Figure 2. Effect of different embryo culture conditions and types of fertilization on blastocyst gene expression.

Microarrays were performed on blastocysts either generated naturally and cultured in WM or KAA with 5% or 20% oxygen (Effect-of-Culture experiments, A-D), or produced by IVF, ICSI or naturally and cultured in WM and 20% oxygen (Effect-of-Fertilization experiments, E-H), with naturally-derived blastocysts as controls. A) Number of transcripts altered after each culture condition shows a strong impact of suboptimal WM and high oxygen on transcription. B) Principal Component Analysis (PCA) indicates that oxygen concentration has a more robust effect on gene expression than culture medium composition. C) Venn diagram of concordant gene misexpression across the 4 culture conditions. D) Ingenuity Pathway Analysis (IPA) highlighting the predominant networks (network score ≥30) associated with the gene expression changes. E-H) Same as A-D for the Effect-of-Fertilization experiments. E) There was a severe effect of fertilization by ICSI on blastocyst gene expression, which F) contributed significantly to PCA clustering. G) Venn diagram comparing the concordance of gene misexpression after each fertilization type, with H) top IPA networks associated with the gene lists. WM Whitten's medium; KAA potassium simplex optimization medium with amino acids; IVC in vitro culture, IVF in vitro fertilization, ICSI intracytoplasmic sperm injection.