Dr Levi Yant on the pervasive population genomic impacts of genome duplication, gene flow, and selection

On 24 May, Dr Levi Yant from John Innes Centre gave an intriguing talk on the causes and consequences of various genomic events, and their implications for plant adaptation to novel habitats. Using diploid and tetraploid Arabidopsis arenosa and Arabodopsis lyrata, Dr. Yant’s group aims to understand whether the adaptive genes in novel populations originate from novel mutations, standing variation, or gene flow from other populations/ species.

Investigating A. arenosa populations that are adapted to serpentine soil (an extremely harsh environment for plants due to lack of nutrients and abundance of heavy metals), they discovered that there was gene flow from serpentine soil-adapted populations from its close relative, A. lyrata, allowing A. arenosa populations to adapt quickly to the harsh environment.

Dr. Yant’s group discovered that many generations after whole genome duplication, the number of crossovers during meiosis decreased, allowing unimpaired gamete production. Comparing diploid and tetraploid genomes of A. arenosa, they found important genes in tetraploids that are involved in chromosome pairing and crossover designation, allowing tetraploids to overcome crossover problems during cell division.

Some researchers argued that genome duplication is an evolutionary dead-end, while others argued the opposite. Sequencing hundreds of genomes from these two species, both diploid and tetraploid and from tens of populations around their range, Dr. Yant hopes to elucidate the consequences of genome duplication by studying the dynamics of gene flow and selection in this large-scale project. This would undoubtedly help us understand how organisms acquire and utilise novel genes to overcome survival obstacles or conquer novel habitats. 

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Edgar Wong is a DPhil student in the field of evolutionary genetics and plant speciation.

 

 

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