Quantitative trait loci for resistance to Flavobacterium psychrophilum in rainbow trout: effect of the mode of infection and evidence of epistatic interactions

Table 2 Results of QTL analyses for resistance traits after an immersion challenge with F. psychrophilum

Trait	QTL	LRTmax	Position (cM)	CI (95%)	QTL effect	Resistance origin	Survival rate (%) according to allele origin at the QTL		% phenotypic variance explained in DH progeny
Trait	QTL	LRTmax	Position (cM)	CI (95%)	QTL effect	Resistance origin	AP2	B57	% phenotypic variance explained in DH progeny
RESISTANCE	Omy2	14.04*	14	3–32	3.73	B57	69	89	–
	Omy3	39.87***	88	82–93	0.09	AP2	94	53	–
	Omy21	12.65*	99	64–103	3.08	B57	66	87	–
STATUS	Omy2	13.17*	14	2–36	− 0.19	B57	69	89	6%
	Omy3	39.47***	88	81–93	+ 0.33	AP2	94	53	18%
	Omy21	12.36*	99	63–104	− 0.18	B57	66	87	7%
ENDURANCE	Omy20	12.54*	28	5–37	+ 4.93	B57	–	–	nc
ENDURANCE	Omy27	13.56*	26	10–47	+ 5.65	B57	–	–	nc

RESISTANCE: overall resistance, analysed with a Cox model survival analysis that takes failure time to death and final survival (censored observations) into account; STATUS: (dead/surviving) phenotype at the end of the challenge, analysed as a binary trait; ENDURANCE: time to death in days after infection for dead fish only, analysed as a Gaussian trait; LRTmax = maximum of likelihood ratio test; Position in the genetic map in centimorgans (cM); CI = confidence interval; Chromosome-wide significant at *P ≤ 0.01; Genome-wide significant at ***P ≤ 0.01; The QTL effect was measured as the relative risk for RESISTANCE (B57 as the reference, risk = 1), as half the difference between the mean values of the two classes of homozygous progeny (individual values fixed as 1 for survivors and 0 for dead fish) for STATUS and as half the difference (in days) between the mean date of death of the two classes of homozygous progeny for ENDURANCE

ISSN: 1297-9686