Correlation between the methylation of the FUT1 promoter region and FUT1 expression in the duodenum of piglets from newborn to weaning.

Alpha-(1,2)-fucosyltransferase (FUT1) gene has some influence on economically important traits and disease resistance. DNA methylation plays an important role in human diseases but is relatively poorly studied in pigs by regulating the mRNA expression of genes. The aim of this study was to analyze the influence of promoter methylation on the expression of FUT1 gene. We used bisulfite sequencing PCR (BSP) and qPCR to analyze the methylation of the FUT1 5'-flanking region and FUT1 mRNA expression in the duodenum of Sutai piglets from newborn to weaning. FUT1 contains three CpG islands upstream of the start codon, of which two are located in the putative promoter region containing multiple promoter elements and transcription factor binding sites, such as CpG islands, a CAAT box, SP1, and EARLY-SEQ 1. The CpG island between nucleotides -1762 and -580 had a low degree of methylation, and its methylation level was significantly lower in 35-day-old piglets than 8- and 18-day-old piglets (P < 0.05). FUT1 mRNA expression was significantly higher in 35-day-old piglets than 8- and 18-day-old piglets (P < 0.05). Pearson's correlation analysis showed that the methylation of the CpG island between nucleotides -1762 and -580 of FUT1 was significantly, negatively correlated with FUT1 mRNA expression (P < 0.05). These results demonstrate that differential methylation of CpG islands negatively regulates the expression of FUT1 in the porcine duodenum, suggesting a probable influence on the resistance of piglets to infection with ETEC F18.

New insights into the codon usage patterns of the bactericidal/permeability-increasing (BPI) gene across nine species.

Bactericidal/permeability-increasing (BPI) protein is a member of a new generation of proteins known as super-antibiotics that are implicated as endotoxin neutralising agents. Non-uniform usage of synonymous codons for a specific amino acid during translation of a protein is known as codon usage bias (CUB). Analysis of CUB and compositional dynamics of coding sequences could contribute to a better understanding of the molecular mechanism and the evolution of a particular gene. In this study, we performed CUB analysis of the complete coding sequences of the BPI gene from nine different species. The codon usage patterns of BPI across different species were found to be influenced by GC bias, particularly GC3s, with a moderate bias in the codon usage of BPI. We found significant similarities in the codon usage patterns in BPI gene among closely related species, such as Sus_scrofa and Bos_taurus. Moreover, we observed evolutionary conservation of the most over-represented codon CUG for the amino acid leucine in the BPI gene across all species. In conclusion, our analysis provides a novel insight into the codon usage patterns of BPI. This information facilitates an improved understanding of the structural, functional and evolutionary significance of BPI gene among species, and provides a theoretical reference for developing antiseptic drug proteins with high efficiency across species.

Proteomic Analysis of Duodenal Tissue from Escherichia coli F18-Resistant and -Susceptible Weaned Piglets.

Diarrhea and edema disease in weaned piglets due to infection by Escherichia coli F18 is a leading cause of economic loss in the pig industry. Resistance to E. coli F18 depends on expression of receptors on intestinal epithelial cells, and individual immunity. This study was conducted in Sutai pig E. coli F18-resistant and -susceptible full sib-pair individuals, identified on the basis of resource populations and verification of adhesion assays. The molecular mechanism underlying E. coli F18 resistance was investigated through analysis of the expression of E. coli F18 receptor associated and innate immunity proteins, using proteomics and bioinformatics techniques. Two-dimensional electrophoresis analysis revealed a total of 20 differentially expressed proteins in E. coli F18-resistant and -susceptible groups (10 upregulated and 10 downregulated). A total of 16 differentially expressed proteins were identified by MALDI TOF/TOF mass spectral analysis. According to gene ontology and pathway analysis, differentially expressed proteins were mainly involved in cell adhesion, immune response and other biologically relevant functions. Network analysis of interactions between differentially expressed proteins indicated a likelihood of their involvement in E. coli F18 infection. The expression levels of several important proteins including actin beta (ACTB), vinculin (VCL), heat stress proteins (HSPs) and transferrin (TF) in E. coli F18-resistant and -susceptible individuals were verified by Western blotting, supporting the identification of ACTB, VCL, HSPs and TF as promising candidate proteins for association with E. coli F18 susceptibility.