Figure 4: The abundance of Oct4 (a) and Cdx2 (b) transcripts in in vitro culture of the mouse blastocyst. mRNA from embryos was reverse-transcribed and subjected to real-time quantitative PCR. All levels were normalized to GAPDH mRNA expression. Values with superscripts “*” refer to significant (P < 0.05) differences in relative transcript abundance between groups. Oct4: Octamer-binding transcription factor 4; Cdx2: Caudal type homeobox 2; PCR: Polymerase chain reaction.