Objective
Whole genome duplication (WGD) is a drastic event that results in the creation of new genetic material and has been suggested to play a major role in evolutionary innovations and adaptation. While ancestral WGDs (paleoploidizations) are common in plants, only a handful examples have been proposed in animals, such as in vertebrates or salmons. Among invertebrates, WGD events have been inferred in chelicerates, an arthropod clade including marine and terrestrial groups the arachnids. Specifically, a shared event in the common ancestor of spider and scorpions, and up to 3 independent rounds in the marine horseshoe crabs. However, many of these inferences are mostly based on evidence from few loci, such as Hox genes, with a recent study questioning the validity of these conclusions. Therefore, genome-wide investigations with a diverse taxon sampling may help to answer how many paleoploidization events have taken place in chelicerates.
The CheliPloidy project will investigate the signals of WGD in chelicerates using newly assembled complete genome encompassing most of their diversity. Importantly, no study has considered that return to diploidy may have happened at different intervals (delayed rediploidization), scenario compatible with the different gene histories seen in the group. We will employ multiple state-of-the-art methods and develop novel ones to look for these signals. For example, we will analyse thousands of gene families trees, assess their synteny, and compare signals of divergence among within-species paralogs (including ohnologs derived from the WGD). As the phylogeny of chelicerates is contentious, we will test the most likely scenarios alternative backbone trees to polarize patterns of WGD (how many and which are shared). Altogheter, this project will not only sheds light on the complex genome evolution and the phylogeny of chelicerates, but also demonstrates how a combination of comparative methods can be used to infer signals of ancient WGDs.
Keywords
Programme(s)
- HORIZON.1.2 - Marie Skłodowska-Curie Actions (MSCA) Main Programme
Funding Scheme
HORIZON-TMA-MSCA-PF-EF - HORIZON TMA MSCA Postdoctoral Fellowships - European FellowshipsCoordinator
08007 Barcelona
Spain