Skeletal muscle satellite cells (SMSCs) are quiescent stem cells located in skeletal muscle tissue and function as the primary reservoir of myogenic progenitors for muscle growth and regeneration. However, the molecular and metabolic mechanisms governing their differentiation in geese remain largely unexplored. This study comprehensively examined the morphological, transcriptional, and metabolic dynamics of goose SMSCs across three critical differentiation stages: the quiescent stage (DD0), the differentiation stage (DD4), and the late differentiation stage (DD6). By integrating transcriptomic and metabolomic analyses, stage-specific molecular signatures and regulatory networks involved in SMSC differentiation were identified. Principal component analysis revealed distinct clustering patterns in gene expression and metabolite profiles across these stages, highlighting dynamic shifts in lipid metabolism and myogenesis. The PPAR signaling pathway emerged as a key regulator, with crucial genes such as PPARG, IGF1, ACSL5, FABP5, and PLIN1 exhibiting differentiation-dependent expression patterns. Notably, PPARG and IGF1 displayed negative correlations with adenosine and L-carnitine levels, suggesting their role in metabolic reprogramming during myotube formation. Additionally, MYOM2 and MYBPC1 exhibited stage-specific regulation and positively correlated with 2,3-dimethoxyphenylamine. This study provides a foundational framework for understanding muscle development and regeneration, offering valuable insights for both agricultural and biomedical research.

Muscle development in goose embryos is a complex and highly coordinated process involving dynamic morphological and transcriptional changes. Skeletal muscle satellite cells (SMSCs) play essential roles in postnatal muscle growth, regeneration, and meat quality, yet the molecular mechanisms regulating SMSC behavior during embryonic development in geese remain incompletely characterized. In this study, we integrated histology, immunofluorescence, and transcriptomics to investigate leg muscle development and SMSC dynamics in female Zhedong White (ZW) geese at embryonic days 15, 18, and 23 (E15F, E18F, and E23F). Histological examination revealed progressive myofiber hypertrophy and alignment from E15F to E23F. Concurrently, the proportion of Pax7⁺ SMSCs progressively decreased, indicating the establishment of a quiescent satellite cell pool. RNA sequencing of SMSCs identified numerous differentially expressed genes across developmental stages. Transcriptomic profiling indicated a clear developmental transition: early stages (E15F) were enriched in genes related to structural and contractile proteins (e.g., MYL1, ACTC1, TNNT2), while later stages (E23F) were associated with upregulation of genes involved in lipid metabolism (e.g., PPARG, PLIN2, ACSL1), extracellular matrix remodeling (e.g., MMP2, SPP1), and signal transduction (e.g., FGF10, IGFBP5). Functional enrichment analysis further supported a shift from active myogenesis toward metabolic maturation and tissue reorganization. Protein-protein interaction network analysis identified a core regulatory module involving MEF2C, MEF2D, MYOD1, and MSTN. Key gene expression trends were confirmed by quantitative PCR. Together, these findings provide a comprehensive transcriptomic resource that delineates the stage-specific molecular programs guiding SMSC differentiation and functional maturation during embryonic myogenesis in geese.

Skeletal muscle satellite cells (SMSCs) are essential for embryonic myogenesis and postnatal muscle regeneration; however, their cellular heterogeneity and transcriptional dynamics during avian development remain largely unexplored. Here, we performed single-cell RNA sequencing (scRNA-seq) on 42,886 cells isolated from goose leg muscles across four embryonic stages (E13, E15, E18, and E23), with each stage comprising pooled tissues from four female embryos. Unbiased clustering resolved 22 transcriptionally distinct clusters representing six major cell types—satellite cells, myocytes, fibro-adipogenic progenitors, endothelial cells, immune cells, and Schwann cells—with satellite cells being the most abundant. Satellite cells were further subdivided into three functional states (quiescent, activated, and proliferative/differentiating), which followed a continuous, linear pseudotime trajectory from early to late embryonic stages. This trajectory was marked by a progressive downregulation of stemness-associated regulators (e.g., PAX7) and upregulation of myogenic commitment and differentiation factors (e.g., MYF5, MYOD1, and MYOG), faithfully mirroring chronological development. Cell–cell communication analysis revealed that quiescent satellite cells exhibited the most extensive intercellular signaling networks (e.g., FGFR, Ephrin, collagen, CADM), whereas activated and proliferative/differentiating cells showed progressively diminished communication capacity. Across developmental stages, the contribution intensities of key signaling pathways—including SEMA6, CDH, FGF, LAMININ, MK, MPZ, CADM, FN1, and COLLAGEN—varied significantly among satellite cell states, indicating state-specific responsiveness to microenvironmental cues. Collectively, these findings demonstrate that satellite cells dynamically coordinate extrinsic signal integration with intrinsic differentiation programs to achieve orderly myogenic progression. This study provides a high-resolution single-cell atlas of goose SMSC development, uncovering subpopulation heterogeneity, state-specific molecular signatures, and key signaling pathways, with important implications for avian muscle biology and genetic improvement of poultry.

Fasting and refeeding systems can cause significant short-term fluctuations in nutrient and energy levels, triggering adaptive physiological responses in animals. This study examines the effects of fasting and refeeding on blood biochemical indicators and transcriptional profiles in the hypothalamus and subcutaneous adipose tissue of geese. Biochemical assays reveal that fasting significantly increases levels of free fatty acids and glucagon, while reducing concentrations of triglycerides, leptin, and insulin. Transcriptomic analyses identify a complex transcriptional response in both the hypothalamus and subcutaneous adipose tissue, affecting several metabolic pathways and key genes associated with feed intake and energy metabolism. In subcutaneous adipose tissue, fasting downregulates genes involved in fatty acid synthesis (LPL, SCD, and ACSL1) and upregulates PLIN2, a gene promoting lipid droplet degradation. Fasting affects a variety of metabolic pathways and critical genes in the hypothalamus, including Apelin, insulin, and mTOR signaling pathways. After fasting, the mRNA expression of NOG, GABRD, and IGFBP-1 genes in the hypothalamus are significantly upregulated, while proopiomelanocortin (POMC) gene expression is markedly downregulated. This study highlights the intricate biological responses to nutritional changes in geese, which adds to our understanding of energy balance and metabolic regulation in avian species.

This study investigated a compound low-protein diet (CLPD) strategy to reduce soybean meal (SBM) dependency in meat geese. Diets were formulated with crude protein (CP) levels decreasing from 16.5% (corn-soybean meal diet, CSD) to 9.8%, incorporating alternative ingredients such as rapeseed meal, corn distillers dried grains with solubles (DDGS), broken rice, and rice bran. All diets were balanced for limiting amino acids (lysine, methionine, threonine, and valine) through supplemental synthetic amino acids. A total of 192 four-week-old Sanhua geese were randomly assigned according to a single-factor completely randomized design to four dietary treatment groups: the 16.5% (CSD) group and three CLPD treatment groups (14.0% CP, 11.5% CP, and 9.8% CP). Each treatment consisted of six replicate pens with eight geese per pen. During the six-week trial, evaluations included growth performance, organ weights, nutrient digestibility, serum biochemistry, amino acid profiles, intestinal morphology, and cecal microbiota composition. Results demonstrated that compared to the 16.5% (CSD) group, the 11.5% CP (CLPD) group significantly improved final body weight (p < 0.05), average daily gain (P_Linear < 0.01, p < 0.05), and feed conversion efficiency (P_Linear < 0.01, p < 0.05), alongside enhanced apparent digestibility of crude protein and amino acids (P_Linear < 0.01, p < 0.05). Organ weights were generally stable, though the 9.8% CP (CLPD) group showed reduced liver weight (p < 0.05) and increased abdominal fat (P_Linear < 0.01, p < 0.05). Serum levels of low-density lipoprotein cholesterol increased (P_Linear < 0.05, p < 0.05). Intestinal morphology improved in the duodenum and jejunum: in the duodenum, villus height and villus-to-crypt ratio were significantly increased, and crypt depth was significantly decreased (P_Linear < 0.01, p < 0.05); in the jejunum, villus height was significantly increased (p < 0.05) and crypt depth was significantly decreased (p < 0.05). Cecal microbiota alpha diversity remained consistent. The dominant genera in the 9.8% CP (CLPD) group were unclassified_Oscillospiraceae and unclassified_Ruminococcaceae (p < 0.05), among which, Megamonas, Prevotellaceae_Ga6A1_group, and Rikenellaceae_RC9_gut_group dominated in the 16.5% (CSD) group (p < 0.05). These findings indicate that a compound low-protein diet (CLPD) with 11.5% CP, precisely balanced for limiting amino acids, supports optimal growth performance, improves nutrient utilization, and maintains intestinal health in meat geese. Overall, this offers a viable approach to easing SBM reliance in poultry nutrition while enhancing resource efficiency.