Identification of two QTL influencing upper temperature tolerance in three rainbow trout (Oncorhynchus mykiss) half-sib families

Abstract

We searched for linkage among 24 polymorphic loci (allozymes, RAPD, microsatellites) in three half-sib backcross families of rainbow trout (Oncorhynchus mykiss) produced by crossing strains divergent for the quantitative trait of upper temperature tolerance. Seven significant and two suggestive pairwise linkage associations between molecular marker loci were observed involving 14 loci clustered into four linkage groups. The association between a pair of allozyme loci (sIDHP-3* and mMEP-2*) has been reported previously. Recombination rates varied greatly between the sexes and families. Two quantitative trait loci (QTL) were mapped by detecting a significant association between variance in upper temperature tolerance and alleles at the microsatellite loci Omy325UoG and Ssa14DU. The two QTL appear to reside in different linkage groups and account for :13 per cent and 9 per cent of the overall additive genetic variance in upper temperature tolerance. No significant interaction was detected between Omy325UoG and Ssa14DU suggesting that the effects of the QTL are additive.

Genome-scan analysis for quantitative trait loci in an F2 tilapia hybrid

“…In our study, 1-4 QTLs were detected for each of the stress-response traits. The extents of variance explained by the stress response QTLs were similar to those observed for QTLs for temperature tolerance in trout, ranging from 9% to 13% (Jackson et al 1998). In a trout genome-scan, O'Malley et al (2003) detected QTLs for body weight in seven different linkage groups, while in this study QTLs for body weight were detected in six linkage groups.…”

“…Some of the QTLs are for disease resistance (Palti et al 1999a;Ozaki et al 2001;Grimholt et al 2003) and tolerance of thermal stress (Jackson et al 1998;Perry et al 2001;Cnaani et al 2003a). In all of these studies the measured parameter was fish survival, which is the tertiary response to stress (Barton 2002).…”

“…Seven other markers (GM47, GM131 , GM552 , UNH208 , UNH881 , UNH952 , UNH998) were associated with more than one trait, reducing to some extent the possibility of association resulting from type I statistical error. Jackson et al (1998) searched among 24 polymorphic loci for linkage with temperature tolerance in trout, and detected two QTLs. In our study, 1-4 QTLs were detected for each of the stress-response traits.…”

Characterization of Na, K-ATPase genes in Atlantic salmon (Salmo salar) and comparative genomic organization with rainbow trout (Oncorhynchus mykiss)

“…Genetic markers for Na, K-ATPase a and b subunit genes were mapped using reference meiotic panels described elsewhere as Br5 and Br6 in Atlantic salmon (Woram et al 2003) and lot 25 in rainbow trout (Jackson et al 1998). Segregation data were collected from 46 to 48 progeny in each family and analysed against other markers in the linkage maps currently assembled in our laboratory as part of international collaborative efforts (Sakamoto et al 2000;Woram et al 2003;Danzmann et al unpublished results).…”

Quantitative trait loci (QTLs) associated with resistance/susceptibility to infectious pancreatic necrosis virus (IPNV) in rainbow trout (Oncorhynchus mykiss)

“…They reported sexspeci®c SSR linkage map dierences in recombination rates and tetrasomic inheritance. These linkage maps have facilitated the analysis of quantitative trait loci (QTLs) that control complex traits, such as upper temperature tolerance (Jackson et al 1998) and spawning time (Sakamoto et al 1999). Demand for QTL analyses of complex traits is increasing because of its potential to facilitate the manipulation of important traits in ®sh breeding.…”