To explore the expression profile of the CaNAα gene in phenotypically distinct muscles during early growth development,quantitative real-time PCR was applied to detect the CaNAα mRNA in the lateral gastrocnemius,soleus and extensor digitorum longus muscles at different weeks of ages (0,1,3,5,7,9 w) in Recessive White chicken (fast-growing chicken breed) and Qingyuan partridge chicken (slow-growing chicken breed).The results showed that except for the soleus muscle in Qingyuan partridge chicken,the CaNAα mRNA of other muscles in the two chicken breeds was firstly increased,then decreased and finally increased again.The highest CaNAα mRNA level in the entensor digitorum longus in both chicken breeds peaked at 1 w,and the lowest level appeared at 7 w in Qingyuan partridge chicken while at 5 w in Recessive White chicken.The CaNAα mRNA in the lateral gastrocnemius and soleus muscles in Qingyuan partridge chicken peaked at 3 w,while at 9 w in Recessive White chicken.Overall,the CaNAα expression in the soleus was lower than that in the extensor digitorum longus and lateral gastrocnemius muscles.The CaNAα mRNA of the three phenotypically distinct muscles in Qingyuan partridge chicken was higher at 0 and 3 w,but lower at 9 w than that of Recessive White chicken,with extremely significantly difference appeared at 3 w (P＜0.01).Overall,the CaNAα gene in the chicken muscle showed specific developmental patterns,which may be related to the breed,age,phenotype,and the chicken meat quality as well.