This study aimed to investigate the carnosine content and ATP-grasp domain-containing protein 1 (CARNS1) gene expression and their relationship with breast meat of Black Chinese (BC), KU-Phuparn (KP), Pradu Hang Dam (PD), and Black Chinese × Pradu Hang Dam (Sri Mok: SM) to aid in the selection and mating programs for developing functional meat in Thai chicken populations. The results show that the carnosine content in each breed and breed group varied from 428.08 to 553.93 mg/100 g, whereas the relative expression of CARNS1 ranged from 0.84 to 1.56. The BC and KP chicken breeds had a higher carnosine content (p < 0.01) and higher CARNS1 expression level (p < 0.05) than the SM and PD chicken breeds. The carnosine content and relative gene expression for each age ranged from 423.02 to 577.83 mg/100 g and 0.68 to 1.83, respectively. At 4 weeks of age, the carnosine content (p < 0.01) and gene expression (p < 0.05) were the highest. However, they decreased as chicken age increased further. The carnosine content and gene expression linearly decreased as chicken age increased (p < 0.01). The correlation coefficient between the level of gene expression and carnosine content was moderately positive. The results from this study showed that different breeds and ages of chickens have different amounts of carnosine, and CARNS1 could act as a biomarker to study marker-assisted selection to improve functional meat in the chicken population in Thailand.
Keywords: CARNS1; Thai native chicken; black-bone chicken; carnosine; gene expression.