Genome-wide association studies of immune, disease and production traits in indigenous chicken ecotypes

Genetics Selection Evolution

Research Article

Rob Christley¹  Paul Wigley¹  Judy Bettridge¹  Tadelle Dessie²  Takele T. Desta³  Olivier Hanotte⁴  Pete Kaiser⁵  Oswald Matika⁵  Androniki Psifidi⁵  David A. Hume⁵  Georgios Banos⁶ 

[1] Institute of Infection and Global Health, University of Liverpool, Leahurst Campus, CH64 7TE, Liverpool, UK;International Livestock Research Institute, P.O. Box 5689, Addis Ababa, Ethiopia;School of Life Sciences, University of Nottingham, University Park, NG7 2RD, Nottingham, UK;School of Life Sciences, University of Nottingham, University Park, NG7 2RD, Nottingham, UK;International Livestock Research Institute, P.O. Box 5689, Addis Ababa, Ethiopia;The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, EH25 9RG, Midlothian, UK;The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, EH25 9RG, Midlothian, UK;Scotland’s Rural College, Easter Bush, EH25 9RG, Edinburgh, Midlothian, UK;

关键词: Major Histocompatibility Complex;    Antibody Titre;    Production Trait;    Body Condition Score;    Significant SNPs;   

DOI  :  10.1186/s12711-016-0252-7

 received in 2016-04-08, accepted in 2016-09-15,  发布年份 2016

来源: Springer

【 摘 要 】

BackgroundThe majority of chickens in sub-Saharan Africa are indigenous ecotypes, well adapted to the local environment and raised in scavenging production systems. Although they are generally resilient to disease challenge, routine vaccination and biosecurity measures are rarely applied and infectious diseases remain a major cause of mortality and reduced productivity. Management and genetic improvement programmes are hampered by lack of routine data recording. Selective breeding based on genomic technologies may provide the means to enhance sustainability. In this study, we investigated the genetic architecture of antibody response to four major infectious diseases [infectious bursal disease (IBDV), Marek’s disease (MDV), fowl typhoid (SG), fowl cholera (PM)] and resistance to Eimeria and cestode parasitism, along with two production traits [body weight and body condition score (BCS)] in two distinct indigenous Ethiopian chicken ecotypes. We conducted variance component analyses, genome-wide association studies, and pathway and selective sweep analyses.ResultsThe large majority of birds was found to have antibody titres for all pathogens and were infected with both parasites, suggesting almost universal exposure. We derived significant moderate to high heritabilities for IBDV, MDV and PM antibody titres, cestodes infestation, body weight and BCS. We identified single nucleotide polymorphisms (SNPs) with genome-wide significance for each trait. Based on these associations, we identified for each trait, pathways, networks and functional gene clusters that include plausible candidate genes. Selective sweep analyses revealed a locus on chromosome 18 associated with viral antibody titres and resistance to Eimeria parasitism that is within a positive selection signal. We found no significant genetic correlations between production, immune and disease traits, implying that selection for altered antibody response and/or disease resistance will not affect production.ConclusionsWe confirmed the presence of genetic variability and identified SNPs significantly associated with immune, disease and production traits in indigenous village chickens. Results underpin the feasibility of concomitant genetic improvement for enhanced antibody response, resistance to parasitism and productivity within and across indigenous chicken ecotypes.

【 授权许可】

CC BY   
© The Author(s) 2016

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