title: Building a better mouse embryo assay: effects of mouse strain and in vitro maturation on sensitivity to contaminants of the culture environment.
abstract: OBJECTIVE
  The aim of this study is to compare the sensitivity of the standard one-cell mouse embryo assay (MEA) to that using in vitro-matured oocytes from hybrid and outbred mice.
  
  
  METHODS
  The study was done by culturing embryos in the presence or absence of two concentrations (0.0005 or 0.001 % v/v) of Triton X-100 (TX100). Embryonic development, blastocyst cell numbers (total and allocation to the trophectoderm [TE] and inner cell mass [ICM]), and blastocyst gene expression were evaluated.
  
  
  RESULTS
  Neither concentration of TX100 affected (P > 0.05) cleavage, blastocyst development, or hatching in one-cell embryos from BDF1 mice. However, all cell number endpoints were reduced (P < 0.05) by the high concentration of TX100 and the number of ICM cells was reduced (P < 0.05) by the low concentration of TX100. Inhibitory (P < 0.05) effects of the high concentration of TX100 were observed in in vitro maturation (IVM) embryos from BDF1, CF1, and SW, but not ICR, mice. Cell number and allocation were negatively affected by the high concentration of TX100 in CF1 and SW embryos, but not in BDF1 or ICR embryos. The only developmental endpoints affected by the low concentration of TX100 were cleavage of BDF1 oocytes, blastocyst development of SW embryos, and cell numbers (total and inner cell mass (ICM)) of SW blastocysts.
  
  
  CONCLUSIONS
  The sensitivity of the MEA to TX100 is improved by using embryos from in vitro-matured oocytes, using oocytes from some outbred (SW or CF1, not ICR) strains of mice, and evaluating blastocyst cell number and allocation.
authors.affiliation: National Foundation for Fertility Research, Lone Tree, CO, 80124, USA. jherrick@fertilityresearch.org.
authors.forename: Jason R
authors.identifier: http://orcid.org/0000-0002-1123-0958
authors.initials: JR
authors.lastname: Herrick
authors.affiliation: National Foundation for Fertility Research, Lone Tree, CO, 80124, USA.
authors.forename: Trevor
authors.initials: T
authors.lastname: Paik
authors.affiliation: National Foundation for Fertility Research, Lone Tree, CO, 80124, USA.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Strauss
authors.affiliation: Colorado Center for Reproductive Medicine, Lone Tree, CO, 80124, USA.
authors.forename: William B
authors.initials: WB
authors.lastname: Schoolcraft
authors.affiliation: National Foundation for Fertility Research, Lone Tree, CO, 80124, USA.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Krisher
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000187:drug effects; D046149:Embryo Culture Techniques / Q000379:methods; D004622:Embryo, Mammalian / Q000187:drug effects; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D059471:In Vitro Oocyte Maturation Techniques / Q000379:methods*; D051379:Mice; D017830:Octoxynol / Q000008:administration & dosage*; D009865:Oocytes / Q000187:drug effects / Q000254:growth & development*; D011247:Pregnancy
chemical_list: D017830:Octoxynol
keywords: In vitro maturation (IVM); Mouse embryo assay (MEA); Quality control