Project description
Finding out if more is better when it comes to copies of the entire genome
Our cells multiply and divide continuously. Somatic (non-sex) cells undergo mitosis. The chromosomes are duplicated, the cell divides and one copy of the genome is passed to each of two daughter cells. This maintains the number of chromosomes (diploid number). Polyploidy, also called whole genome duplication (WGD), is not associated with cell division. It is widespread among eukaryotes and considered a major force in evolution and species diversification. However, a clear link between WGD and the increased complexity of organisms has been elusive, and it is not certain whether WGD is beneficial or detrimental on the whole. The EU-funded DOUBLE ADAPT project is studying whether WGD promotes adaptation in a variety of naturally polyploid plant species. Genomics studies in natural and manipulated populations could shed light on adaptive mechanisms relevant to survival in the face of climate change.
Objective
Whole genome duplication (WGD, polyploidization) is arguably the most massive genome-wide mutation whose ubiquity across eukaryotes suggests an adaptive benefit, though no mechanism has been identified. Consequently, a large controversy dominates the field whether WGD represents net benefit or detriment to evolutionary success.
I will test if WGD promotes adaptation in natural populations and address the underlying mechanism by estimating net fitness benefit of WGD vs. the role of post-WGD accumulation of adaptive variation. This question has not been satisfactorily addressed before because experimental studies of WGD were disconnected from field surveys and population genomics avoided complex polyploid genomes. Only recently, we have shown a proof-of-concept that WGD can increase the capacity of populations to accumulate adaptive variation in wild Arabidopsis. Yet the underlying mechanism still remains unknown.
I will address the adaptive consequences of WGD over a hierarchy of levels: genome, phenotype, population and species. In six naturally ploidy-variable plant species I plan to test if
(i) natural polyploid populations accumulate larger adaptive variation than diploids
(ii) WGD per se or post-WGD evolution brings important adaptive novelties
(iii) rates of positive selection increase after WGD
To achieve these goals, I will combine ecological genomics of natural populations with evolve-and-resequence experiments. To move beyond single-species correlative studies, I will manipulate the mutation itself via synthesis of neo-polyploid individuals and populations in six species. Then I will compare adaptation signals in genomes and phenotypes of synthetic polyploids and their natural diploid and tetraploid relatives.
This project will determine the adaptive value of WGD, an important force in evolution and crop domestication, with the ambition to improve our understanding of the role of large genomic mutations in natural selection and adaptation.
Fields of science
Programme(s)
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Funding Scheme
ERC-STG - Starting GrantHost institution
116 36 Praha 1
Czechia