Signal relay in muscle growth

Gene expression is one of the main factors to influence meat quality by modulating fatty acid metabolism, composition, and deposition rates in muscle tissue. This study aimed to explore the transcriptomics of the Longissimus lumborum muscle in two local pig breeds with distinct genetic background using next-generation sequencing technology and Real-Time qPCR. RNA-seq yielded 49 differentially expressed genes between breeds, 34 overexpressed in the Alentejano (AL) and 15 in the Bísaro (BI) breed. Specific slow type myosin heavy chain components were associated with AL (MYH7) and BI (MYH3) pigs, while an overexpression of MAP3K14 in AL may be associated with their lower loin proportion, induced insulin resistance, and increased inflammatory response via NFkB activation. Overexpression of RUFY1 in AL pigs may explain the higher intramuscular (IMF) content via higher GLUT4 recruitment and consequently higher glucose uptake that can be stored as fat. Several candidate genes for lipid metabolism, excluded in the RNA-seq analysis due to low counts, such as ACLY, ADIPOQ, ELOVL6, LEP and ME1 were identified by qPCR as main gene factors defining the processes that influence meat composition and quality. These results agree with the fatter profile of the AL pig breed and adiponectin resistance can be postulated as responsible for the overexpression of MAP3K14′s coding product NIK, failing to restore insulin sensitivity.

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Function of the Porcine TRPC1 Gene in Myogenesis and Muscle Growth

Cells ◽

10.3390/cells10010147 ◽

2021 ◽

Vol 10 (1) ◽

pp. 147

Author(s):

Yu Fu ◽

Peng Shang ◽

Bo Zhang ◽

Xiaolong Tian ◽

Ruixue Nie ◽

...

Keyword(s):

Transient Receptor Potential ◽

Growth Traits ◽

Expression Profiles ◽

Muscle Growth ◽

Receptor Potential ◽

Transient Receptor Potential Channel ◽

Nucleotide Polymorphisms ◽

Pig Breeds ◽

Muscle Tissues ◽

Transient Receptor

In animals, muscle growth is a quantitative trait controlled by multiple genes. Previously, we showed that the transient receptor potential channel 1 (TRPC1) gene was differentially expressed in muscle tissues between pig breeds with divergent growth traits base on RNA-seq. Here, we characterized TRPC1 expression profiles in different tissues and pig breeds and showed that TRPC1 was highly expressed in the muscle. We found two single nucleotide polymorphisms (SNPs) (C-1763T and C-1604T) in TRPC1 that could affect the promoter region activity and regulate pig growth rate. Functionally, we used RNAi and overexpression to illustrate that TRPC1 promotes myoblast proliferation, migration, differentiation, fusion, and muscle hypertrophy while inhibiting muscle degradation. These processes may be mediated by the activation of Wnt signaling pathways. Altogether, our results revealed that TRPC1 might promote muscle growth and development and plays a key role in Wnt-mediated myogenesis.

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Key Genes Regulating Skeletal Muscle Development and Growth in Farm Animals

Animals ◽

10.3390/ani11030835 ◽

2021 ◽

Vol 11 (3) ◽

pp. 835

Author(s):

Mohammadreza Mohammadabadi ◽

Farhad Bordbar ◽

Just Jensen ◽

Min Du ◽

Wei Guo

Keyword(s):

Skeletal Muscle ◽

Candidate Genes ◽

Meat Quality ◽

Muscle Development ◽

Muscle Growth ◽

Farm Animals ◽

Meat Production ◽

Skeletal Muscle Development ◽

Extrinsic Factors ◽

Myogenic Regulatory Factor

Farm-animal species play crucial roles in satisfying demands for meat on a global scale, and they are genetically being developed to enhance the efficiency of meat production. In particular, one of the important breeders’ aims is to increase skeletal muscle growth in farm animals. The enhancement of muscle development and growth is crucial to meet consumers’ demands regarding meat quality. Fetal skeletal muscle development involves myogenesis (with myoblast proliferation, differentiation, and fusion), fibrogenesis, and adipogenesis. Typically, myogenesis is regulated by a convoluted network of intrinsic and extrinsic factors monitored by myogenic regulatory factor genes in two or three phases, as well as genes that code for kinases. Marker-assisted selection relies on candidate genes related positively or negatively to muscle development and can be a strong supplement to classical selection strategies in farm animals. This comprehensive review covers important (candidate) genes that regulate muscle development and growth in farm animals (cattle, sheep, chicken, and pig). The identification of these genes is an important step toward the goal of increasing meat yields and improves meat quality.

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PSIX-29 JAK2-STAT3 Pathway Mediated Satellite Cell Apoptosis to Govern Skeletal Muscle Growth with Lysine

Journal of Animal Science ◽

10.1093/jas/skaa278.594 ◽

2020 ◽

Vol 98 (Supplement_4) ◽

pp. 334-334

Author(s):

Zhi-wen Song ◽

Cheng-long Jin ◽

Mao Ye ◽

Chun-qi Gao ◽

Hui-chao Yan ◽

...

Keyword(s):

Skeletal Muscle ◽

Muscle Growth ◽

Longissimus Dorsi ◽

Control Group ◽

Stat3 Pathway ◽

Skeletal Muscle Growth ◽

Longissimus Dorsi Muscle ◽

Dorsi Muscle ◽

Pathway Inhibition ◽

Induced Apoptosis

Abstract Apoptosis is programmed cell death that can be stimulated by external stress or nutrition restrictions. Lysine (Lys) is an essential amino acid for pig growth, and the relationship between Lys deficiency caused apoptosis and inhibition of skeletal muscle growth remains unknown. The objective of this study was to investigate whether apoptosis could be regulated by Lys supplementation and the potential mechanism. In current work, 30 male Duroc × Landrace × Large weaned piglets were divided randomly into 3 groups: control group (Lys 1.30%), Lys deficiency group (Lys 0.86%), and Lys rescue group (Lys 0.86%, 0-14d; 1.30%,15–28 d). The experiment lasted for 28 days, and on the morning of 29 d, piglets were slaughtered to collect samples. Isobaric tag for relative and absolute quantification (iTRAQ) proteomics analysis of the longissimus dorsi muscle showed that Janus family tyrosine kinase (JAK)-signal transducer and activator of transcription (STAT) pathway was involved in Lys deficiency-induced apoptosis and inhibited skeletal muscle growth. Meanwhile, western blotting results of the longissimus dorsi muscle demonstrated that Lys deficiency caused apoptosis (P < 0.05) with the JAK2-STAT3 pathway inhibition (P < 0.05). Interestingly, apoptosis was suppressed (P < 0.05), and the JAK2-STAT3 pathway was reactivated (P < 0.05) after Lys re-supplementation in longissimus dorsi muscle. In addition, results of satellite cells (SCs) isolated from the longissimus dorsi muscle of 5-day-old Landrace piglets showed that Lys deficiency-induced apoptosis (P < 0.05) was mediated by the JAK2-STAT3 pathway inhibition (P < 0.05). Moreover, the JAK2-STAT3 pathway was reactivated (P < 0.05) by Lys re-supplementation and suppressed apoptosis in SCs (P < 0.05), and this effect was blocked (P < 0.05) after SCs treated with AG-490 (a specific inhibitor of JAK2). Collectively, Lys inhibited apoptosis in SCs to govern skeletal muscle growth via the JAK2-STAT3 pathway.

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