Journal of Applied Genetics 41(4), 2000, pp. 275-283
single gene multitrait effects in livestock by the use of Gibbs sampling
Anita DOBEK, Krzysztof MOLINSKI, Maciej SZYDLOWSKI, Tomasz SZWACZKOWSKI
Abstract: The paper presents a method of multivariate data analysis described by a model
which involves fixed effects, additive polygenic individual effects and the effects of a
major gene. To find the estimates of model parameters, the maximalisation of likelihood
function method is applied. The maximum of likelihood function is computed by the use of
the Gibbs sampling approach. In this approach, following the conditional posterior
distributions, values of all unknown parameters are generated. On the basis of the
obtained samples the marginal posterior densities as well as the estimates of fixed
effects, gene frequency, genotypic values, major gene, polygenic and error (co)variances
are calculated. A merical example, supplemented to theoretical considerations, deals
with data simulated according to the considered model.
Key words: EM algorithm, major gene, Gibbs sampling, pleiotropic effects.
Correspondence: A. DOBEK, Department of Mathematical and Statistical Methods, August
Cieszkowski Agricultural University, ul. Wojska Polskiego 28, 60637 Poznan, Poland.