Abstract

Heat shock protein 47 (Hsp47) is a collagen-specific molecular chaperone that is indispensable for molecular maturation of collagen. In this study,hsp47andhsp47-likecDNAs were cloned and characterized in grass carp (Ctenopharyngodon idella). The cDNAs were 1212 and 1218 base pairs long, respectively, and included an open reading frame encoding 403 and 405 amino acids. The molecular phylogeny based on the deduced amino acid sequences indicated that the correct sequences of thehsp47andhsp47-likecDNA were obtained and the deduced proteins clustered distinctly into teleost clades. Primary structure analysis and characterization of Hsp47 and Hsp47-like shared the basic structure and biofunctions of Hsp47 in vertebrates. The spatial pattern of gene expression revealed thathsp47andhsp47-likewere relatively ubiquitous in different tissues and highly expressed in heart and skin. The expression levels ofhsp47andhsp47-likeand type I collagen mRNAs varied similarly in different tissues. Type I collagen content increased significantly with the increase of water velocity in the muscle of grass carp in response to aerobic exercise. Among the gene expression changes ofhsp47,hsp47-like,col1a1andcol1a2in muscle that occurred in response to aerobic exercise, the change of type I collagen was most strongly correlated withhsp47expression. Additionally, col1a1 showed the highest correlation withhsp47-likeandcol1a2showed the highest correlation withhsp47. These findings suggest that grass carp Hsp47 and Hsp47-like are closely related to type I collagen synthesis. This study firstly suggests fish aerobic exercise can improve type I collagen content and Hsp47 gene expression in muscle of grass carp.Keywords:grass carp;hsp47;collagen;molecular cloning;gene expression