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Genetic heterogeneity of within-family variance of body weight in Atlantic salmon (Salmo salar).
- Source :
- Genetics Selection Evolution; Oct2013, Vol. 45 Issue October, p1-8, 8p
- Publication Year :
- 2013
-
Abstract
- Background: Canalization is defined as the stability of a genotype against minor variations in both environment and genetics. Genetic variation in degree of canalization causes heterogeneity of within-family variance. The aims of this study are twofold: (1) quantify genetic heterogeneity of (within-family) residual variance in Atlantic salmon and (2) test whether the observed heterogeneity of (within-family) residual variance can be explained by simple scaling effects. Results: Analysis of body weight in Atlantic salmon using a double hierarchical generalized linear model (DHGLM) revealed substantial heterogeneity of within-family variance. The 95% prediction interval for within-family variance ranged from ~0.4 to 1.2 kg<superscript>2</superscript>, implying that the within-family variance of the most extreme high families is expected to be approximately three times larger than the extreme low families. For cross-sectional data, DHGLM with an animal mean sub-model resulted in severe bias, while a corresponding sire-dam model was appropriate. Heterogeneity of variance was not sensitive to Box-Cox transformations of phenotypes, which implies that heterogeneity of variance exists beyond what would be expected from simple scaling effects. Conclusions: Substantial heterogeneity of within-family variance was found for body weight in Atlantic salmon. A tendency towards higher variance with higher means (scaling effects) was observed, but heterogeneity of within-family variance existed beyond what could be explained by simple scaling effects. For cross-sectional data, using the animal mean sub-model in the DHGLM resulted in biased estimates of variance components, which differed substantially both from a standard linear mean animal model and a sire-dam DHGLM model. Although genetic differences in canalization were observed, selection for increased canalization is difficult, because there is limited individual information for the variance sub-model, especially when based on cross-sectional data. Furthermore, potential macro-environmental changes (diet, climatic region, etc.) may make genetic heterogeneity of variance a less stable trait over time and space. [ABSTRACT FROM AUTHOR]
- Subjects :
- HETEROGENEITY
ATLANTIC salmon
BODY weight
FISH weight
CROSS-sectional method
Subjects
Details
- Language :
- English
- ISSN :
- 0999193X
- Volume :
- 45
- Issue :
- October
- Database :
- Complementary Index
- Journal :
- Genetics Selection Evolution
- Publication Type :
- Academic Journal
- Accession number :
- 93400554
- Full Text :
- https://doi.org/10.1186/1297-9686-45-41