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The genomic architecture of resistance to Campylobacter jejuni intestinal colonisation in chickens.

Psifidi A, Fife M, Howell J, Matika O, van Diemen PM, Kuo R, Smith J, Hocking PM, Salmon N, Jones MA, Hume DA, Banos G, Stevens MP, Kaiser P - BMC Genomics (2016)

Bottom Line: The level of colonisation with Campylobacter jejuni following experimental infection was found to be a quantitative trait.Finally, gene expression analyses were performed for some of the candidate resistance genes to support the results.Two of the QTLs for Campylobacter resistance are co-located with Salmonella resistance loci, indicating that it may be possible to breed simultaneously for enhanced resistance to both zoonoses.

View Article: PubMed Central - PubMed

Affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK. Androniki.psifidi@roslin.ed.ac.uk.

ABSTRACT

Background: Campylobacter is the leading cause of foodborne diarrhoeal illness in humans and is mostly acquired from consumption or handling of contaminated poultry meat. In the absence of effective licensed vaccines and inhibitors, selection for chickens with increased resistance to Campylobacter could potentially reduce its subsequent entry into the food chain. Campylobacter intestinal colonisation levels are influenced by the host genetics of the chicken. In the present study, two chicken populations were used to investigate the genetic architecture of avian resistance to colonisation: (i) a back-cross of two White Leghorn derived inbred lines [(61 x N) x N] known to differ in resistance to Campylobacter colonisation and (ii) a 9(th) generation advanced intercross (61 x N) line.

Results: The level of colonisation with Campylobacter jejuni following experimental infection was found to be a quantitative trait. A back-cross experiment using 1,243 fully informative single nucleotide polymorphism (SNP) markers revealed quantitative trait loci (QTL) on chromosomes 7, 11 and 14. In the advanced intercross line study, the location of the QTL on chromosome 14 was confirmed and refined and two new QTLs were identified located on chromosomes 4 and 16. Pathway and re-sequencing data analysis of the genes located in the QTL candidate regions identified potential pathways, networks and candidate resistance genes. Finally, gene expression analyses were performed for some of the candidate resistance genes to support the results.

Conclusion: Campylobacter resistance in chickens is a complex trait, possibly involving the Major Histocompatibility Complex, innate and adaptive immune responses, cadherins and other factors. Two of the QTLs for Campylobacter resistance are co-located with Salmonella resistance loci, indicating that it may be possible to breed simultaneously for enhanced resistance to both zoonoses.

No MeSH data available.


Related in: MedlinePlus

F-statistic scores obtained from least-squares interval mapping analysis in the back-cross experiment. F-statistic score of log-transformed number of C. jejuni per gram of caecal contents is plotted against location for chromosome 7 (above) and chromosome 14 (below)
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Fig1: F-statistic scores obtained from least-squares interval mapping analysis in the back-cross experiment. F-statistic score of log-transformed number of C. jejuni per gram of caecal contents is plotted against location for chromosome 7 (above) and chromosome 14 (below)

Mentions: The back-cross genotypes were analysed both using interval mapping (linkage analysis) and GWAS analysis (linkage disequilibrium (LD) analysis). In contrast to earlier studies [22, 23] we found with both analyses that levels of bacteria measured in challenged birds behaved as a quantitative trait, and mapped genetically to multiple loci. Two QTLs were detected on chromosomes 7 and 14 that were significantly associated with the log-transformed number of C. jejuni in the caeca at 5 dpi by the interval mapping analysis. The QTL on chromosome 7 was located at 26 Mb (Fig. 1) with a 1-LOD interval of 19.3 to 27.12 Mb. This QTL was significant at the chromosome-wide level (P-value <0.01) and, with an F value of 12.79, was close to genome-wide significance (5 % F-statistic threshold = 14.73). The QTL on chromosome 14 at 7 Mb (1 LOD interval 2.46 to 13.25 Mb) was significant at the chromosome-wide level (P-value <0.05) with an F value of 7.59 (Fig. 1).Fig. 1


The genomic architecture of resistance to Campylobacter jejuni intestinal colonisation in chickens.

Psifidi A, Fife M, Howell J, Matika O, van Diemen PM, Kuo R, Smith J, Hocking PM, Salmon N, Jones MA, Hume DA, Banos G, Stevens MP, Kaiser P - BMC Genomics (2016)

F-statistic scores obtained from least-squares interval mapping analysis in the back-cross experiment. F-statistic score of log-transformed number of C. jejuni per gram of caecal contents is plotted against location for chromosome 7 (above) and chromosome 14 (below)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4835825&req=5

Fig1: F-statistic scores obtained from least-squares interval mapping analysis in the back-cross experiment. F-statistic score of log-transformed number of C. jejuni per gram of caecal contents is plotted against location for chromosome 7 (above) and chromosome 14 (below)
Mentions: The back-cross genotypes were analysed both using interval mapping (linkage analysis) and GWAS analysis (linkage disequilibrium (LD) analysis). In contrast to earlier studies [22, 23] we found with both analyses that levels of bacteria measured in challenged birds behaved as a quantitative trait, and mapped genetically to multiple loci. Two QTLs were detected on chromosomes 7 and 14 that were significantly associated with the log-transformed number of C. jejuni in the caeca at 5 dpi by the interval mapping analysis. The QTL on chromosome 7 was located at 26 Mb (Fig. 1) with a 1-LOD interval of 19.3 to 27.12 Mb. This QTL was significant at the chromosome-wide level (P-value <0.01) and, with an F value of 12.79, was close to genome-wide significance (5 % F-statistic threshold = 14.73). The QTL on chromosome 14 at 7 Mb (1 LOD interval 2.46 to 13.25 Mb) was significant at the chromosome-wide level (P-value <0.05) with an F value of 7.59 (Fig. 1).Fig. 1

Bottom Line: The level of colonisation with Campylobacter jejuni following experimental infection was found to be a quantitative trait.Finally, gene expression analyses were performed for some of the candidate resistance genes to support the results.Two of the QTLs for Campylobacter resistance are co-located with Salmonella resistance loci, indicating that it may be possible to breed simultaneously for enhanced resistance to both zoonoses.

View Article: PubMed Central - PubMed

Affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK. Androniki.psifidi@roslin.ed.ac.uk.

ABSTRACT

Background: Campylobacter is the leading cause of foodborne diarrhoeal illness in humans and is mostly acquired from consumption or handling of contaminated poultry meat. In the absence of effective licensed vaccines and inhibitors, selection for chickens with increased resistance to Campylobacter could potentially reduce its subsequent entry into the food chain. Campylobacter intestinal colonisation levels are influenced by the host genetics of the chicken. In the present study, two chicken populations were used to investigate the genetic architecture of avian resistance to colonisation: (i) a back-cross of two White Leghorn derived inbred lines [(61 x N) x N] known to differ in resistance to Campylobacter colonisation and (ii) a 9(th) generation advanced intercross (61 x N) line.

Results: The level of colonisation with Campylobacter jejuni following experimental infection was found to be a quantitative trait. A back-cross experiment using 1,243 fully informative single nucleotide polymorphism (SNP) markers revealed quantitative trait loci (QTL) on chromosomes 7, 11 and 14. In the advanced intercross line study, the location of the QTL on chromosome 14 was confirmed and refined and two new QTLs were identified located on chromosomes 4 and 16. Pathway and re-sequencing data analysis of the genes located in the QTL candidate regions identified potential pathways, networks and candidate resistance genes. Finally, gene expression analyses were performed for some of the candidate resistance genes to support the results.

Conclusion: Campylobacter resistance in chickens is a complex trait, possibly involving the Major Histocompatibility Complex, innate and adaptive immune responses, cadherins and other factors. Two of the QTLs for Campylobacter resistance are co-located with Salmonella resistance loci, indicating that it may be possible to breed simultaneously for enhanced resistance to both zoonoses.

No MeSH data available.


Related in: MedlinePlus