Epigenetic information – Unexplored source of natural variation

Abstract

Rapid progress is being made at the population-level in orchids, with a series of new molecular techniques being applied. One of the major problems observed in several groups of temperate orchids has been that ecologically distinct “taxa” do not appear to be genetically distinct. For example, we know that Dactylorhiza traunsteineri, D. majalis, and D. ebudensis are the products of hybridization between D. fuchsii and D. incarnata, but they have different ecologies and distributions within northwestern Europe. By comparing fingerprinting analyses of expressed regions to fingerprinting studies of methylation-sensitive sites in genomic DNA, we can detect patterns that indicate that some of these differences are due to changing epigenetic effects, which have been shown in several groups to be subject to environmental influence. Thus, taxa that are ecologically distinct but still appear genetically uniform may be the result of altered epigenetic controls of gene expression without any change in the underlying genetic material.