Kaoruko Mizuno1, Kazuhiko Hoshi, Thomas Huang. 1. Kapiolani Medical Center, Department of Obstetrics and Gynecology, University of Hawaii School of Medicine, Honolulu, HI 96826, USA. kmizuno@res.yamanashi-med.ac.jp
Abstract
BACKGROUND: For human ICSI, sperm are normally immobilized immediately prior to injection. However, there are some situations when only sperm of questionable viability are available. There are few evaluations of fertilization or developmental problems in human or animal models using sperm having known intervals between immobilization and injection. METHODS: Immobilized human sperm were maintained for 1-24 h in 10% polyvinylpyrrolidone (PVP) before injection into mouse oocytes. Mouse sperm heads were similarly maintained in either PVP or a high potassium-containing 'nucleus isolation medium' (NIM) before ICSI and embryo development to the blastocyst stage. RESULTS: Immobilized human sperm activated mouse oocytes comparably to controls even 24 h after immobilization. However, mouse sperm heads showed a decrease in activating ability 6 h after isolation, either in PVP or NIM. A significant reduction in blastocyst development occurred if mouse sperm heads were maintained for even 1 h in PVP. After 6 h, no blastocysts formed, with arrest occurring at the morula stage. NIM provided partial protection for up to 3 h. CONCLUSIONS: Immobilized human sperm maintained oocyte activating activity for 24 h. However, mouse sperm are susceptible to alterations that affect both fertilization and development.
BACKGROUND: For human ICSI, sperm are normally immobilized immediately prior to injection. However, there are some situations when only sperm of questionable viability are available. There are few evaluations of fertilization or developmental problems in human or animal models using sperm having known intervals between immobilization and injection. METHODS: Immobilized human sperm were maintained for 1-24 h in 10% polyvinylpyrrolidone (PVP) before injection into mouse oocytes. Mouse sperm heads were similarly maintained in either PVP or a high potassium-containing 'nucleus isolation medium' (NIM) before ICSI and embryo development to the blastocyst stage. RESULTS: Immobilized human sperm activated mouse oocytes comparably to controls even 24 h after immobilization. However, mouse sperm heads showed a decrease in activating ability 6 h after isolation, either in PVP or NIM. A significant reduction in blastocyst development occurred if mouse sperm heads were maintained for even 1 h in PVP. After 6 h, no blastocysts formed, with arrest occurring at the morula stage. NIM provided partial protection for up to 3 h. CONCLUSIONS: Immobilized human sperm maintained oocyte activating activity for 24 h. However, mouse sperm are susceptible to alterations that affect both fertilization and development.
Authors: A De Vos; M Abraham; N Franceus; P Haentjens; H Tournaye; G Verheyen; H Van de Velde Journal: J Assist Reprod Genet Date: 2015-05-01 Impact factor: 3.412
Authors: Luis Águila; Ricardo Felmer; María Elena Arias; Felipe Navarrete; David Martin-Hidalgo; Hoi Chang Lee; Pablo Visconti; Rafael Fissore Journal: Reproduction Date: 2017-09 Impact factor: 3.906