Copy number variation contributes to parallel local adaptation in an invasive plant

Area of Science:

• Evolutionary biology
• Genomics
• Population genetics

Background:

• Adaptation is key to species' evolution, but its genetic underpinnings are often unclear.
• Copy number variation (CNV) is a suspected driver of rapid adaptation, yet genome-wide studies are scarce due to logistical challenges.
• Previous research focused on candidate genes, limiting a comprehensive understanding of CNV's role in adaptation.

Purpose of the Study:

• To conduct a genome-wide analysis of CNV's contribution to adaptation.
• To investigate the role of CNVs in the adaptive evolution of the invasive weed Ambrosia artemisiifolia.
• To assess parallel adaptation signatures between native and invaded ranges.

Main Methods:

• Genome-wide analysis of CNVs in Ambrosia artemisiifolia.
• Utilized local principal component analysis (PCA) for CNV genotyping.
• Analyzed whole-genome sequences from samples spanning two centuries.

Main Results:

• Identified 16 large CNV regions, some exceeding 11 megabases.
• Observed parallel local adaptation signatures in CNVs between North American and European populations.
• Found eight CNV regions with rapid evolutionary change and significant frequency shifts over time.

Conclusions:

• CNVs provide compelling genome-wide evidence for rapid adaptation in natural populations.
• Demonstrated widespread reuse of CNVs in adaptation to similar selective pressures across different geographic ranges.
• Highlights the significant role of CNVs in contemporary evolutionary adaptation.