Study On Sequence Variation And Tissues Expression Diversity Of Two Isoforms Of VLDLR In Goose

The very low-density lipoprotein receptor (VLDLR) is a member of LDLR family, the main function is participating in triglyceride metabolism by bounding with the triacylglycerol-rich lipoprotein. In this study, with the experiment objects of Landes goose and Tianfu meat goose, A series of bioinformatics analyses were performed to analysis and predict the sequence characteristic, the structure and function of goose VLDLR two isoforms. The expression characteristic of VLDLR two isoforms in geese were investigated by RT-PCR method. The influence of force-feeding on the expression of VLDLR gene in geese and its possible mechanism were analyzed. The results were as following:1. The goose VLDLR gene had two isoforms. TypeⅠVLDLR had a similarity of 82%, 81%, 81% and 80% at nucleic acid level, 80%, 77%, 77% and 80% at the amino acid level with rabbit, rat, mouse and human. TypeⅡVLDLR had a similarity of 90%, 82%, 81%, 81% and 80% at nucleic acid level, 92%, 70%, 70%, 80% and 79% at the amino acid level with chicken, rabbit, rat, mouse and human.2. The goose typeⅡVLDLR lacks 30 amino acid, but human, rat, mouse, rabbit, bovine lacks 28 amino acid. The absent domain of typeⅡVLDLR was O-linked sugar domain, the absent of which could affect the structure and function of VLDLR.3.There were two variation sites of amino acid between goose and chicken, six variation sites between goose and mammalian in transmembrane domain of goose VLDLR, which were the same polarity amino acid variation. In O-linked sugar domain of goose VLDLR, there were one variation sites of amino acid between goose and chicken, 9～13 variation sites of amino acid between goose and mammalian, which included serine and threonine and influenced the O- glycosylation of O-linked sugar domain.4.TypeⅠVLDLR and typeⅡVLDLR were both expressed in abdomen adipose tissue, subcutanceous adipose tissue and skeletal muscles. The expression abundance of VLDLR in skeletal muscles was higher than in adipose tissue. The expression of typeⅠVLDLR was predominant in skeletal muscles. There was no significant difference of expression abundance between typeⅠVLDLR and typeⅡVLDLR in adipose tissue.5.TypeⅠVLDLR was mainly expressed in muscles and adipose tissue where lipid metabolism was more activity. TypeⅠVLDLR bound with relative higher affinity to VLDL andβ-VLDL, and internalizes much more lipoprotein into cells than typeⅡVLDLR. It indicated that typeⅠVLDLR was correlated with the level of lipid metabolism. It was presumed that TypeⅡVLDLR played an important role in growth and development of tissues, cell differentiation.6. After overfeeding, the expression abundance of geese VLDLR isoforms could be regulated according to the change of lipid metabolism in vivo.