Differential expressions between embryonic stages. Venn diagrams on gene expression differences identified between embryonic stages with PCR and IVT amplified samples (A). The distribution of the EST positions within the referenced transcripts from the Unigene Bos taurus index (or Bt.) and the distribution of the EST size were represented by box plots (B, C). Positions within the Bt. were expressed as % of the whole Bt. size, starting from the 5' end which is defined here as 0 (B). Sizes were expressed in base pairs (C). Boxes from the box-plots extended from the 25th percentile to the 75th percentile with a horizontal bar representing the median. Statistical significance between median EST size or EST positions has not been evaluated.