@phdthesis{1ee668195c184f6f83962316f4f23ed9,
title = "Genetics of mechanisms controlling responses to two major pathogens in broiler and layer chickens",
abstract = "The objective of this thesis was to improve the understanding of molecular mechanisms controlling the response to two major pathogens, Eimeria maxima (coccidiosis) and infectious bronchitis virus (IBV), in broiler and layer chickens, respectively. Breeding for the improved response to the two pathogens is a possible complementary approach for their control in poultry production. A key step is to understand the molecular mechanisms controlling the host{\textquoteright}s response to a disease. For E. maxima, a large-scale challenge study on Cobb500 broilers and a follow-up genome-wide association study (GWAS) were performed, which aimed at evaluating the effects of the challenge on the measured parameters, then identifying genomic regions and biological pathways explaining variation of these parameters. Several candidate genes were identified after the performed GWAS. Moreover, biological pathways involved in tissue repair, general robustness and early immune response seem to play an important role during the initial stage of the infection. For IBV, an experimental infection was performed on two chicken lines which were divergently selected for low and high levels of serum mannose-binding lectin (MBL), respectively. MBL plays a key role in innate immunity which is crucial for improving disease resistance. We observed large differences in the immune parameters and the spleen transcriptome profiles for uninfected and IBV infected birds between the two MBL lines. The large differences in expression of genes involved in the adaptive cellular immune response, therefore the ability to respond to the infection, explain probably the contrasted viral loads observed between lines. These findings provide additional knowledge for both potential improvements of animal robustness to IBV infection as well as vaccine outcome.",
keywords = "IBV, coccidiosis, disease resistance, immunogenetics, GWAS, RNA-Seq, genetics, genomics, broiler, chicken, immunology, L10 line, annotation, collectins, MBL, ficolins",
author = "Edin Hamzic",
note = "PhD thesis",
year = "2016",
month = jan,
day = "8",
language = "English",
publisher = "Aarhus University, Science and Technology",
}