Identification of QTL affecting resistance/susceptibility to acute Actinobacillus pleuropneumoniae infection in swine.
Actinobacillus pleuropneumoniae is among the most important pathogens worldwide in pig production. The agent can cause severe economic losses due to decreased performance, acute or chronic pleuropneumonia and an increased incidence of death. Therapeutics cannot be used in a sustainable manner, and vaccination is not always available, but discovering more about host defence and disease mechanisms might lead to new methods of prophylaxis. The aim of the present study was to detect quantitative trait loci (QTL) associated with resistance/susceptibility to A. pleuropneumoniae. Under controlled conditions, 170 F2 animals of a Hampshire/Landrace family, with known differences in founder populations regarding A. pleuropneumoniae resistance, were challenged with an A. pleuropneumoniae serotype 7 aerosol followed by a detailed clinical, radiographic, ultrasonographic, pathological and bacteriological examination. F2 pigs were genotyped with 159 microsatellite markers. Significant QTL were identified on Sus scrofa chromosomes (SSC) 2, 6, 12, 13, 16, 17 and 18. They explained 6-22% of phenotypic variance. One QTL on SSC2 reached significance on a genome-wide level for five associated phenotypic traits. A multiple regression analysis revealed a combinatory effect of markers SWR345 (SSC2) and S0143 (SSC12) on Respiratory Health Score, Clinical Score and the occurrence of death. The results indicate the genetic background of A. pleuropneumoniae resistance in swine and provide new insights into the genetic architecture of resistance/susceptibility to porcine pleuropneumonia. The results will be helpful in identifying the underlying genes and mechanisms.
Department of Veterinary Clinical Sciences, Justus-Liebig-University, Frankfurter Strasse 112, 35392, Giessen, Germany, gerald.reiner@vetmed.uni-giessen.de.
Gerald
G
Reiner
Natalie
N
Bertsch
Doris
D
Hoeltig
Martin
M
Selke
Hermann
H
Willems
Gerald Friedrich
GF
Gerlach
Burkhard
B
Tuemmler
Inga
I
Probst
Ralf
R
Herwig
Mario
M
Drungowski
Karl Heinz
KH
Waldmann
D000189:Actinobacillus Infections / Q000235:genetics / Q000276:immunology / Q000473:pathology / Q000662:veterinary*; D016977:Actinobacillus pleuropneumoniae; D000818:Animals; D002874:Chromosome Mapping / Q000662:veterinary; D060467:Disease Resistance / Q000235:genetics* / Q000276:immunology; D005838:Genotype; D018895:Microsatellite Repeats / Q000235:genetics; D040641:Quantitative Trait Loci / Q000235:genetics*; D012044:Regression Analysis; D013552:Swine; D013553:Swine Diseases / Q000235:genetics / Q000276:immunology* / Q000382:microbiology* / Q000473:pathology