# Transcriptome Dynamics and Regulatory Networks of Postnatal Muscle Development in Leizhou Black Goats

## TL;DR

This study explores how muscle develops in Leizhou Black goats by analyzing gene activity at different ages, revealing key genes and networks involved in muscle maturation.

## Contribution

The study identifies novel transcripts and regulatory networks specific to postnatal muscle development in goats, offering new genetic resources for breeding.

## Key findings

- Dynamic gene expression and alternative splicing events were observed during muscle development in Leizhou Black goats.
- A significant transcriptional shift occurred between six months and two years, involving genes related to muscle contraction and metabolism.
- Novel transcripts enriched in mitochondrial functions were discovered, indicating gaps in the current goat genome annotation.

## Abstract

Postnatal muscle development involves complex transcriptional regulation that remains poorly characterized in goats. This study employed RNA-Seq to profile the Longissimus dorsitranscriptome of Leizhou Black goats across three developmental stages: birth, six months, and two years. We identified dynamic gene expression patterns, widespread alternative splicing events, and stage-specific co-expression networks that collectively orchestrate muscle maturation. A significant transcriptional shift occurred between six months and two years, marked by the downregulation of proliferation-related genes (e.g., RRM2, TOP2A) and the activation of pathways governing muscle contraction and energy metabolism. Functional enrichment analyses highlighted the importance of PI3K-Akt, PPAR, and calcium signaling pathways throughout development. Additionally, 905 novel transcripts were discovered, many enriched in mitochondrial functions, indicating incompleteness in the current goat genome annotation. Weighted gene co-expression network analysis revealed modules correlated with developmental stages, and protein–protein interaction analysis identified hub genes regulating cell cycle progression and muscle function. Key results were validated via qRT-PCR, confirming the temporal expression patterns of genes such as CYP4B1, HACD1, and ACTC1. These findings provide mechanistic insights into the transcriptional reprogramming driving postnatal muscle development and offer valuable genetic resources for improving meat production in goats through molecular breeding.