Bayesian multi-QTL mapping for growth curve parameters

BMC Proceedings

Proceedings

Henri C M Heuven¹  Luc L G Janss² 

[1] Clinical Sciences of Companion Animals Faculty of Veterinary Medicine, Utrecht University, P.O. box 80163, 3508 TD, Utrecht, The Netherlands;Animal Breeding and Genomics Centre, Wageningen University, P.O. box 338, 6700AH, Wageningen, the Netherlands;Department of Genetics and Biotechnology, Aarhus University DJF, P.O. Box 50, 8830, Tjele, Denmark;

关键词: Latent Variable;    Genetic Correlation;    Bayesian Algorithm;    Single SNPs;    Bayesian Variable Selection;   

DOI  :  10.1186/1753-6561-4-S1-S12

来源: Springer

【 摘 要 】

BackgroundIdentification of QTL affecting a phenotype which is measured multiple times on the same experimental unit is not a trivial task because the repeated measures are not independent and in most cases show a trend in time. A complicating factor is that in most cases the mean increases non-linear with time as well as the variance. A two- step approach was used to analyze a simulated data set containing 1000 individuals with 5 measurements each. First the measurements were summarized in latent variables and subsequently a genome wide analysis was performed of these latent variables to identify segregating QTL using a Bayesian algorithm.ResultsFor each individual a logistic growth curve was fitted and three latent variables: asymptote (ASYM), inflection point (XMID) and scaling factor (SCAL) were estimated per individual. Applying an 'animal' model showed heritabilities of approximately 48% for ASYM and SCAL while the heritability for XMID was approximately 24%. The genome wide scan revealed four QTLs affecting ASYM, one QTL affecting XMID and four QTLs affecting SCAL. The size of the QTL differed. QTL with a larger effect could be more precisely located compared to QTL with small effect. The locations of the QTLs for separate parameters were very close in some cases and probably caused the genetic correlation observed between ASYM and XMID and SCAL respectively. None of the QTL appeared on chromosome five.ConclusionsRepeated observations on individuals were affected by at least nine QTLs. For most QTL a precise location could be determined. The QTL for the inflection point (XMID) was difficult to pinpoint and might actually exist of two closely linked QTL on chromosome one.

【 授权许可】

Unknown   
© Heuven and Janss; licensee BioMed Central Ltd. 2010. This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.