Gene Expression Essential for Myostatin Signaling and Skeletal Muscle Development Is Associated With Divergent Feed Efficiency in Pedigree Male Broilers

Background: Feed efficiency (FE, gain to feed) is an important genetic trait as 70% of the cost of raising animals is due to feed costs. The objective of this study was to determine mRNA expression of genes involved in muscle development and hypertrophy, and the insulin receptor-signaling pathway in breast muscle associated with the phenotypic expression of FE.Methods: Breast muscle samples were obtained from Pedigree Male (PedM) broilers (8 to 10 week old) that had been individually phenotyped for FE between 6 and 7 week of age. The high FE group gained more weight but consumed the same amount of feed compared to the low FE group. Total RNA was extracted from breast muscle (n = 6 per group) and mRNA expression of target genes was determined by real-time quantitative PCR.Results: Targeted gene expression analysis in breast muscle of the high FE phenotype revealed that muscle development may be fostered in the high FE PedM phenotype by down-regulation several components of the myostatin signaling pathway genes combined with upregulation of genes that enhance muscle formation and growth. There was also evidence of genetic architecture that would foster muscle protein synthesis in the high FE phenotype. A clear indication of differences in insulin signaling between high and low FE phenotypes was not apparent in this study.Conclusion: These findings indicate that a gene expression architecture is present in breast muscle of PedM broilers exhibiting high FE that would support enhanced muscle development-differentiation as well as protein synthesis compared to PedM broilers exhibiting low FE

Celiac Blood Flow Regulation, Acid-Base Balance and Production in Heat-Stressed Cockerels (Cate Cholamines)

207 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1984.An acid-base disturbance characterized by reduced blood CO2 and H+ content developes in heat-stressed panting fowl. An acid-base imbalance could reduce productivity either by reducing metabolic efficiency or by depresing energy absorption by reducing gastrointestinal blood flow.Growth trails were performed to determine the effect of carbonated water (CW) on performance of heat-stressed cockerels. Compared to birds provided tap water (TW), CW improved average daily gain or feed efficiency in cockerels subjected to constant 33 C or to cyclic 29-34 C temmperatures, respectively. Cockerels infused with CW directly into the crop exhibited higher blood PCO2 and lower blood pH compared to TW infused cockerels after 90 min of heat stress.Next, studies were designed to elucidate the physiological basis of heat-induced celiac mean blood flow (MBF) reduction in fed cockerels chronically instrumented with electromagnetic blood flow probes. Heat stress reduced MBF by 50% compared to thermoneutral control values. MBF changes were highly correlated (-.83 to -.89) with celiac vascular resistance (CVR), but poorly correlated with blood PCO2 and pH. The nearly complete abolition of heat-induced celiac vasoconstriction by prior infusion of phenoxybenzamine clearly demonstrated sympathetic regulation of MBF during heat stress. Plasma samples obtained during heat stress were analyzed for epinephrine (E), norepinephrine (NE), and Dopamine (DA). Heat stress initially reduced E and NE and increased DA titer. NE remained depressed throughout heat stress but increasing E titer during the heat stress period was concomitant with increasing heart rate and rectal temperature. Contrary to accepted NE activity on intestinal smooth muscle vasculature, plasma NE was directly correlated (.93) with MBF and inversely correlated (-.96) with CVR.From these studies it was concluded that: (1) Heat-induced MBF reduction was due to sympathetic regulation, independent of blood PCO2 or pH changes. (2) Heat-induced celiac vasoconstriction was apparently due to local sympathetic release of catecholamines and not from changes in plasma catecholamine concentrations. (3) CW may increase growth or feed utilization by partially ameliorating the acid-base imbalance associated with heat stress.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Correction: Proteomics of Breast Muscle Tissue Associated with the Phenotypic Expression of Feed Efficiency within a Pedigree Male Broiler Line: I. Highlight on Mitochondria.

[This corrects the article DOI: 10.1371/journal.pone.0155679.]

Proteomics of breast muscle tissue associated with the phenotypic expression of feed efficiency within a pedigree male broiler line: I. Highlight on mitochondria

The fifth author's name is spelled incorrectly. The correct name is: Antonio Reverter. The correct citation is: Kong B-W, Lassiter K, Piekarski-Welsher A, Dridi S, Reverter A, Hudson NJ, et al. (2016) Proteomics of Breast Muscle Tissue Associated with the Phenotypic Expression of Feed Efficiency within a Pedigree Male Broiler Line: I. Highlight on Mitochondria. PLoS ONE 11(5): e0155679. doi:10.1371/journal.pone.0155679

The protein abundance for the difference (Minus [M] for high FE minus low FE) and protein abundance alone (A) for all proteins.

<p>The MA plot is consistent with a reduction in slow fiber subunits (TPM2, ACTC) in the high FE (HFE) and an increase in mitochondrial regulators of muscle energy supply in the form of ATP (SLC25A4) and creatine phosphate (VDAC2). GAPDH is the most abundant protein we identified. Further, the mitoproteome (highlighted in red, Fig 2A) is skewed towards the HFE consistent with a higher mitochondrial content. Highly differentially expressed proteins were identified by a metric called Phenotypic Impact Factor (PIF), with the extreme 10% highlighted in blue (Fig 2B). Abbreviations: (RTN4), reticulon 4; (PHKG1), phosphorylase kinase gamma 1; (SLC26A4), adenine nucleotide translocase 1; (ACTC), alpha actin cardiac; (Gga), golgi associated gamma adaptin; (GAPDH) glyceraldyhde 3-phosphate dehydrogenase; (TPM2), tropomyosin 2.</p

Upstream regulators predicted to be activated or inhibited in the proteomic dataset.

<p>Upstream regulators predicted to be activated or inhibited in the proteomic dataset.</p

SDS-PAGE gel electrophoresis in broiler breast muscle.

<p>Protein bands prior to protein extractions of breast muscle obtained from pedigree broiler breeder males exhibiting low feed efficiency (L) or high feed efficiency (H) (n = 4 per group). From this gel, a total of 25 slices were obtained and subjected to tryptic digestion prior to conducting shotgun proteomics.</p

Top canonical pathways.

<p>The top 6 canonical pathways (based on p value) generated by Ingenuity Pathway Analysis based on differentially expressed proteins in breast muscle obtained from broiler breeder males.</p

A hierarchically clustered heat map of the 40 most differentially expressed proteins as identified by PIF.

<p>Each cell contains the normalized expression of the protein at the individual bird level. Red denotes high expression, green denotes low expression. All 8 birds discriminate into their correct treatment group of origin (HFE or LFE) and relatedness within a group is also apparent. Proteins are clustered by patterns of co-expression across the 8 birds. Strong co-expression is observed for functionally related proteins e.g. ARF1 with ARF4 and KRT3 with KRT5 and KRT14 and the muscle structural proteins, namely TPM1, TPM2 and CAPZB. Different fragment of the same protein are highly co-expressed. Note: ‘B’ are birds with a low FE phenotype whereas ‘G’ are birds with a high FE phenotype. <b>Abbreviations:</b> (RTN4), reticulon 4; (NDUFV2), NADH dehydrogenase (ubiquinone) Fe-S protein 7; (PHKG1), phosphorylase kinase gamma 1; (IDE), insulin degrading enzyme; (CACNA15), calcium channel voltage dependent 1 L type, alpha 15; (ARF), ADP ribosylation factor 4 and 1; (SAR1B), SAR1-ADP ribosylation factor, (SPEG), striated muscle preferentially expressed protein; (Gga), golgi associated gamma adaptin; (RYR3) ryanodine receptor 3; (SLC26A4), adenine nucleotide translocase 1; (MYO18A), myosin 18A; (KRT), keratin; (TPM), tropomyosin; (BAT2), large proline rich protein; (CAPZB), F-actin capping protein subunit beta; (DCTN2), dynactin 2; (ACTA1), alpha actin 1; (GSN), gelsolin; (SMYD1), myosin interacting protein; (NEB), lambda protein phosphatase; (OIH) ovoinhibitor; (UBQLN), ubituilin family proteins</p