Parental modifiers, antisense transcripts and loss of imprinting.
The kinship theory of genomic imprinting has explained parent-specific gene expression as the outcome of an evolutionary conflict between the two alleles at a diploid locus of an offspring over how much to demand from parents. Previous models have predicted that maternally derived (madumnal) alleles will be silent at demand-enhancing loci, while paternally derived (padumnal) alleles will be silent at demand-suppressing loci, but these models have not considered the evolution of trans-acting modifiers that are expressed in parents and influence imprinted expression in offspring. We show that such modifiers will sometimes be selected to reactivate the silent padumnal allele at a demand-suppressing locus but will not be selected to reactivate the silent madumnal allele at a demand-enhancing locus. Therefore, imprinting of demand-suppressing loci is predicted to be less evolutionarily stable than imprinting of demand-enhancing loci.
D000483:Alleles; D000818:Animals; D005075:Biological Evolution; D019175:DNA Methylation; D016373:DNA, Antisense / Q000235:genetics; D005260:Female; D020868:Gene Silencing; D018392:Genomic Imprinting; D008297:Male; D008957:Models, Genetic; D009154:Mutation; D014158:Transcription, Genetic
D016373:DNA, Antisense