title: Reversible disassembly of the actin cytoskeleton improves the survival rate and developmental competence of cryopreserved mouse oocytes.
abstract: Effective cryopreservation of oocytes is critically needed in many areas of human reproductive medicine and basic science, such as stem cell research. Currently, oocyte cryopreservation has a low success rate. The goal of this study was to understand the mechanisms associated with oocyte cryopreservation through biophysical means using a mouse model. Specifically, we experimentally investigated the biomechanical properties of the ooplasm prior and after cryopreservation as well as the consequences of reversible dismantling of the F-actin network in mouse oocytes prior to freezing. The study was complemented with the evaluation of post-thaw developmental competence of oocytes after in vitro fertilization. Our results show that the freezing-thawing process markedly alters the physiological viscoelastic properties of the actin cytoskeleton. The reversible depolymerization of the F-actin network prior to freezing preserves normal ooplasm viscoelastic properties, results in high post-thaw survival and significantly improves developmental competence. These findings provide new information on the biophysical characteristics of mammalian oocytes, identify a pathophysiological mechanism underlying cryodamage and suggest a novel cryopreservation method.
authors.affiliation: Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, United States of America.
authors.forename: Basarab G
authors.initials: BG
authors.lastname: Hosu
authors.forename: Steven F
authors.initials: SF
authors.lastname: Mullen
authors.forename: John K
authors.initials: JK
authors.lastname: Critser
authors.forename: Gabor
authors.initials: G
authors.lastname: Forgacs
mesh_terms: D000199:Actins / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D015925:Cryopreservation / Q000379:methods; D003451:Cryoprotective Agents / Q000494:pharmacology; D003599:Cytoskeleton / Q000378:metabolism*; D004548:Elasticity; D005260:Female; D005307:Fertilization in Vitro; D008280:Magnetics; D051379:Mice; D008954:Models, Biological; D008962:Models, Theoretical; D009865:Oocytes / Q000378:metabolism*; D013075:Sperm Capacitation
chemical_list: D000199:Actins; D003451:Cryoprotective Agents