EurekaMag.com logo
+ Site Statistics
References:
53,214,146
Abstracts:
29,074,682
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Estimation of effects of quantitative trait loci in large complex pedigrees






Genetics 146(1): 409-416

Estimation of effects of quantitative trait loci in large complex pedigrees

A method was derived to estimate effects of quantitative trait loci (QTL) using incomplete genotype information in large outbreeding populations with complex pedigrees. The method accounts for background genes by estimating polygenic effects. The basic equations used are very similar to the usual linear mixed model equations for polygenic models, and segregation analysis was used to estimate the probabilities of the QTL genotypes for each animal. Method R was used to estimate the polygenic heritability simultaneously with the QTL effects. Also, initial allele frequencies were estimated. The method was tested in a simulated data set of 10,000 animals evenly distributed over 10 generations, where 0, 400 or 10,000 animals were genotyped for a candidate gene. In the absence of selection, the bias of the QTL estimates was < 2%. Selection biased the estimate of the Aa genotype slightly, when zero animals were genotyped. Estimates of the polygenic heritability were 0.251 and 0.257, in absence and presence of selection, respectively, while the simulated value was 0.25. Although not tested in this study, marker information could be accommodated by adjusting the transmission probabilities of the genotypes from parent to offspring according to the marker information. This renders a QTL mapping study in large multi-generation pedigrees possible.

(PDF 0-2 workdays service: $29.90)

Accession: 002831669

PMID: 9136029



Related references

Interval mapping of quantitative trait loci in complex pedigrees. Korean Journal of Genetics 23(4): 349-357, December, 2001

Mapping quantitative trait loci with various types of progeny from complex pedigrees. Asian Australasian Journal of Animal Sciences 14(11): 1505-1510, 2001

Homozygosity mapping of quantitative trait loci in complex inbred pedigrees. American Journal of Human Genetics 67(4 Supplement 2): 327, October, 2000

QTL Express: Mapping quantitative trait loci in simple and complex pedigrees. Bioinformatics (Oxford) 18(2): 339-340, February, 2002

Mapping quantitative trait loci in complex pedigrees: a two-step variance component approach. Genetics 156(4): 2081-2092, 2000

Modulation of multiple experimental arthritis models by collagen-induced arthritis quantitative trait loci isolated in congenic rat lines: different effects of non-major histocompatibility complex quantitative trait loci in males and females. Arthritis and Rheumatism 46(8): 2225-2234, 2002

Simultaneous mining of linkage and linkage disequilibrium to fine map quantitative trait loci in outbred half-sib pedigrees: revisiting the location of a quantitative trait locus with major effect on milk production on bovine chromosome 14. Genetics 161(1): 275-287, 2002

Quantitative trait locus analysis of longitudinal quantitative trait data in complex pedigrees. Genetics 171(3): 1365-1376, 2005

Analysis of quantitative trait loci using hybrid pedigrees: quantitative traits of animals. Genetika 43(2): 265-275, 2007

Proceedings of the 6th World Congress on Genetics Applied to Livestock Production, Armidale, Australia, January 11-16, 1998. Volume 26: Quantitative genetic theory; selection theory and experiments; internationalisation of breeding programs; detection of quantitative trait loci; exploitation of quantitative trait loci; quantitative trait loci maps; transgenics; developmental genetics. Proceedings of the 6th World Congress on Genetics Applied to Livestock Production, Armidale, Australia, January 11-16, 1998 Volume 26: Quantitative genetic theory; selection theory and experiments; internationalisation of breeding programs; detection of quantitative trait loci; exploitation of quantitative trait loci; quantitative trait loci maps; transgenics; developmental genetics: xvi + 656 pp., 1998