MicroRNA buffering and altered variance of gene expression in response to Salmonella infection

Area of Science:

• Genomics
• Molecular Biology
• Immunology

Background:

• MicroRNAs (miRNAs) are investigated for their role in regulating gene expression variation.
• Conflicting reports exist regarding the buffering capacity of miRNAs.
• Understanding miRNA function during pathogen infection is critical.

Purpose of the Study:

• To investigate the gene expression buffering role of miRNAs in pigs challenged with Salmonella.
• To analyze how miRNAs affect gene expression variance before and after infection.

Main Methods:

• Sequencing of miRNA and mRNA from pig whole blood samples.
• Analysis of inter-individual gene expression variation.
• Comparison of expression variance between miRNA targets and non-targets.
• Assessment of expression changes post-Salmonella challenge.

Main Results:

• Putative miRNA targets showed significantly lower expression variance than non-targets for moderately and lowly expressed genes.
• miRNA targets exhibited reduced expression variance after Salmonella challenge, unlike non-targets.
• RNA binding proteins (RBPs) were enriched among miRNA targets with reduced expression variance post-challenge.
• Targets of less-conserved miRNAs showed lower expression variance compared to targets of conserved miRNAs.

Conclusions:

• miRNAs play a significant buffering role in gene expression, especially for less abundant transcripts.
• The reduced expression variation of RNA binding proteins mediated by miRNAs is important in the host response to Salmonella.
• miRNA conservation influences their gene expression buffering efficiency.