TY - JOUR

T1 - Whole-genome association study searching for QTL for Aeromonas salmonicida resistance in rainbow trout

AU - Marana, Moonika H.

AU - Karami, Asma M.

AU - Ødegård, Jørgen

AU - Zuo, Shaozhi

AU - Jaafar, Rzgar M.

AU - Mathiessen, Heidi

AU - von Gersdorff Jørgensen, Louise

AU - Kania, Per W.

AU - Dalsgaard, Inger

AU - Nielsen, Torben

AU - Buchmann, Kurt

N1 - Publisher Copyright: © 2021, The Author(s).

PY - 2021

Y1 - 2021

N2 - Aeromonas salmonicida subsp. salmonicida, the causative agent of furunculosis, has extensive negative effects on wild and farmed salmonids worldwide. Vaccination induces some protection under certain conditions but disease outbreaks occur even in vaccinated fish. Therefore, alternative disease control approaches are required to ensure the sustainable expansion of rainbow trout aquaculture. Selective breeding can be applied to enhance host resistance to pathogens. The present work used genome-wide association study (GWAS) to identify quantitative trait loci (QTL) associated with A. salmonicida resistance in rainbow trout. A total 798 rainbow trout exposed to A. salmonicida by bath challenge revealed 614 susceptible and 138 resistant fish. Genotyping was conducted using the 57 K single nucleotide polymorphism (SNP) array and the GWAS was performed for survival and time to death phenotypes. We identified a QTL on chromosome 16 and located positional candidate genes in the proximity of the most significant SNPs. In addition, samples from exposed fish were examined for expression of 24 immune-relevant genes indicating a systematic immune response to the infection. The present work demonstrated that resistance to A. salmonicida is moderately heritable with oligogenic architecture. These result will be useful for the future breeding programs for improving the natural resistance of rainbow trout against furunculosis.

AB - Aeromonas salmonicida subsp. salmonicida, the causative agent of furunculosis, has extensive negative effects on wild and farmed salmonids worldwide. Vaccination induces some protection under certain conditions but disease outbreaks occur even in vaccinated fish. Therefore, alternative disease control approaches are required to ensure the sustainable expansion of rainbow trout aquaculture. Selective breeding can be applied to enhance host resistance to pathogens. The present work used genome-wide association study (GWAS) to identify quantitative trait loci (QTL) associated with A. salmonicida resistance in rainbow trout. A total 798 rainbow trout exposed to A. salmonicida by bath challenge revealed 614 susceptible and 138 resistant fish. Genotyping was conducted using the 57 K single nucleotide polymorphism (SNP) array and the GWAS was performed for survival and time to death phenotypes. We identified a QTL on chromosome 16 and located positional candidate genes in the proximity of the most significant SNPs. In addition, samples from exposed fish were examined for expression of 24 immune-relevant genes indicating a systematic immune response to the infection. The present work demonstrated that resistance to A. salmonicida is moderately heritable with oligogenic architecture. These result will be useful for the future breeding programs for improving the natural resistance of rainbow trout against furunculosis.

U2 - 10.1038/s41598-021-97437-7

DO - 10.1038/s41598-021-97437-7

M3 - Journal article

C2 - 34497310

AN - SCOPUS:85114633405

VL - 11

JO - Scientific Reports

JF - Scientific Reports

SN - 2045-2322

M1 - 17857

ER -