze-drying treatment does not affect the activity of the sperm factor responsible for calcium oscillations. Second, freeze-dried sperm exhibited high resistance to external temperature increase. This is shown by the finding that the freeze-dried sperm can maintain their calcium oscillation-inducing capacity even following exposure to 100 degrees C for 3 h. We therefore conclude that mammalian sperm can maintain their calcium oscillation-inducing capability following freeze-drying, rehydration, and ICSI treatments.
authors.affiliation: Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100080, People's Republic of China.
authors.forename: Qi-Cai
authors.initials: QC
authors.lastname: Liu
authors.forename: Tian-e
authors.initials: TE
authors.lastname: Chen
authors.forename: Xiu-Ying
authors.initials: XY
authors.lastname: Huang
authors.forename: Fang-Zhen
authors.initials: FZ
authors.lastname: Sun
mesh_terms: D000818:Animals; D020013:Calcium Signaling / Q000502:physiology*; D002417:Cattle; D002460:Cell Line; D002478:Cells, Cultured; D015925:Cryopreservation / Q000379:methods*; D008297:Male; D051379:Mice; D008845:Microinjections; D009865:Oocytes / Q000502:physiology*; D012662:Semen Preservation / Q000379:methods*; D020554:Sperm Injections, Intracytoplasmic / Q000379:methods*; D013094:Spermatozoa / Q000378:metabolism* / Q000637:transplantation*