Taurine was found to up-regulate the expression of the mitochondrial fusion proteins Mfn1, Mfn2, and OPA1 while down-regulating the expression of the mitochondrial fission proteins FIS1 and Drp1 in both the FLHS hens and the steatosis LO2 cells, indicating a regulatory effect of taurine on the mitochondrial dynamic balance, which is essential for the maintenance of normal mitochondrial morphology and function. Here, FIS1 is linked to steatosis.