Sequence variation in LEAFY, a candidate gene for life history variation in Arabidopsis lyrata.

摘要

LEAFY (LFY) is a functional candidate for variation in resource allocation in Arabidopsis lyrata. We isolated and characterized LFY alleles from A. lyrata individuals from Spiterstulen Norway, Plech Germany, Ithaca N.Y., USA, and Mayodan N.C., USA. We found numerous coding polymorphisms, insertions, and deletions that were only in certain populations or locations with the majority of the variation in the European populations. Our data supports the idea that Central Europe has served as refugia for A. lyrata. We identified two possible miRNAs, one in all North American individuals and one in some European individuals. We also found a Little Athila retro-element in a European population. Our population genetics analyses found evidence that the majority of the polymorphisms in A. lyrata are deleterious and have not been eliminated by natural selection. Our research suggests that the power of genetic drift in small, out-crossing populations has a similar effect to inbreeding in larger populations. Deleterious mutations that would normally be eliminated by natural selection are kept at high frequencies and may reach fixation at a faster rate.