Effects of mutations in porcine miRNA-215 precursor sequences on miRNA-215 regulatory function

Area of Science:

• Animal genetics and immunology
• Molecular biology and disease resistance

Background:

• MicroRNAs (miRNAs) are crucial regulators of animal growth and disease.
• Sequence variations in miRNAs can significantly alter their biological functions.
• Understanding miRNA precursor mutations is key to deciphering disease resistance mechanisms.

Purpose of the Study:

• To investigate the impact of mutations in the miRNA-215 precursor sequence on its regulatory network.
• To assess the effect of these mutations on resistance to Escherichia coli (E. coli) infection in pigs.
• To identify potential genetic markers for enhancing porcine resistance to E. coli.

Main Methods:

• Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) to detect sequence variations in pig breeds.
• Construction of wild-type (WT) and mutant miR-215 precursor expression vectors.
• Analysis of miR-215 expression, target gene (DLG5, ALCAM) expression, cytokine levels, and E. coli adhesion.

Main Results:

• A C/T mutation at position 43 in the miR-215 precursor was associated with reduced miR-215 expression.
• This C/T mutation led to increased target gene expression, elevated cytokine levels, and higher E. coli adhesion.
• An AT insertion mutation at position 6 showed no significant effects on miR-215 function or E. coli resistance.

Conclusions:

• Sequence variation in the miRNA-215 precursor can disrupt its regulatory network.
• The C/T mutation in miR-215 precursor impacts intestinal epithelial cell stability and porcine resistance to E. coli.
• Findings offer insights into miR-215 regulatory mechanisms and potential genetic markers for E. coli resistance in pigs.