Natural GMOs Part 287. Plants evolve by structural changes to chromosomes. A modern summary

Highlights

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Plant genomes are dynamic, and gene-size insertions are prominent source of structural variation evident even within species.

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Gene insertions, tandem duplications, and gene fusions can be created by different genomic processes, including transposons, as well as recombination and DNA repair machinery.

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Tandemly duplicated genes themselves can serve as template for new structural variation.

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Extrachromosomal circular DNA is untapped source of gene amplification and variation that can propagate outside of main genome and have adaptive potential.

Summary

Plant genomes are shaped by structural variation. Gene-size insertions and among most prominent events and can have significant effects on amplification of gene families as well as facilitate new gene fusions. Transposable elements as well as plant DNA repair machinery have overlapping contributions to these events, and often work in synergy. Activity of transposable elements is often lineage specific and can preferentially affect specific gene families, such as disease resistance genes. Once duplicated, genes themselves can serve templates for additional variation that can arise from non-allelic homologous recombination. Non-homologous DNA repair mechanisms contribute to additional variation and diversify the mechanisms of gene movement, such as through ligation of extra-chromosomal DNA fragments. Genomic processes that generate structural variation can be induced by stress and, therefore, can provide adaptive potential. This review describes mechanisms that contribute to gene-size structural variation in plants, result in gene duplication and generation of new plant genes through gene fusion.

The role of transposable elements and DNA damage repair mechanisms in gene duplications and gene fusions in plant genomes (Open Access)

Ksenia V Krasileva

Current Opinion in Plant Biology 2019, 48:18–25

This review comes from a themed issue on Genome studies and molecular genetics

Edited by Steven Kelly

For a complete overview see the Issue and the Editorial

Available online 5th March 2019

https://doi.org/10.1016/j.pbi.2019.01.004

1369-5266/© 2019 The Author. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).