Transcriptome analysis reveals age-specific growth characteristics in the rumen of Hanwoo (Korean native cattle) steers.

Abstract

Background: Hanwoo cattle are a Korean breed renowned for their cultural significance and high-quality beef, characterized by low cholesterol and a high unsaturated fat ratio. Their growth is divided into a growing stage focused on development and a fattening stage for marbling. Proper feed management, considering genetic and environmental factors, is vital for maximizing growth potential. The rumen plays a crucial role in digestion and gene expression regulation, with rumen fermentation being central to nutrient absorption and cattle health. In this study, we conduct a transcriptome analysis of the rumen at eight timepoints. Our goal is to identify genetic factors that influence the growth of Hanwoo steers to enhance our understanding of the rumen's functions during Hanwoo growth.

Results: In the RNA-sequencing analysis of Hanwoo steer rumen, differential gene expression was examined over eight timepoints, highlighting significant genetic changes, particularly between 12 and 26 months. The results of a weighted gene co-expression network analysis were identified and organized into three modules: turquoise, blue, and yellow. The turquoise module, linked to immune response, showed significantly down-regulation in genes at 30 months. The blue module, associated with steroid metabolism, was notably up-regulated at 26 months. The yellow module's genes showed a consistent increase in expression with growth. These modules and their functional annotations provide a deeper understanding of the biological processes during Hanwoo growth, highlighting the intricate relationship between gene expression and cattle development.

Conclusions: The growth stages of Hanwoo steers were explored in our investigation utilizing rumen transcriptome data. The rumen plays a critical role in their development, particularly during the growing and fattening stages. Proper feed management, considering the rumen's function, is essential for optimal growth. Transcriptome analysis helps identify genes associated with growth and provides insights for cattle breeding and management practices. Understanding the complex connection between gene expression and Hanwoo development is essential for maximizing productivity and health.