Molecular analysis of six skeletal muscles of the African cheetah, a case study

Abstract

The African cheetah (Acinonyx jubatus) is one of the fastest animals on earth, reaching running speeds of greater than 110 km/h and accelerating to 110 km/h in 3s. Despite these exceptional speeds, little analysis has been done on their skeletal muscles. The aim of the current study was to investigate molecular aspects of skeletal muscle from the Acinonyx jubatus. Samples were collected from six muscles of the cheetah: longissimus dorsi (LD), supraspinatus (SS), infraspinatus (IS), semimembranosus (SM), semitendinosus (ST), biceps femoris (BF). Samples were compared to slow twitch (soleus) and fast twitch (plantaris) muscle of rat and human vastus lateralis muscle. MCT1, MCT4, myostatin and GLUT4 protein levels were measured by western blot. Cheetah muscles contained lower levels of MCT1 than rat soleus. MCT1 levels were high in soleus muscle, indicative of its integral role in transporting lactate into slow twitch muscle. Levels of GLUT4 were higher in the cheetah SS, IS, ST, BF than in LD, SM, and both rat muscles which may be reflective of the different glucose uptake and exercise capacity. Lower levels of myostatin were noted in cheetah compared to rat muscle and this may contribute to the lean and highly muscular physique of the cheetah and also aid strength for elite sprinting speed. Analysis of cheetah muscle characteristics provides insight into the molecular basis of their extreme sprinting ability.