Interspecific introgression mediates adaptation to whole genome duplication

Area of Science:

• Evolutionary Biology
• Population Genetics
• Genomics

Background:

• Adaptive gene flow is crucial for evolution across all life forms.
• Previous research has not demonstrated bidirectional gene flow's role in adapting core genetic processes.
• Concerted molecular changes in meiotic machinery were observed in *Arabidopsis arenosa* after whole-genome duplication (WGD).

Purpose of the Study:

• To investigate if adaptive gene flow between *Arabidopsis arenosa* and *Arabidopsis lyrata* mediated adaptation to WGD.
• To test the hypothesis of reciprocal gene flow facilitating adaptation to WGD.

Main Methods:

• Population genomic analysis.
• Comparative WGD timing assessment between *A. arenosa* and *A. lyrata*.
• Identification of gene flow patterns at functionally interacting loci.

Main Results:

• Whole-genome duplication (WGD) occurred more recently in *A. lyrata* than in *A. arenosa*.
• Evidence of gene flow from *A. arenosa* to *A. lyrata*, potentially rescuing nascent WGD events.
• Detection of gene flow in the opposite direction (*A. lyrata* to *A. arenosa*) at loci under strong selection.

Conclusions:

• Bidirectional gene flow played a critical role in species survival following WGD.
• The interaction and gene exchange between these species led to synergistic evolutionary outcomes.
• Adaptive gene flow is a key mechanism for adapting core biological processes to WGD.