Identification of a chicken (Gallus gallus) endogenous reference gene (Actb) and its application in meat adulteration

- A chromosomal gene Actb is selected as an endogenous reference gene for chicken.
- The Actb gene exists in a single copy in the chicken genome.
- The quantitative detection limit is 10 pg of DNA, which equals to 8 copies.

The genes commonly used to determine meat species are mainly mitochondrial, but the copy numbers of such genes are high, meaning they cannot be accurately quantified. In this paper, for the first time, the chromosomal gene Actb was selected as an endogenous reference gene for chicken species. It was assayed in four different chicken varieties and 16 other species using both qualitative and quantitative PCR. No amplification of the Actb gene was found in species other than chicken and no allelic variations were detected in chicken. Southern blot and digital-PCR confirmed the Actb gene was present as a single copy in the chicken genome. The quantitative detection limit was 10 pg of DNA, which is equivalent to eight copies. All experiments indicated that the Actb gene is a useful endogenous reference gene for chicken, and provides a convenient and accurate approach for detection of chicken in feed and food.