Transcriptomic analysis of muscle and adipose tissues identifies myokines and adipokines contributing to lipid deposition in Taoyuan Black pigs

Figures

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  Fig. 1. Cross-sectional area of adipocytes in subcutaneous, abdominal, and perirenal fat tissues. (A) Adipocyte area (μm2). (B) H&E staining of subcutaneous fat tissue (n = 3, magnification 10×). (C) Adipocyte area (μm2). (D) H&E staining of abdominal fat tissue (n = 3, magnification 10×). (E) Adipocyte area (μm2). (F) H&E staining of perirenal fat tissue (n = 3, magnification 10×). Data are presented as mean ± SD. Five fields per sample were used for statistical analysis. Asterisks (∗, ∗∗, ∗∗∗) mean significant difference between TB and Duroc pigs at the same age analyzed by t-test (P < 0.05, P < 0.01, P < 0.001, respectively). TB = Taoyuan Black pig; Duroc = Duroc pig.

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  Fig. 2. Myofiber type composition and morphological analysis of LD muscle. (A) Cross-sectional area (μm2) of myofibers. (B) H&E staining of LD muscle (n = 3, magnification 20×). Proportion of (C) Type 1 myofiber, (D) Type 2a myofiber, and (E) Type 2x myofiber of LD muscle. (F) IF staining of LD muscle (red, MYH7; pink, MYH2; green MYH1, n = 3, magnification 10×). Asterisks (∗, ∗∗, ∗∗∗) mean significant difference between TB and Duroc pigs at the same age analyzed by t-test (P < 0.05, P < 0.01, P < 0.001, respectively). LD muscle = longissimus dorsi muscle; TB = Taoyuan Black pig; Duroc = Duroc pig; MYH7 = myosin heavy chain 7; MYH2 = myosin heavy chain 2; MYH1 = myosin heavy chain 1.

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  Fig. 3. Gene set enrichment analysis of LD muscle and subcutaneous fat tissues in TB pigs between 180 and 120 d. (A) Top 15 significant GSEA pathway of LD muscle. GSEA in (B) PPAR signaling pathway, (C) pyruvate metabolism, (D) fatty acid metabolism, (E) biosynthesis of unsaturated fatty acids, and (F) insulin resistance of LD muscle. (G) Top 15 significant GSEA pathway of subcutaneous fat. GSEA in (H) fatty acid metabolism, (I) fatty acid degradation, (J) PPAR signaling pathway, (K) fatty acid biosynthesis, and (L) biosynthesis of unsaturated fatty acids of subcutaneous fat. At the bottom of each panel shows a heatmap of representative genes found within the leading edge-subset of the biological pathway. The color represents gene expression (FPKM) calibrated by z-core (n = 5). LD muscle = longissimus dorsi muscle; GSEA = gene set enrichment analysis; KEGG = Kyoto Encyclopedia of Genes and Genomes; NES = normalized enrichment score. The full names of genes are shown in Table S1.

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  Fig. 4. Change of secretory expression profile of LD muscle and subcutaneous fat tissues in TB pigs between 180 and 120 d. (A) GO enrichment of DEGs of LD muscle and subcutaneous fat related to extracellular. The number of secretory DEGs in (B) LD muscle and (C) subcutaneous fat. Heatmap of secretory DEGs in (D) LD muscle and (E) subcutaneous fat. The pseudocolor scaling of the heatmap is based on the gene expression (FPKM) calibrated by z-core, each row represents a gene, and each column represents a sample (n = 5). Correlation analysis of lipid deposition phenotypic data and secretory DEGs in (F) LD muscle, (G) subcutaneous fat (upregulated), and (H) subcutaneous fat (downregulated). The pseudocolor scaling of the heatmap is based on the correlation coefficient (cor) between genes and phenotypic data. Each row represents a single gene, and each column represents IMF (%), fat percentage (%), backfat thickness (mm), and perirenal fat percentage (%), Asterisks (∗, ∗∗) mean significant correlation (P < 0.05, P < 0.01, respectively). GO = gene ontology; DEGs = differentially expressed genes; LD muscle = longissimus dorsi muscle; FPKM = fragments per kilobase million; FC = fold change; IMF =…

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  Fig. 5. Serum content of myokines and adipokines correlated with lipid deposition. (A) Expression level (TPM) of IGF2 in LD muscle and subcutaneous fat tissues (n = 5). (B) Serum IGF2 content of TB and Duroc pigs at 120 and 180 d (n = 6). (C) Linear fitting and correlation analysis between serum IGF2 with lipid deposition of TB and Duroc pigs at 180 d. Significant correlation (P < 0.05) and correlation coefficient (R) analyzed by simple linear regression (Pearson). (D) Expression level (TPM) of SFRP5 in LD muscle and subcutaneous fat tissues (n = 5). (E) Serum SFRP5 content of TB and Duroc pigs at 120 and 180 d (n = 6). (F) Expression level (TPM) of AGT in LD muscle and subcutaneous fat tissues (n = 5). (G) Serum AGT content of TB and Duroc pigs at 120 and 180 d (n = 3). (H) Western blot of serum AGT in TB and Duroc pigs at 120 and 180 d (n = 3). Data are presented as mean ± SD. Asterisks (∗, ∗∗) mean significant differences between 180 and 120 d analyzed by t-test (P < 0.05, P < 0.01, respectively). Asterisks (∗) means a significant difference between the two breeds and ages analyzed by Two-way ANOVA (P < 0.05). TB = Taoyuan Black pig; Duroc = Duroc pig; LD muscle = longissimus dorsi…