title: Microfilament disruption is required for enucleation and nuclear transfer in germinal vesicle but not metaphase II human oocytes.
abstract: OBJECTIVE
  To evaluate the usefulness of microfilament disruption before enucleation and nuclear transfer in human oocytes at different stages of maturation.
  
  
  METHODS
  Prospective experimental study.
  
  
  METHODS
  Private clinics.
  
  
  METHODS
  Infertile couples undergoing assisted reproduction attempts.
  
  
  METHODS
  Oocyte enucleation and nuclear transfer, activation of reconstructed oocytes.
  
  
  METHODS
  Oocyte survival, nuclear transfer efficacy, activation outcomes.
  
  
  RESULTS
  Survival rate and nuclear transfer efficacy of germinal vesicle oocytes exposed to the microfilament disrupting agent cytochalasin B before enucleation were 88% and 80%, respectively. These figures dropped, respectively, to 8% and 2% when cytochalasin treatment was omitted. By contrast, cytochalasin-treated and -untreated metaphase II oocytes showed similar survival rate (87% vs. 90%) and nuclear transfer efficacy (78% vs. 87%). This also applied to metaphase II oocytes matured in vitro from the germinal vesicle stage. Cytochalasin treatment did not affect activation rate of reconstructed oocytes, but it increased the occurrence of oocytes with multiple female pronuclei.
  
  
  CONCLUSIONS
  Microfilament disruption before enucleation is required for germinal vesicle oocytes but not for metaphase II oocytes.
authors.affiliation: MAR&Gen, Molecular Assisted Reproduction and Genetics, Granada, Spain. cmendoza@ugr.es
authors.forename: Jan
authors.initials: J
authors.lastname: Tesarik
authors.forename: Francisco
authors.initials: F
authors.lastname: Martinez
authors.forename: Laura
authors.initials: L
authors.lastname: Rienzi
authors.forename: Filippo
authors.initials: F
authors.lastname: Ubaldi
authors.forename: Marcello
authors.initials: M
authors.lastname: Iacobelli
authors.forename: Carmen
authors.initials: C
authors.lastname: Mendoza
authors.forename: Ermanno
authors.initials: E
authors.lastname: Greco
mesh_terms: D008841:Actin Cytoskeleton / Q000502:physiology*; D000001:Calcimycin / Q000494:pharmacology; D002467:Cell Nucleus / Q000502:physiology; D003571:Cytochalasin B / Q000494:pharmacology; D005260:Female; D006801:Humans; D007476:Ionophores / Q000494:pharmacology; D008297:Male; D008677:Metaphase / Q000502:physiology; D008846:Micromanipulation / Q000379:methods*; D053652:Nuclear Transfer Techniques; D009865:Oocytes / Q000502:physiology*; D011446:Prospective Studies
chemical_list: D007476:Ionophores; D000001:Calcimycin; D003571:Cytochalasin B