Abstract: In order to elucidate the muscle contraction mechanism and related gene expression pattern of Monochamus alternatus,the myosin light chain 2 gene from Monochamus alternatus,called MaMLC-2 (GenBank:KM371003) was cloned by using cDNA library construction.The cloned cDNA of MaMLC-2 was 882 bp in length,which contains a 618 bp open reading frame (ORF) encoding 205 amino acids with a calculated molecular mass of 22.26 kDa and an isoelectric point of 4.66.MaMLC-2 showed the highest homology with Tribolium castaneum (96%),and has amino acid sequence homology with the myosin light chain 2 from 8 species of insects such as Gryllotalpa orientalis (85% -88%). M.alternatus and T.castaneum on the same branch in the phylogenetic tree based on insect myosin light chain 2 amino acids.MaMLC-2 was hydrophilic,which contains 2 EF-hand functional domains,and both of the domains are comprised of 29 amino acids.The first EF-hand functional domain can bind Ca²⁺.There was a Ca²⁺ binding site in the first EF-hand domain.SWISS-MODEL prediction results showed that MaMLC-2 has 2 helix-loop-helix structures.The relative expression levels of MaMLC-2 detected by RT-qPCR indicated that the expression levels of MaMLC-2 in pupae and larvae were higher than that in adults,and the expression level in head of adults was the highest,nevertheless,the expression level in abdomen of adults was the lowest.The MaMLC-2 were prominently and differently expressed in all of the adult parts(P<0.05).

Key words: Monochamus alternatus, Myosin light chain 2, Gene expression pattern, RT-qPCR

CLC Number: 

• Q966