Abstract:

To elucidate the role of the MYL2 gene in muscle development and high-altitude adaptation in yak,and to explore its potential impact on meat quality and production performance,this study conducted cloning and tissue expression analysis of the MYL2 gene in Pamir yak.By cloning its coding sequence(CDS)and performing bioinformatics-based functional prediction and tissue-specific expression profiling,the functional characteristics of the MYL2 gene were further clarified.Additionally,it seeks to analyze and explore the structure and function of the MYL2 gene.Real-time quantitative PCR(RT-qPCR)technology was employed to quantify the expression levels of the MYL2 gene in various tissues of the Pamir yak,including the heart,liver,spleen,lung,kidney,pancreas,and longissimus dorsi muscle.The results indicated that the coding sequence(CDS)length of the Pamir yak MYL2 gene was 501 bp,which encoded a protein of 166 amino acids.Comparative homology analysis revealed that the MYL2 gene of Pamir yak shared the closest genetic relationship with that of the wild yak,exhibiting a similarity of 100%,while the most distant genetic relationship was observed with the chicken.The protein analysis results indicated that the molecular formula of the protein was C₈₄₂H₁₃₁₃N₂₁₉O₂₆₁S₇,with a molecular mass of 18.904 42 ku and a theoretical isoelectric point of 4.831.The instability index was measured at 28.3,suggesting that the protein was stable.Additionally,the protein contained one N-glycan modification potential site and 15 potential phosphorylation sites.Furthermore,its structure did not exhibit a transmembrane domain or signal peptide,and it was primarily localized in the cytoplasmic membrane and cell wall.The secondary structure was predominantly composed of 93 α-helices(56.02%),60 random coils(7.83%),and 13 β-sheets(36.14%).RT-qPCR results showed that MYL2 gene expression was extremely significantly higher in the heart and longissimus dorsi muscle of Pamir yak compared to other tissues,suggesting that this gene may play a key regulatory role in maintaining cardiac function and promoting skeletal muscle growth.Based on protein function prediction,MYL2 is likely involved in the development of cardiac and skeletal muscles by regulating the expression of muscle structural proteins,thereby contributing to the maintenance of locomotor capacity and thermogenic performance under cold,hypoxic plateau conditions.

Key words: Pamir yak, MYL2 gene, Gene cloning, Bioinformatics

CLC Number: 

• S823.85