Correlation between BPI gene upstream CpG island methylation and mRNA expression in piglets

Area of Science:

• Animal Science
• Molecular Biology
• Epigenetics

Background:

• Postweaning diarrhea and edematous disease in piglets cause significant economic losses.
• Escherichia coli F18 is the primary pathogen responsible for these conditions.
• Bactericidal/permeability-increasing protein (BPI) is vital for host innate immunity.

Purpose of the Study:

• To investigate the relationship between CpG island methylation in the BPI gene and its mRNA expression.
• To identify potential regulatory roles of CpG methylation in BPI gene expression during piglet development.

Main Methods:

• Bisulfite sequencing PCR (BSP) to analyze BPI gene upstream CpG island methylation status.
• Fluorescence quantitative PCR to measure BPI mRNA expression in piglet duodenal tissues.
• Pearson's correlation analysis to assess the association between methylation and expression levels.

Main Results:

• The BPI gene upstream CpG island contains 10 CpG sites, all found to be methylated.
• CpG island methylation levels were lowest in 30-day-old piglets and significantly lower than in 8-day-old piglets.
• BPI mRNA expression was highest in 30-day-old piglets and showed a significant negative correlation with CpG island methylation.

Conclusions:

• Demethylation of the BPI gene upstream CpG island is associated with improved BPI mRNA expression.
• Specific CpG sites (CpG_1, CpG_3, CpG_4, CpG_7, and CpG_10) may play critical roles in regulating BPI gene expression.
• Epigenetic regulation via DNA methylation is a key mechanism influencing BPI's role in piglet defense against enteric diseases.