Siberian Arabidopsis lyrata

A. lyrata is a member of the genus Arabidopsis with wide geographical distribution comparable to the model A. thaliana, however, shifted towards boreal regions. We explore the natural variation of ploidy in A. lyrata and the mechanisms of the establishment of new polyploid populations in the face of environmental challenges. The difficulty in establishing polyploids is adapting meiotic regulation to provide the faithful chromosome segregation after the whole-genome duplication, often in conditions of reduced effective population sizes, harsh environments, and competition with more common diploids. In contrast to the European tetraploid A. lyrata populations which establishment was facilitated by the introgression of already adapted to tetraploidy A. arenosa alleles, the formation of the Siberian tetraploid A. lyrata is independent. This provides a rare opportunity to study parallel adaptation to whole-genome duplication in closely related populations and cross-species comparisons.

In a coordinated effort with the group of Levy Yant, we sequence the entire herbarium collection (~120 different geo-locations across Eurasia) of A. lyrata at Moscow State University. This will allow us to estimate the natural ploidy variation in A. lyrata species, describe population structure, evolution and climate adaptation of the species, as well as provide a powerful comparative dataset to the 1001 A. thaliana genomes project. Additionally, we obtained fresh A. lyrata seeds from 20 populations of varying ploidy in Yakutia (collected by Nikita Tikhomirov), which are now growing in the greenhouse at MPIPZ. This part of the project is focused on the mechanisms of the early establishment of the stable tetraploid lineages.