DNA evolves at different rates, depending on chromosome structure
The structure of how DNA is stored in archaea makes a significant difference to how quickly it evolves, according to a new study from researchers at Indiana University.
The study, led by molecular biologist Stephen Bell, Distinguished Professor and Chair of the College of Arts and Sciences’ Department of Molecular and Cellular Biochemistry at Indiana University (IU) Bloomington, was recently published in Nature Microbiology† The findings could influence research into treating genetic diseases such as cancer.
“The most exciting thing we’ve revealed is the idea that the shape of a DNA molecule can influence its ability to change,” Bell said. “In the early 20th century, modernist architecture had the idea that the shape of a building should follow its function. But what we see in these organisms is that shape actually influences evolution over time. How DNA is structured, it can change, creating an evolutionary feedback loop.”
Archaea, single-celled microorganisms discovered in the 1970s, are one of three domains of life on Earth that scientists use to classify all life forms. The other two domains are bacteria and eukaryotes, including mammals and humans. Archaea is possibly the oldest domain of the three.
“You can think of archaea as molecular fossils,” Bell said. “Studying them is like stepping into a time machine and looking back about 2 billion years.”
Previous research by Bell and his IU collaborators, Rachel Samson, an assistant researcher in the Department of Molecular and Cellular Biochemistry; and Naomichi Takemata, a postdoctoral researcher in Bell’s lab, found that certain types of archaea organize their chromosomes, which store DNA, into two compartments.
For this new study, postdoctoral researcher Catherine Badel, Samson and Bell measured chromosome mutation rates in 11 species in a given genus of archaea. Their analysis showed that the DNA in one compartment, where it was stored more compactly, changed much faster than the other compartment.
The discovery is important, Bell said, because understanding DNA’s form and function could help researchers better understand all life forms, including humans. That knowledge could one day help researchers improve treatments for genetic diseases or other genetic errors.
“We need to understand how something works before we can understand how to fix it if something goes wrong,” he said.
This research builds on previous work by Bell and his collaborators, who found similarities between human and archaeal chromosomes in a previous study.
Key Similarities Discovered Between Human and Archaeal Chromosomes
Catherine Badel et al, Chromosome organization influences genome evolution in Sulfolobus archaea, Nature Microbiology (2022). DOI: 10.1038/s41564-022-01127-7
Quote: DNA evolves at different rates depending on chromosome structure (2022, June 14) Retrieved June 14, 2022 from https://phys.org/news/2022-06-dna-evolves-chromosome.html
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