title: Analysis of global gene expression following mouse blastocyst cryopreservation.
abstract: BACKGROUND
  The aim of this study was to examine the effect of the cryopreservation procedure (slow freezing or vitrification) and cryoprotectants (1,2-propanediol or dimethylsulphoxide) on mouse blastocyst gene expression.
  
  
  METHODS
  Cultured mouse blastocysts were cryopreserved with different protocols. Following thawing/warming, total RNA from re-expanded blastocysts was isolated, amplified and then analyzed using mouse whole-genome microarrays.
  
  
  RESULTS
  Compared with non-cryopresevered control blastocysts, gene expression was only significantly altered by slow freezing. Slow freezing affected the expression of 115 genes (P < 0.05). Of these, 100 genes exhibited down-regulation and 15 genes were up-regulated. Gene ontology revealed that the majority of these genes are involved in protein metabolism, transcription, cell organization, signal transduction, intracellular transport, macromolecule biosynthesis and development. Neither of the vitrification treatment groups showed statistically different gene expression from the non-cryopreserved control embryos. Hierarchical cluster analysis, did however, reveal that vitrification using 1,2-propanediol could result in a gene expression profile closest to that of non-cryopreserved blastocysts.
  
  
  CONCLUSIONS
  Investigating the effects of cryopreservation on cellular biology, such as gene expression, is fundamental to improving techniques and protocols. This study demonstrates that of the cryopreservation regimens employed, slow freezing induced the most changes in gene expression compared with controls.
authors.affiliation: Department of Zoology, The University of Melbourne, Parkville, Victoria 3010, Australia. mlarman@unimelb.edu.au
authors.forename: M G
authors.initials: MG
authors.lastname: Larman
authors.forename: M G
authors.initials: MG
authors.lastname: Katz-Jaffe
authors.forename: B
authors.initials: B
authors.lastname: McCallie
authors.forename: J A
authors.initials: JA
authors.lastname: Filipovits
authors.forename: D K
authors.initials: DK
authors.lastname: Gardner
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000166:cytology*; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D005260:Female; D005615:Freezing; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D020411:Oligonucleotide Array Sequence Analysis; D019946:Propylene Glycol / Q000494:pharmacology; D060888:Real-Time Polymerase Chain Reaction; D058989:Vitrification
chemical_list: D003451:Cryoprotective Agents; D019946:Propylene Glycol; D004121:Dimethyl Sulfoxide