A long non-coding RNA-messenger RNA regulatory network associated with residual feed intake in the olfactory tissue...

Residual feed intake (RFI) is a key indicator for assessing feed efficiency in animals. Although olfactory cues are known to influence feeding behavior, their underlying molecular mechanisms in RFI regulation remain unclear. This study characterized the expression profiles of long non-coding RNAs (lncRNAs) and mRNAs in the olfactory tissue of Tianfu Nonghua ducks with divergent RFI phenotypes. RNA sequencing was conducted on olfactory tissue samples from low-RFI (n = 6) and high-RFI (n = 6) individuals. A total of 40 differentially expressed lncRNAs and 157 differentially expressed mRNAs were identified. Target gene prediction revealed 88 putative lncRNA target genes, primarily regulated through trans-acting mechanisms. Functional enrichment analysis highlighted significant involvement in neuroactive ligand-receptor interactions, neurotransmitter transport, and metabolic pathways. Notably, differentially expressed G protein-coupled receptors (GPCRs) were enriched in neuroactive ligand-receptor interaction pathways, suggesting their potential role in modulating olfactory signal transduction. Co-expression network analysis identified 155 lncRNA-mRNA regulatory pairs, with key interactions involving lncRNAs ENSAPLG00000024078.1 and ENSAPLG00000030384.1 and their associated target mRNAs: IQCM, LAG3, GBX2, SLC6A6, and RP1L1. These findings provide novel insights into lncRNA-mRNA regulatory networks within duck olfactory tissue and suggest a potential mechanism by which olfactory signaling may influence feed efficiency.