According to the authors, "RT-PCR was used to amplify cDNA fragments of ... 450 bp for ... Grg5/AES from HH stage 12 quail embryo mRNA. Primers used are the following: Grg5/AES forward 5′-GCGACAAACTAGCCAGCGAG-3′, reverse 5′-CTGATGTCTCCCCATCGTCGTC-3′. Sequences were submitted to GenBank with the following accession number: AY834285. Sequence shown is quail. Link is the best fit chicken gene.