Background: Mechanisms underlying yak adaptation to high-altitude environments have
been investigated at the levels of morphology, anatomy, physiology, genome and transcriptome, but
have not been explored at the proteome level.
Objective: The protein profiles were compared between yak and cattle to explore molecular mechanisms
underlying yak adaptation to high altitude conditions.
Methods: In the present study, an antibody microarray chip was developed, which included 6,500
mouse monoclonal antibodies. Immunoprecipitation and mass spectrometry were performed on 12
selected antibodies which showed that the chip was highly specific. Using this chip, muscle tissue proteome
was compared between yak and cattle, and 12 significantly Differentially Expressed Proteins (DEPs)
between yak and cattle were identified. Their expression levels were validated using Western blot.
Results: Compared with cattle, higher levels of Rieske Iron-Sulfur Protein (RISP), Cytochrome C oxidase
subunit 4 isoform 1, mitochondrial (COX4I1), ATP synthase F1 subunit beta (ATP5F1B), Sarcoplasmic/
Endoplasmic Reticulum Calcium ATPase1 (SERCA1) and Adenosine Monophosphate Deaminase1
(AMPD1) in yak might improve oxygen utilization and energy metabolism. Pyruvate Dehydrogenase
protein X component (PDHX) and Acetyltransferase component of pyruvate dehydrogenase
complex (DLAT) showed higher expression levels and L-lactate dehydrogenase A chain (LDHA)
showed lower expression level in yak, which might help yak reduce the accumulation of lactic acid. In
addition, higher expression levels of Filamin C (FLNC) and low levels of AHNAK and Four and a half
LIM domains 1 (FHL1) in yak might reduce the risks of pulmonary arteries vasoconstriction, remodeling
Conclusion: Overall, the present study reported the differences in protein profile between yak and cattle,
which might be helpful to further understand molecular mechanisms underlying yak adaptation to
high altitude environments.