In its 234 years, an oak tree in Switzerland has only had a few mutations accumulate in its genome, Nature News reports. This suggests that the oak and other plants may have a means of protecting themselves from mutations.
"If you just accumulate more and more mutations, you would eventually die of mutational meltdown," Cris Kuhlemeier from the University of Bern tells Nature News.
The tree, known as the Napoleon oak, is located on the University of Lausanne campus, and it was already 22 years old when Napoleon Bonaparte's troops passed by it on their way to Italy.
Researchers from Lausanne gathered 26 leaf samples from different parts of the tree for sequencing and analysis. According to Nature News, many scientists suspected that the older branches and the newer branches would differ as the tree's stem cells accumulated mutations over time.
But as they report in an article posted to BioRxiv, the Lausanne researchers found that the tree contained few fixed somatic SNVs. Sixteen of the 17 SNVs they did find appeared to be neutral changes. This, they say, "indicate[s] that the stem cells of shoot meristems in trees are robustly protected from accumulation of mutations, analogous to the germline in animals."