Projet de thèse en Sciences agronomiques
Sous la direction de Michèle Tixier-boichard et de Chih-Feng Chen.
Thèses en préparation à Paris Saclay en cotutelle avec National Chung Hsing University , dans le cadre de École doctorale Agriculture, Alimentation, Biologie, Environnement, Santé (2015-.... ; Paris) , en partenariat avec GABI - Génétique animale et Biologie intégrative - UMR INRA/AgroParisTech/CEA (laboratoire) , Populations, statistiques et Génome (PSGen) (equipe de recherche) et de AgroParisTech (France) (établissement opérateur d'inscription) depuis le 01-11-2013 .
QTL mapping for economic traits in a cross between Taiwan country chickens and an experimental line of Rhode Island Red layers
High density genotyping in appropriate experimental designs makes possible to detect with a high accuracy genes underlying quantitative variation. The main objective of this thesis is to identify QTLs controlling variations of performance in chickens measured under humid tropical climate conditions. Recorded traits involve growth, immune response, egg laying, egg quality, and meat quality. A three-generation design was produced by crossing two unrelated parental lines of different origins: line R- is a Rhode Island Red population selected at INRA for low residual feed consumption; line L2 is a native line from Taiwan selected for body weight and high-egg production in National Chung-Hsing University which is used as a maternal line for the production of native chickens. Parental lines L2 and R- differed for most traits. Batch effect was generally significant. There were sex and MAT(mating type) effects on growth, immune response, meat, egg production and quality traits. The difference between XL and XR F2 groups suggested a possible influence of Z-linked inheritance on a few traits, such as comb area. Pearson correlation analysis showed moderate but significant relationships between body weight and immune traits, positive in males but negative in females. The highest correlations were observed between anatomical traits, egg shell color traits and between antibody titers for different antigens. Before running the QTL analysis, two further steps need to be done: traits which distribution deviates strongly from normality will be transformed; Mendelian inheritance of SNP genotypes will be checked. Then the QTL analysis will be performed by using genome-wide association study and linkage analysis (QTLMAP). Results will be compared with the data of chicken QTL database, and some regions will be chosen for further analysis in parental lines.