Cloning and expression analysis of BLT1-like genes from zebrafish(Danio rerio)

In order to research the functions of BLT1 in the development and vaccination process of zebrafish,two leukotriene B₄ receptor 1-like(BLT1-like) genes, BLT1-like1 and BLT1-like2,from zebrafish were cloned,which encoded 339 and 356 amino acids,respectively.Through sequence and structure analysis,it was found that both of the two proteins belong to rhodopsin subfamily of G protein coupled receptors(GPCR),with typical features of GPCR and have a moderate identity of above 31% with human BLT1.Additionally,when fused with enhanced green fluorescent protein(EGFP) and expressed in CHO cells,a good membrane-bound property was found.And Western blotting experiment verified their specific interactions with human BLT1 polyclonal antibodies.Besides,the results of RT-qPCR showed that during the embryo development of zebrafish,the expression of BLT1-like1 was up-regulated significantly at 12 h,which was 18 times higher than that of 1 h.While the expression level of BLT1-like2 changed sharply at 24 h,which was 34 times higher than that of 1 h.In addition,both of the two genes had a relatively high expression level in the heart and liver,while with a relatively low expression level in the intestine,skin and eye.Conclusively,our study indicates that there might exist more than one BLT1 gene in zebrafish and this will be helpful to clone and characterize BLT1 genes from other fishes.