Issue |
Genet. Sel. Evol.
Volume 34, Number 6, November-December 2002
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Page(s) | 657 - 678 | |
DOI | https://doi.org/10.1051/gse:2002030 |
DOI: 10.1051/gse:2002030
The covariance between relatives conditional on genetic markers
Yuefu Liua, Gerald B. Jansena and Ching Y. Lina, ba Department of Animal and Poultry Science, University of Guelph, Guelph, ON N1G 2W1, Canada
b Dairy and Swine Research and Development Centre, Agriculture and Agri-Food, Canada
(Received 13 August 2001; accepted 3 June 2002)
Abstract
The development of molecular genotyping techniques makes it possible
to analyze quantitative traits on the basis of individual loci. With
marker information, the classical theory of estimating the genetic
covariance between relatives can be reformulated to improve the
accuracy of estimation. In this study, an algorithm was derived for
computing the conditional covariance between relatives given genetic
markers. Procedures for calculating the conditional relationship
coefficients for additive, dominance, additive by additive, additive
by dominance, dominance by additive and dominance by dominance effects
were developed. The relationship coefficients were computed based on
conditional QTL allelic transmission probabilities, which were
inferred from the marker allelic transmission probabilities. An
example data set with pedigree and linked markers was used to
demonstrate the methods developed. Although this study dealt with two
QTLs coupled with linked markers, the same principle can be readily
extended to the situation of multiple QTL. The treatment of missing marker
information and unknown linkage phase between markers for calculating
the covariance between relatives was discussed.
Key words: covariance between relatives / molecular marker / QTL / transmission probability / relationship matrix
Correspondence and reprints: Yuefu Liu
e-mail: yuefuliu@uoguelph.ca
© INRA, EDP Sciences 2002