IGFBP2 gene cloning, tissue expression and bioinformatics analysis of Xiangsu hybrid pig

【Objective】In order to explore the expression difference of insulin-like growth factor binding protein 2gene(IGFBP2) in different tissues of Xiangsu hybrid pigs at different growth stages, and to provide basic data for further analysis of the molecular mechanism of IGFBP2 gene on growth and development of Xiangsu hybrid pigs. 【Method】The coding region(CDS) sequence of IGFBP2 gene of Xiangsu hybrid pig was amplified by PCR. The CDS sequence of IGFBP2 gene was analyzed by online software and the phylogenetic tree was constructed by using cloned CDS. Real-time fluorescence quantitative PCR was used to detect the expression of IGFBP2 gene in various tissues of Xiangsu hybrid pigs at different stages. 【Result】The total length of the CDS of porcine IGFBP2 gene was 951 bp, encoding 316 amino acid residues. The secondary and tertiary structures of the protein was mainly random coil, and it was a hydrophilic stable protein, and the amino acid sequence of IGFBP2 protein was mainly glycine(13.0%) and leucine(12.3%). Homology analysis showed that IGFBP2 gene of Xiangsu hybrid pig was closely related to boar, cow, sheep and goat. The results of realtime fluorescence quantitative PCR showed that the relative expression of IGFBP2 gene in the heart of 3 days of age, 6 months of age and 12 months of age was extremely significantly different by comparing and analyzing the expression levels of different tissues at different stages(P<0.01,the same below). The relative expression level was higher at 3 days of age. The relative expression level in liver at 12 months of age was significantly higher than that at 3 days of age and 6 months of age(P<0.05,the same below), but there was no significant difference between 3 days of age and 6 months of age(P>0.05,the same below). The relative expression level in spleen at 3 days of age was extremely significantly higher than that at 6 and 12 months, and the relative expression level at 12 months of age was significantly higher than that at 6 months of age. The expression of 3 days of age was extremely significantly higher than 6 months of age and 12 months of age, but there was no significant difference between 6 months of age and 12 months of age. There were significant differences in the relative expression levels of kidney at 3 days, 6 months and 12 months of age. The relative expression level of IGFBP2 gene in longissimus dorsi at 6 months and 12 months of age was significantly different, and the relative expression level of IGFBP2 gene in longissimus dorsi at 3 age stages was lower. 【Conclusion】IGFBP2 gene is differentially expressed in various tissues of Xiangsu hybrid pigs at different growth stages, and is highly specifically expressed in tissues related to triglyceride and fatty acid synthesis metabolism(liver), which may indicate that IGFBP2 gene plays an important role in the regulation of fat synthesis, metabolism and deposition.