Population history in Arabidopsis halleri using multilocus analysis

Area of Science:

• Population genetics
• Plant biology
• Bioinformatics

Background:

• Arabidopsis halleri is a pseudometallophyte with a fragmented distribution across Europe.
• Human activities are implicated in the dispersal of A. halleri populations.
• Understanding population history is crucial for assessing human impacts on genetic diversity.

Purpose of the Study:

• To investigate the population history of Arabidopsis halleri.
• To determine if human activities influenced its population genetic structure.
• To assess the implications for genetic diversity and adaptation.

Main Methods:

• Surveyed nucleotide variation at 24 loci in 12 individuals from a large A. halleri population.
• Conducted population genetic neutrality tests (Tajima's D, Wall's B).
• Utilized Approximate Bayesian Computation (ABC) and categorical regression analyses to model population structure.

Main Results:

• Nucleotide variation levels were within the expected range for the species.
• Neutrality tests initially rejected panmixia, suggesting non-neutral processes.
• ABC analysis favored a subdivision model over neutral, bottleneck, or population size change models.
• The subdivision model indicated admixture from two distinct source populations, likely mediated by human activity.

Conclusions:

• The population genetic structure of A. halleri is best explained by admixture from two source populations.
• Human-mediated mixing may restrict genetic diversity and adaptive potential.
• Findings necessitate consideration of non-neutral population variation in bioinformatic adaptation studies.