Detection of a Cis eQTL Controlling BMCO1 Gene Expression Leads to the Identification of a QTG for Chicken Breast Meat Color

Classical quantitative trait loci (QTL) analysis and gene expression QTL (eQTL) were combined to identify the causal gene (or QTG) underlying a highly significant QTL controlling the variation of breast meat color in a F2 cross between divergent high-growth (HG) and low-growth (LG) chicken lines. Within this meat quality QTL, BCMO1 (Accession number GenBank: AJ271386), encoding the β-carotene 15, 15′-monooxygenase, a key enzyme in the conversion of β-carotene into colorless retinal, was a good functional candidate. Analysis of the abundance of BCMO1 mRNA in breast muscle of the HG x LG F2 population allowed for the identification of a strong cis eQTL. Moreover, reevaluation of the color QTL taking BCMO1 mRNA levels as a covariate indicated that BCMO1 mRNA levels entirely explained the variations in meat color. Two fully-linked single nucleotide polymorphisms (SNP) located within the proximal promoter of BCMO1 gene were identified. Haplotype substitution resulted in a marked difference in BCMO1 promoter activity in vitro. The association study in the F2 population revealed a three-fold difference in BCMO1 expression leading to a difference of 1 standard deviation in yellow color between the homozygous birds at this haplotype. This difference in meat yellow color was fully consistent with the difference in carotenoid content (i.e. lutein and zeaxanthin) evidenced between the two alternative haplotypes. A significant association between the haplotype, the level of BCMO1 expression and the yellow color of the meat was also recovered in an unrelated commercial broiler population. The mutation could be of economic importance for poultry production by making possible a gene-assisted selection for color, a determining aspect of meat quality. Moreover, this natural genetic diversity constitutes a new model for the study of β-carotene metabolism which may act upon diverse biological processes as precursor of the vitamin A

Tissue Resources for the Functional Annotation of Animal Genomes

In order to generate an atlas of the functional elements driving genome expression in domestic animals, the Functional Annotation of Animal Genome (FAANG) strategy was to sample many tissues from a few animals of different species, sexes, ages, and production stages. This article presents the collection of tissue samples for four species produced by two pilot projects, at INRAE (National Research Institute for Agriculture, Food and Environment) and the University of California, Davis. There were three mammals (cattle, goat, and pig) and one bird (chicken). It describes the metadata characterizing these reference sets (1) for animals with origin and selection history, physiological status, and environmental conditions; (2) for samples with collection site and tissue/cell processing; (3) for quality control; and (4) for storage and further distribution. Three sets are identified: set 1 comprises tissues for which collection can be standardized and for which representative aliquots can be easily distributed (liver, spleen, lung, heart, fat depot, skin, muscle, and peripheral blood mononuclear cells); set 2 comprises tissues requiring special protocols because of their cellular heterogeneity (brain, digestive tract, secretory organs, gonads and gametes, reproductive tract, immune tissues, cartilage); set 3 comprises specific cell preparations (immune cells, tracheal epithelial cells). Dedicated sampling protocols were established and uploaded in https://data.faang.org/protocol/samples. Specificities between mammals and chicken are described when relevant. A total of 73 different tissues or tissue sections were collected, and 21 are common to the four species. Having a common set of tissues will facilitate the transfer of knowledge within and between species and will contribute to decrease animal experimentation. Combining data on the same samples will facilitate data integration. Quality control was performed on some tissues with RNA extraction and RNA quality control. More than 5,000 samples have been stored with unique identifiers, and more than 4,000 were uploaded onto the Biosamples database, provided that standard ontologies were available to describe the sample. Many tissues have already been used to implement FAANG assays, with published results. All samples are available without restriction for further assays. The requesting procedure is described. Members of FAANG are encouraged to apply a range of molecular assays to characterize the functional status of collected samples and share their results, in line with the FAIR (Findable, Accessible, Interoperable, and Reusable) data principles

A simple PCR method for sexing Japanese quail Coturnix japonica at hatching

A simple PCR method for sexing Japanese quail Coturnix japonica at hatchin

La viande de dindes reproductrices est-elle si différente de celle de dindes standards ?

National audienceThe technological, nutritional and sensorial quality of breast meat from turkey male and female breeders was characterized by comparison with breast meat from growing male and female turkeys of Grademaker line (Hybrid Turkeys) and analyzing 20 birds per sex and per physiological stage. The turkey breeders were slaughtered at 397 and 410 days of age and 10.42 and 32.67 kg of body weight for the females and males, respectively. The growing turkeys (standard birds) were slaughtered at 75 and 103 days of age and 5.89 and 13.48 kg of body weight for the females and males, respectively. The differences observed between males and females on one hand and between standard and breeder turkeys on the other hand were mainly induced by differences in slaughter ages and sexual dimorphism on body weight. The meat of female breeders had characteristics close to those of female and male standard turkeys whereas the meat of male breeders was clearly distinguishable particularly by displaying lower tenderness and water holding capacity.La qualité technologique, nutritionnelle et sensorielle des filets de dindes et dindons reproducteurs a été caractérisée par comparaison avec des filets de dindes et dindons standards de souche Grademaker (Hybrid Turkeys) avec un effectif de 20 animaux par sexe et par stade physiologique. Les animaux reproducteurs ont été abattus aux âges de 397 et 410 jours et aux poids de 10,42 et 32,67 kg pour les femelles et les mâles, respectivement. Les animaux en croissance (dindes de type standard) ont été abattus aux âges de 75 et 103 jours et aux poids de 5,89 et 13,48 kg pour les femelles et les mâles, respectivement. Les différences observées entre mâles et femelles d’une part et entre animaux standards et reproducteurs d’autre part sont essentiellement dues aux différences d’âges à l’abattage et au dimorphisme sexuel sur le poids vif. La viande de dindes reproductrices présente des caractéristiques très proches de celles des dindes et dindons standards alors que la viande des dindons reproducteurs se distingue nettement en présentant, en particulier, une texture plus ferme et un pouvoir de rétention en eau moins élevé

Impact of dietary phosphorus and calcium feeding strategies on intestinal gene expression of broilers

International audienc

Caractérisation phénotypique et métabolique précoce de poussins issus d'une sélection divergente sélectionnée sur le pH ultime de la viande

In chicken, the ultimate pH (pHu) of meat is largely determined by the muscle glycogen content at slaughter age.A divergent selection on the Pectoralis major pHu allowed the creation of the pHu+ and pHu- lines, whichrepresent a unique model for studying the genetic and physiological control of energy reserves and the meatquality. Several characteristics have been measured in the two lines at hatch then at 5 days of age: animal weight,muscle yields, muscular and hepatic glycogen content and several plasma parameters. At hatch, the pHu+ andpHu- lines present equivalent body weights and muscle yields. However, the pHu- line shows a higher glycemiathan the pHu+ line, a difference that will persist until the slaughter age. In addition, primary myoblasts culturesfrom both lines show differences in insulin response. After 5 days, the pHu+ and pHu- lines are alreadydivergent in terms of glycogen (and pHu) and muscle yield, for a similar body weight. Differences between bothlines observed at hatch and at 5 days may have been associated with regulation of signaling pathways involvedin protein synthesis and muscle glycogen turnover. In conclusion, pHu+ and pHu- chicks already have at hatchthe ability to respond differently to nutrients and hormones consistent with the fact that after only 5 days offeeding, significant differences in yield and muscular glycogen contents exist between the two lines.Chez le poulet, le pH ultime (pHu) de la viande est en grande partie déterminé par la teneur en glycogène dumuscle à l'abattage. Une sélection divergente sur le pHu du filet a permis la création des lignées pHu+ et pHu-,qui représentent un modèle unique pour étudier le contrôle génétique et physiologique des réserves énergétiqueset de la qualité de la viande. Plusieurs caractéristiques ont été mesurées dans les deux lignées à l’éclosion puis à5 jours d’âge: le poids vif, les rendements en muscles, le glycogène musculaire et hépatique et plusieursparamètres plasmatiques. A l’éclosion, les lignées pHu+ et pHu- présentent des poids vifs et des rendementsmusculaires équivalents. Toutefois, la lignée pHu- présente une glycémie supérieure à celle de la lignée pHu+,différence qui va persister jusqu'à l'âge d’abattage. Par ailleurs, les cultures primaires des myoblastes issues desdeux lignées révèlent des différences de réponse à l'insuline. Après 5 jours, les lignées pHu+ et pHu- sont déjàdivergentes en terme de glycogène (et de pHu) et de rendement en muscle, pour un poids vif similaire. Lesdifférences entre lignées observées à l'éclosion et à 5 jours ont pu être associées à des régulations au niveau desvoies de signalisation impliquées dans la synthèse protéique et le turn-over du glycogène musculaire. Enconclusion, les poussins pHu+ et pHu- présentent dès l’éclosion des capacités de réponses différentes auxnutriments et aux hormones cohérentes avec le fait qu’après seulement 5 jours d’alimentation, des différencessignificatives de rendement et de teneur en glycogène musculaire existent entre les deux lignées

Expression of glucose transporters <em>SLC2A1</em>, <em>SLC2A8</em>, and <em>SLC2A12</em> in different chicken muscles during ontogenesis

International audienceGlucose transport into cells is the first limiting step for the regulation of glucose homeostasis. In mammals, it is mediated by a family of facilitative glucose transporters (GLUTs) (encoded by SLC2A* genes), with a constitutive role (GLUT1), or insulin-sensitive transporters (GLUT4, GLUT8, and GLUT12). Compared to mammals, the chicken shows high levels of glycemia and relative insensitivity to exogenous insulin. To date, only GLUT1, GLUT8, and GLUT12 have been described in chicken skeletal muscles but not fully characterized, whereas GLUT4 was reported as lacking. The aim of the present study was to determine the changes in the expression of the SLC2A1, SLC2A8, and SLC2A12 genes, encoding GLUT1, GLUT8, and GLUT12 proteins respectively, during ontogenesis and how the respective expression of these three genes is affected by the muscle type and the nutritional or insulin status of the bird (fed, fasted, or insulin immunoneutralized). SLC2A1 was mostly expressed in the glycolytic pectoralis major (PM) muscle during embryogenesis and 5 d posthatching while SLC2A8 was mainly expressed at hatching. SLC2A12 expression increased regularly from 12 d in ovo up to 5 d posthatching. In the mixed-type sartorius muscle, the expression of SLC2A1 and SLC2A8 remained unchanged, whereas that of SLC2A12 was gradually increased during early muscle development. The expression of SLC2A1 and SLC2A8 was greater in oxidative and oxidoglycolytic muscles than in glycolytic muscles. The expression of SLC2A12 differed considerably between muscles but not necessarily in relation to muscle contractile or metabolic type. The expression of SLC2A1, SLC2A8, and SLC2A12 was reduced by fasting and insulin immunoneutralization in the PM muscle, while in the leg muscles only SLC2A12 was impaired by insulin immunoneutralization. Our findings clearly indicate differential regulation of the expression of three major GLUTs in skeletal muscles, with some type-related features. They provide new insights to improve the understanding of the fine regulation of glucose utilization in chicken muscles

Molecular Phenotyping of White Striping and Wooden Breast Myopathies in Chicken

International audienceThe White Striping (WS) and Wooden Breast (WB) defects are two myopathic syndromes whose occurrence has recently increased in modern fast-growing broilers. The impact of these defects on the quality of breast meat is very important, as they greatly affect its visual aspect, nutritional value, and processing yields. The research conducted to date has improved our knowledge of the biological processes involved in their occurrence, but no solution has been identified so far to significantly reduce their incidence without affecting growing performance of broilers. This study aims to follow the evolution of molecular phenotypes in relation to both fast-growing rate and the occurrence of defects in order to identify potential biomarkers for diagnostic purposes, but also to improve our understanding of physiological dysregulation involved in the occurrence of WS and WB. This has been achieved through enzymatic, histological, and transcriptional approaches by considering breast muscles from a slow- and a fast-growing line, affected or not by WS and WB. Fast-growing muscles produced more reactive oxygen species (ROS) than slow-growing ones, independently of WS and WB occurrence. Within fast-growing muscles, despite higher mitochondria density, muscles affected by WS or WB defects did not show higher cytochrome oxidase activity (COX) activity, suggesting altered mitochondrial function. Among the markers related to muscle remodeling and regeneration, immunohistochemical staining of FN1, NCAM, and MYH15 was higher in fast- compared to slow-growing muscles, and their amount also increased linearly with the presence and severity of WS and WB defects, making them potential biomarkers to assess accurately their presence and severity. Thanks to an innovative histological technique based on fluorescence intensity measurement, they can be rapidly quantified to estimate the injuries induced in case of WS and WB. The muscular expression of several other genes correlates also positively to the presence and severity of the defects like TGFB1 and CTGF, both involved in the development of connective tissue, or Twist1, known as an inhibitor of myogenesis. Finally, our results suggested that a balance between TGFB1 and PPARG would be essential for fibrosis or adiposis induction and therefore for determining WS and WB phenotypes

Molecular phenotyping of white striping and wooden breast defects

International audienc