Nature: DNA mutations are not random "mutation preferences reflect natural selection in Arabidopsis"

By studying the genome of a small flowering weedy leafy vegetable, new insights into DNA mutations have been shed

The discovery could lead to advances in plant breeding and human genetics

The discovery, published in the journal Nature, fundamentally changes our understanding of evolution and could one day help researchers develop better crops and even help humans fight cancer

Mutations occur when DNA is damaged and not repaired, creating new variants

"We've always thought of genetic mutations as basically random," said Grey Monroe, an assistant professor in the UC Davis Department of Plant Sciences and lead author of the paper

The researchers spent three years sequencing the DNA of hundreds of Arabidopsis species

"It's a genetic model organism," Monroe said

Lab-grown plants come in many varieties

The work began at the Max Planck Institute, where researchers grow specimens in a protected laboratory environment, allowing defective plants that might not survive in nature to live in a Survive in a controlled space

Sequencing of these hundreds of Arabidopsis plants uncovered more than 1 million mutations

"At first glance, our findings appear to contradict the existing theory that initial mutations are completely random and that only natural selection determines which mutations are observed in an organism," said the Max Planck Institute.

What they found was not randomness, but genomic patches with low mutation rates

"These are the really important regions of the genome," Monroe said

These regions are also sensitive to the deleterious effects of new mutations

Plants evolved to protect themselves

Scientists have found that the way DNA wraps around different types of proteins is a good predictor of whether a gene will mutate

The discovery adds a surprising twist to Charles Darwin's theory of evolution by natural selection, as it reveals that plants evolved to protect their genes from mutation to ensure survival

"The plant has evolved a way to protect its most important places from mutation," Weigel said

future use

Knowing why certain regions of the genome are more prone to mutation than others could help breeders who rely on genetic variation to create better crops
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Scientists can also use this information to better predict or develop new treatments for diseases such as cancer caused by mutations
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"Our findings provide a more complete explanation of the forces driving natural patterns of variation; they should inspire new avenues of theoretical and practical research on the role of mutation in evolution," the paper concludes
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For more on this finding, see DNA mutations don't happen randomly
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Reference: "Mutational bias reflects natural selection in Arabidopsis" by J.
Grey Monroe, Thanvi Srikant, Pablo Carbonell-Bejerano, Claude Becker, Mariele Lensink, Moises ito-alonso, Marie Klein, Julia Hildebrandt, Manuela Neumann, Daniel Kliebenstein, Mao-Lun Weng, Eric Imbert, Jon ?gren, Matthew T.
Rutter, Charles B.
Fenster and Detlef Weigel, January 12, 2022, Nature
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DOI: 10.
1038/s41586-021-04269-6

Co-authors at UC Davis include Daniel Klebenstein, Mary Rensink and Mary Klein of the Department of Plant Sciences
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Researchers from Carnegie Institution for Science, Stanford University, Westfield State University, University of Montpellier, Uppsala University, College of Charleston and South Dakota State University participated in the study
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Funding came from the Max Planck Society, the National Science Foundation and the German Research Foundation
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