TABLE 2.
Summary of the relevant QTL studies pointing toward the implication of innate or intrinsic mechanisms in disease resistance.
| Fish species | Disease | Challenge type | Experimental design (genotyped fish in the analysis) | Genetic molecular markers | Resistance traits | Number of detected QTL | Size of detected QTL | % variance explained by QTL | Publication |
| Atlantic salmon (S. salar) | AGD | Immersion | 1333 fish (136 FS) | 53,109 SNPs | Lesion score | 3 QTL + smaller QTL | 6 kb–1.2 Mb | 4.6–5.3% of Vg | Boison et al., 2019b |
| Rainbow trout (O. mykiss) | BCWD | Immersion, injection (im) | DH fish 195 for immersion, 115 for injection | 2130 SNPs | BS, TTD, COX endurance | 15 QTL | 20–80 cM | 7–18% of Vp | Fraslin et al., 2018 |
| Atlantic salmon (S. salar) | IPN | Natural outbreak | 584 fish (10 FS) | Less than 100 microsatellites | BS | 4 QTL | 10–69 cM | 8.9–24.6% of Vp | Houston et al., 2008 |
| Atlantic salmon (S. salar) | IPN | Immersion | 1321 fish (10 FS) | 7 microsatellites | BS and TTD | 3 QTL | 10 cM | 50.9% of Vp for Ssa26 | Houston et al., 2010 |
| Atlantic salmon (S. salar) | IPN | Immersion | 28 fish (2 FS) and 9,000 fish (400 FS) | 6712 SNPs | BS | 1 QTL | 2 cM | Houston et al., 2012 | |
| Atlantic salmon (S. salar) | IPN | Immersion | 634 fry (20 FS) over 2 mph | 8 microsatellites | BS | 1 major QTL on Ssa26 | 7 cM | 0–43.9% of Vp | Gheyas et al., 2010 |
| Atlantic salmon (S. salar) | IPN | Cohabitation | 1896 fish (10 FS) at 10 mph | 136 microsatellites | BS | 3 QTL with 1 major QTL | 4 cM | 29% of Vp 83% of Vg | Moen et al., 2009 |
| Atlantic salmon (S. salar) | IPN | Immersion | 4140 fish (207 FS) | 3 microsatellites | BS | 1 major QTL on Ssa26 | Moen et al., 2015 | ||
| Turbot (S. maximus) | Scuticociliatosis | Cohabitation | 1394 fish (36 FS) | 18,125 SNPs | Resistance Endurance Resilience | 4 QTL: 1 major and 3 minors | Up to 9.3 Mb | Up to 33% Vg | Saura et al., 2019 |
| Turbot (S. maximus) | VHS | Injection (ic) | 280 fish (3 FS) | 93 microsatellites | BS and TTD | 7 QTL | 4–30 cM | 3–14% Vp | Rodríguez-Ramilo et al., 2014 |
| Rainbow trout (O. mykiss) | VHS | Immersion | 1325 DH fish + 450 DH fish (VREFT) | 131–142 microsatellites | VREFT and COX | 7 QTL (1 major) | 1 cM | Up to 65% of Vp | Verrier et al., 2013a |
AGD, amoebic gill disease; BCWD, bacterial cold water disease; IPN, infectious pancreatic necrosis; VHS, viral hemorrhagic septicemia; BS, binary survival that takes into account the outcomes of the challenge as dead or alive; TTD, time to death, measured as the time (in days or hours) between the infection and the day of death of a fish; COX, survival analysis with a Cox model (Cox, 1972); VREFT, viral replication in excised tissue; mph, month post hatching; Vp, phenotypic variance of the resistance trait; Vg, genetic or genomic variance of the resistance trait; FS, full-sib families; DH, doubled homozygous fish; BC, back-cross; SNP, single-nucleotide polymorphism; QTL, quantitative trait loci; cM, centi-Morgan; im, intramuscular; ic, intracelomical. Size of detected QTL correspond to either confidence intervals when calculated or cumulated windows with significant SNPs.