Based on the sequencing results and the published chicken PAX7 gene sequence in Genbank (Accession No.: NC_006108), pairs of PCR primers were designed to amplify the fragment (588 bp) of the chicken PAX7 gene containing the 31- bp indel. The primer sequences were 5' CTT TTT CTC TCT CCC CTT CC 3' (forward) and 5' CAG ACC CTC AGC ACA ACT CA 3' (reverse).