Myogenin is a gene belonging to the MyoD family, which codes for the bHLH transcription factor playing a key role in myogenesis. It affects the processes of differentiation and maturation of myotubes during embryogenesis. Fragments of the porcine myogenin coding sequence and promoter region were amplified and subjected to MSSCP analysis. TC transition recognised by the MaeIII restriction enzyme in exon 1 was revealed, which appeared to be a silent mutation in the region of the transactivation domain. No other polymorphism was found either in the remaining coding sequence or the promoter region.