(a) Prediction of the distribution of binding sites for an intestine-specific transcription factor. The binding sites of intestine-specific transcription factors (e.g., CDX2 (red), GATA4 (blue), HNF4A (green), and TCF4 (yellow)) are highlighted on the promoter region of the MUC2 gene from chicken, turkey and quail. Highly conserved DNA sequences between avian species are marked with a black box; (b) Viral vector construct. Construct contains 2.9 kb chicken MUC2 promoter. Located downstream of the promoter is eGFP; (c) Confirmation of two primer sets. Two primer sets were utilized to confirm the presence of the transgene in animals. L (DNA ladder), Wt (wild-type), Tg (transgenic quail), + (positive control), − (negative control).