Gene expression studies of developing bovine longissimus muscle from two different beef cattle breeds

Background: The muscle fiber number and fiber composition of muscle is largely determined during prenatal development. In order to discover genes that are involved in determining adult muscle phenotypes, we studied the gene expression profile of developing fetal bovine longissimus muscle from animals with two different genetic backgrounds using a bovine cDNA microarray. Fetal longissimus muscle was sampled at 4 stages of myogenesis and muscle maturation: primary myogenesis (d 60), secondary myogenesis (d 135), as well as beginning (d 195) and final stages (birth) of functional differentiation of muscle fibers. All fetuses and newborns (total n = 24) were from Hereford dams and crossed with either Wagyu (high intramuscular fat) or Piedmontese (GDF8 mutant) sires, genotypes that vary markedly in muscle and compositional characteristics later in postnatal life. Results: We obtained expression profiles of three individuals for each time point and genotype to allow comparisons across time and between sire breeds. Quantitative reverse transcription-PCR analysis of RNA from developing longissimus muscle was able to validate the differential expression patterns observed for a selection of differentially expressed genes, with one exception. We detected large-scale changes in temporal gene expression between the four developmental stages in genes coding for extracellular matrix and for muscle fiber structural and metabolic proteins. FSTL1 and IGFBP5 were two genes implicated in growth and differentiation that showed developmentally regulated expression levels in fetal muscle. An abundantly expressed gene with no functional annotation was found to be developmentally regulated in the same manner as muscle structural proteins. We also observed differences in gene expression profiles between the two different sire breeds. Wagyu-sired calves showed higher expression of fatty acid binding protein 5 (FABP5) RNA at birth. The developing longissimus muscle of fetuses carrying the Piedmontese mutation shows an emphasis on glycolytic muscle biochemistry and a large-scale up-regulation of the translational machinery at birth. We also document evidence for timing differences in differentiation events between the two breeds. Conclusion: Taken together, these findings provide a detailed description of molecular events accompanying skeletal muscle differentiation in the bovine, as well as gene expression differences that may underpin the phenotype differences between the two breeds. In addition, this study has highlighted a non-coding RNA, which is abundantly expressed and developmentally regulated in bovine fetal muscle

Asymmetric growth-limiting development of the female conceptus

IntroductionSex differences in prenatal growth may contribute to sex-dependent programming effects on postnatal phenotype. MethodsWe integrated for the first time phenotypic, histomorphological, clinico-chemical, endocrine and gene expression analyses in a single species, the bovine conceptus at mid-gestation. ResultsWe demonstrate that by mid-gestation, before the onset of accelerated growth, the female conceptus displays asymmetric lower growth compared to males. Female fetuses were smaller with lower ponderal index and organ weights than males. However, their brain:body weight, brain:liver weight and heart:body weight ratios were higher than in males, indicating brain and heart ‘sparing’. The female placenta weighed less and had lower volumes of trophoblast and fetal connective tissue than the male placenta. Female umbilical cord vessel diameters were smaller, and female-specific relationships of body weight and brain:liver weight ratios with cord vessel diameters indicated that the umbilico-placental vascular system creates a growth-limiting environment where blood flow is redistributed to protect brain and heart growth. Clinico-chemical indicators of liver perfusion support this female-specific growth-limiting phenotype, while lower insulin-like growth factor 2 (IGF2) gene expression in brain and heart, and lower circulating IGF2, implicate female-specific modulation of key endocrine mediators by nutrient supply. ConclusionThis mode of female development may increase resilience to environmental perturbations in utero and contribute to sex-bias in programming outcomes including susceptibility to non-communicable diseases

Evaluation of fatty acid metabolism and innate immunity interactions between commercial broiler, F1 layer × broiler cross and commercial layer strains selected for different growth potentials

Abstract Background The broiler industry has undergone intense genetic selection over the past 50 yr. resulting in improvements for growth and feed efficiency, however, significant variation remains for performance and growth traits. Production improvements have been coupled with unfavourable metabolic consequences, including immunological trade-offs for growth, and excess fat deposition. To determine whether interactions between fatty acid (FA) metabolism and innate immunity may be associated with performance variations commonly seen within commercial broiler flocks, total carcass lipid %, carcass and blood FA composition, as well as genes involved with FA metabolism, immunity and cellular stress were investigated in male birds of a broiler strain, layer strain and F1 layer × broiler cross at d 14 post hatch. Heterophil: lymphocyte ratios, relative organ weights and bodyweight data were also compared. Results Broiler bodyweight (n = 12) was four times that of layers (n = 12) by d 14 and had significantly higher carcass fat percentage compared to the cross (n = 6; P = 0.002) and layers (P = 0.017) which were not significantly different from each other (P = 0.523). The carcass and whole blood FA analysis revealed differences in the FA composition between the three groups indicating altered FA metabolism, despite all being raised on the same diet. Genes associated with FA synthesis and β-oxidation were upregulated in the broilers compared to the layers indicating a net overall increase in FA metabolism, which may be driven by the larger relative liver size as a percentage of bodyweight in the broilers. Genes involved in innate immunity such as TLR2 and TLR4, as well as organelle stress indicators ERN1 and XBP1 were found to be non-significant, with the exception of high expression levels of XBP1 in layers compared to the cross and broilers. Additionally there was no difference in heterophil: lymphocytes between any of the birds. Conclusions The results provide evidence that genetic selection may be associated with altered metabolic processes between broilers, layers and their F1 cross. Whilst there is no evidence of interactions between FA metabolism, innate immunity or cellular stress, further investigations at later time points as growth and fat deposition increase would provide useful information as to the effects of divergent selection on key metabolic and immunological processes

Correlations between intestinal innate immune genes and cecal microbiota highlight potential for probiotic development for immune modulation in poultry

Stanley, D ORCiD: 0000-0001-7019-4726Immune function is influenced by the diversity and stability of the intestinal microbiota. A likely trade-off of immune function for growth has been demonstrated in heavier breeds of poultry that have been genetically selected for growth and feed efficiency traits. We investigated the expression of selected innate immune genes and genes encoding products involved in intestinal barrier function to determine whether function changes could be consistently linked to the phenotypic expression of feed conversion ratio (FCR), a common measure of performance within poultry broiler flocks. In addition, we compared individual cecal microbial composition with innate immune gene expression. Samples were utilised from two replicate trials termed P1E1 and P1E2. High (n = 12) and low (n = 12) performing birds were selected based on their individual FCR data from each replicate and combined for microbiota phylogenetic composition and immune gene expression analysis. Toll-like receptor 1 (TLR1La) and zonula occludens 1 (ZO1) were differentially expressed between high- and low-performing broilers. Several taxa were correlated with FCR; of these, unclassified YS2 and ZO1 were also positively correlated with each other. Interactions between taxa and differentially expressed innate immune genes between P1E1 and P1E2 were much greater compared to relationships between high- and low-performing birds. At the level of phylum, reciprocal correlations between tight junction proteins and Toll-like receptors with Bacteroidetes and Firmicutes were evident, as were correlations at the genus level. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature

Effect of nutrition of oocyte donor on the outcomes of somatic cell nuclear transfer in the sheep

The purpose of this study was to determine if the nutrition of the oocyte donor ewe influenced the success of somatic cell cloning. Merino ewes were fed at either a high- or a low-nutrition level for 3-5 mo before superovulation treatments. Freshly ovulated oocytes were enucleated and fused with serum-starved adult granulosa cells, and resulting reconstructed embryos were cultured for 6 days in modified synthetic oviduct fluid. Embryo cleavage and development to blastocysts were recorded, and good-quality embryos were transferred to synchronized recipient ewes either fresh or, on a few occasions, after vitrification. Pregnancies were monitored by ultrasonography from Day 40 of pregnancy, and offspring were delivered by either cesarean section or vaginal delivery. No differences occurred in the numbers of follicles aspirated, of oocytes recovered, or of oocytes utilizable for cloning between the high and low groups. Neither were there treatment differences in development to the blastocyst stage. However, transfer of embryos from the high group led to significantly more pregnancies and implanted fetuses. Also, more of the established pregnancies from the high group were carried to term, although this difference was not statistically significant. Lamb mortality was high, with half the live-born perishing soon after birth and more succumbing to various infections within days or weeks of birth, but no clear association between the offspring fate and the treatment group could be established. These results suggest that more research into the effect of nutrition on oocyte quality and its subsequent effect on cloning is warranted

Gene expression studies of developing bovine muscle from two different beef cattle breeds-1

<p><b>Copyright information:</b></p><p>Taken from "Gene expression studies of developing bovine muscle from two different beef cattle breeds"</p><p>http://www.biomedcentral.com/1471-213X/7/95</p><p>BMC Developmental Biology 2007;7():95-95.</p><p>Published online 16 Aug 2007</p><p>PMCID:PMC2031903.</p><p></p> Wagyu (shaded) fetuses, comparing total and amplified RNA. The data represent average values and standard error measurements from 3 individual animal samples, normalized against ribosomal protein, large PO () expression measured in the same sample

Gene expression studies of developing bovine muscle from two different beef cattle breeds-2

<p><b>Copyright information:</b></p><p>Taken from "Gene expression studies of developing bovine muscle from two different beef cattle breeds"</p><p>http://www.biomedcentral.com/1471-213X/7/95</p><p>BMC Developmental Biology 2007;7():95-95.</p><p>Published online 16 Aug 2007</p><p>PMCID:PMC2031903.</p><p></p>of overrepresented gene ontology annotations in the differentially expressed gene lists (Tables 1 and 2). (A) Biological process annotation of genes which showed decreasing expression over the developmental time course. (B) Biological process annotation of genes which showed increasing expression over the developmental time course