| In order to investigate the effects of altitude on the regulation of COX expression and the difference in expression of various organs,in this experiment,4 months old fetus of Haiyan and Zeku yaks were selected as the research objects.The expression of COX gene and protein in different tissues of yak were determined by quantitative real-time PCR and Western blotting and finally used ELISA to further determine COX content.The results indicated as follow:In the lateral comparison of 4 months old fetuses of Haiyan ahd Zeku yaks,COX1,COX2 and COX3 mRNA were the highest expression in myocardial tissues and the lowest in spleens and lungs.Longitudinal comparison of the same tissue revealed that the expression of COX3 mRNA in the livers of Haiyan yak fetuses were higher than that in the Zeku yak fetuses,but opposite in skeletal muscle tissues,and the difference was significant(P<0.05).The expression levels of COX1 and COX2 in kidney tissues of Haiyan yak fetuses were higher than those in Zeku yak fetuses,and the difference was significant(P<0.05).The COX3 protein in skeletal muscle tissues of 4 months old Zeku fetuses had higher than that of 4 months old Haiyan fetuses,and the difference was significant(P<0.05).There was no significant difference in the expression of COX1,COX2 and COX3 proteins in other tissues(P>0.05).With the incremental ascent at altitude,there was no significant difference in COX content in various tissues of yak fetuses(P>0.05),but different tissues had different COX enzyme content.The presence of COX4-2 in the brain tissues of the 4 months old yak fetuses indicated that COX4 expression was characterized by stage specificity and tissue specificity.The above results indicated that the heart had a very high energy demand in the second trimester of yak fetuses.The mitochondrial COX gene were affected by tissue and oxygen partial pressure.The COX protein expression and enzyme content of yak fetuses did not change with altitude.The mechanism by which COX function stably in long-term plateau environment and the aerobic metabolism remained relatively stable.COX regulated cellular aerobic respiration,which was essential for fetal development during pregnancy. |
