Expression of OPA1 and Mic60 genes and their association with mitochondrial cristae morphology in Tibetan sheep

In order to investigate the relationship between the expression of OPA1 and Mic60 genes and the shape of mitochondrial cristae and to explore the mechanism of Tibetan sheep adapting to a high altitude hypoxia environment, we investigate respiratory rate, mitochondrial cristae and the expression of OPA1 and Mic60 in four different tissues (myocardial, skeletal muscle, spleen and kidney) in Tibetan sheep and Small Tail Han sheep. Tibetan sheep had a higher respiratory rate than Small Tail Han sheep (p < 0.01). In the same tissue, the expression of OPA1 and Mic60 was higher (p < 0.05) in Tibetan sheep than Small Tail Han sheep. Between tissues, the expression of OPA1 and Mic60 was found to be lower (p < 0.05) in spleen than the other three tissues in both breeds. Mitochondrial cristae was dense and clear in myocardial and skeletal muscle but was relatively sparse and slightly swollen in kidney. In spleen, cristae was least and swollen and the gap between the cristae was large. The width of the mitochondrial cristae in the spleen was significantly larger than the width between the inner and outer membranes; however, it had little difference in the other three tissues. The width of mitochondrial cristae was significantly larger in the spleen than that in other tissues (p < 0.05). The numbers of mitochondrial cristae in the four tissues of Tibetan sheep were larger than those in Small Tail Han sheep (p < 0.05). The unique characters of the mitochondrial cristae in Tibetan sheep may be related to its adaption to a high altitude hypoxia environment.