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ARS Home » Northeast Area » Leetown, West Virginia » Cool and Cold Water Aquaculture Research » Research » Publications at this Location » Publication #243509
Title: Evidence of major genes affecting stress response in rainbow trout using Bayesian methods of complex segregation analysis

Author
item Vallejo, Roger
item Rexroad, Caird
item Silverstein, Jeffrey
item JANSS, LUC L. - STATE UNIVERSITY OF DENMARK
item Weber, Gregory - Greg

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/2/2009
Publication Date: 7/31/2009
Citation: Vallejo, R.L., Rexroad III, C.E., Silverstein, J., Janss, L.G., Weber, G.M. 2009. Evidence of major genes affecting stress response in rainbow trout using Bayesian methods of complex segregation analysis. Journal of Animal Science. 87:3490-3505.

Interpretive Summary: As a first step towards the genetic mapping of quantitative trait loci (QTL) affecting stress response variation in rainbow trout, we performed complex segregation analyses (CSA) fitting mixed inheritance models of plasma cortisol using Bayesian methods in large full-sib families of rainbow trout. To date, no studies have been conducted to determine the mode of inheritance of stress response as measured by plasma cortisol response using a crowding stress paradigm and CSA in rainbow trout. The main objective of this study was to determine the mode of inheritance of plasma cortisol following a crowding stress. The results from fitting mixed inheritance models with Bayesian CSA, suggest that one or more major genes with dominant cortisol-decreasing allele and small additive genetic effects of a large number of independent genes likely underlie the genetic variation of plasma cortisol in the evaluated rainbow trout families. Plasma cortisol is highly genetically determined with heritability of 0.22 to 0.39. Furthermore, a major gene with an additive effect of -42 ng/ml is segregating in this rainbow trout population. These findings provide a basis for designing and executing genome scans to identify QTL for stress response in rainbow trout broodstock and markers for selective breeding.

Technical Abstract: As a first step towards the genetic mapping of quantitative trait loci (QTL) affecting stress response variation in rainbow trout, we performed complex segregation analyses (CSA) fitting mixed inheritance models of plasma cortisol using Bayesian methods in large full-sib families of rainbow trout. To date, no studies have been conducted to determine the mode of inheritance of stress response as measured by plasma cortisol response using a crowding stress paradigm and CSA in rainbow trout. The main objective of this study was to determine the mode of inheritance of plasma cortisol following a crowding stress. The results from fitting mixed inheritance models with Bayesian CSA, suggest that one or more major genes with dominant cortisol-decreasing allele and small additive genetic effects of a large number of independent genes likely underlie the genetic variation of plasma cortisol in the evaluated rainbow trout families. Plasma cortisol is highly genetically determined with heritability of 0.22 to 0.39. Furthermore, a major gene with an additive effect of -42 ng/ml (~1.0 genetic standard deviation) is segregating in this rainbow trout broodstock population. These findings provide a basis for designing and executing genome-wide linkage studies to identify QTL for stress response in rainbow trout broodstock and markers for selective breeding.