XIONG Ming-Fu, KONG Si-Yuan, ZHANG Yong-Sheng
As an important tissue of the body (accounting for approximately 40% of body weight), skeletal muscle is composed of various cell types such as muscle fibers, muscle stem cells, and endothelial cells. It participates in physiological processes including movement, energy metabolism, and internal environment homeostasis through temporal and spatial specific regulation. Its development is divided into two critical stages: embryonic and postnatal periods. Abnormal development can lead to diseases such as muscular dystrophy and directly affect the yield and quality of livestock meat. In recent years, the combination of single-cell transcriptomics (scRNA-seq) and spatial omics (single-cell spatial omics technology) has provided a high-resolution research tool for analyzing the spatiotemporal dynamic regulatory network and intercellular interactions in skeletal muscle development. This article reviews the molecular mechanisms of skeletal muscle development and its application value in animal husbandry breeding, and systematically combs the research progress, analysis processes, data resources, and future directions of single-cell omics, spatial omics, and single-cell spatial omics technology in skeletal muscle development. Among them, single-cell omics can reveal the heterogeneity of skeletal muscle cells, myofiber differentiation trajectories in different livestock and poultry (such as cattle, pigs, and Tibetan chickens) through methods like pseudotime analysis and RNA velocity analysis. Furthermore, single-cell omics can identify key transcription factors (e.g., MYF5, MYOD1) and cell communication pathways (e.g., FGF7-FGFR2), and simultaneously clarify the molecular differences in myoblast differentiation timing and cell composition ratio among different breeds. Relying on technologies such as Visium and Seq-Scope, spatial omics realizes the spatial localization of gene expression in pathological models of mice, Atlantic salmon, and broiler chickens. Spatial omics also clarifies the spatial distribution laws of neuromuscular junction region-specific genes and inflammation-fibrosis cascade reactions, and makes up for the defect of losing spatial context in single-cell technology. Although there are limited direct application cases of single-cell spatial omics technology, it has already analyzed the abnormal fate of myoblasts in facioscapulohumeral muscular dystrophy through MERFISH technology. In terms of technology selection, it is necessary to consider research objectives, molecular modalities, and resolution requirements. At the same time, data analysis needs to address challenges such as data sparsity through methods like DCA denoising and RCTD cell type mapping. In addition, this article summarizes 16 muscle development-related databases including HCA and PanglaoDB. This review further discusses the potential applications of these three types of technologies in the directional regulation of myoblast fate, precise intervention in the growth cycle, improvement of microenvironment interactions, and the development of multi-omics genetic breeding models. This paper is providing a more comprehensive and detailed theoretical reference and technical support for basic research on skeletal muscle development and practical applications in the animal husbandry industry.
