Genetic variance components when fluctuating imprinting patterns are present

Abstract Text: Genomic imprinting may be unstable over time (developmentally regulated imprinting) or between tissues (tissue specific imprinting). How this phenomena affect genetic covariance was investigated both in theory and by simulation. Thereby the first aim was to theoretically derive the total imprinting variance, which has contributions from all imprinted loci with different kinds of stable (paternal, maternal) or fluctuating (changing from either paternal or maternal to unimprinted) expression patterns. Second, the total imprinting variance was estimated in simulated data by employing a recently proposed model with two additive genetic effects per individual. REML-estimates of variance components were in excellent agreement with simulated parameters. Therefrom validity of the underlying theory can be concluded as well as the broad generality of the applied imprinting BLUP-model.

Keywords:

genomic imprinting

epigenetics

variance components