# Identification of Key Candidate Genes for Muscle Growth in Liaoning Black Pigs and Duroc Pigs via Longissimus Dorsi Muscle Transcriptome Analysis

## TL;DR

This study identifies key genes involved in muscle growth by comparing the transcriptomes of two pig breeds, Liaoning Black and Duroc pigs.

## Contribution

The study provides novel insights into the molecular mechanisms of muscle growth through breed-specific transcriptomic analysis.

## Key findings

- 5051 and 9972 differentially expressed genes were identified in female and male pigs, respectively.
- Hub genes ITGB1, SRC, MYL2, PRKACA, and MAPK3 were highlighted as key regulators of muscle growth.
- qPCR validation confirmed the RNA-seq results, supporting the reliability of the findings.

## Abstract

Pig growth is an economically important trait regulated by multiple genes and signaling pathways. To explore the molecular mechanisms underlying muscle growth, RNA sequencing was conducted to compare the transcriptomic profiles of the longissimus dorsi muscle between indigenous Liaoning Black pigs (CH) and commercial Duroc pigs (HD). Muscle samples from six CH (three males and three females) and six HD (three males and three females) pigs were analyzed. Functional annotation, Gene Ontology (GO) and KEGG enrichment, and protein–protein interaction (PPI) analyses were performed. Sequencing yielded 12 high-quality datasets (Q20 > 97%, Q30 > 93%). Comparative analysis identified 5051 DEGs in females (CHF vs. HDF; 2310 upregulated and 2681 downregulated) and 9972 DEGs in males (CHM vs. HDM; 4984 upregulated and 4988 downregulated). GO terms were mainly enriched in organonitrogen compound and protein metabolic processes, while KEGG pathways were enriched in focal adhesion and insulin signaling. PPI analysis highlighted hub genes ITGB1, SRC, MYL2, PRKACA, and MAPK3. qPCR validation showed strong agreement with RNA-seq data. These findings provide valuable insights into the molecular basis of divergent muscle growth between pig breeds.