Transcription factors Nanog , Oct-4 and Sox-2 present in porcine tissue. Gene specific primers for Nanog (N), Oct-4 (O) and Sox-2 (S) amplified single bands of 438, 335 and 443 bp, respectively, in day 14–15 postestrus embryonic discs (A). Bands of expected sizes were also amplified in PUC cells (B) as well as in porcine fibroblasts (C). Reactions omitting the RT step produced no bands (-RT). As a loading positive control, β-actin primers (β) were included in most reactions.