JAN 29, 2018 03:35 PM PST

Evolution may Have Been Helped Along by Mobile DNA

WRITTEN BY: Carmen Leitch

Organisms that live on the edges of existence, extremophiles, provide some insight into evolution and metabolism, and maybe even extraterrestrial life. On planet Earth, they inhabit some of the most extreme places, like thermal vents or volcanoes. New work has shown how a heat-loving microbe that eats ammonia may have evolved from a microorganism that inhabits hot springs to one that can live anywhere on the globe. Reporting in Frontiers in Microbiology, the investigators determined that pieces of DNA that can migrate, highly mobile genetic elements, may have helped the process.

Extreme environments, like hot springs, may have given birth to the first life forms. / Image credit: Pixabay

One branch of extremophile microbes has successfully colonized most places, but scientists have not known why. The most extreme microorganisms are on the archaea branch of life; they are single-celled and ancient, occupying a space between bacteria and eukaryotes. Archaea can be found in hot springs, salt lakes, freezing deserts, and deep-sea trenches.

"Thaumarchaeota are found in very large numbers in virtually all environments, including the oceans, soils, plant leaves and the human skin," said study leader Professor Christa Schleper from the University of Vienna, Austria. "We want to know what their secret is: billions of years ago, how did they adapt from hot springs, where it seems all archaea evolved, to more moderate habitats?"

To pursue that question, the team harvested a Thaumarchaeota species from an Italian hot spring. They assessed its genome, which is the first-ever analysis of a Thaumarchaeota of the Nitroscaldus lineage. They all oxidize ammonia into nitrite for energy. The scientists found that it was closely related to the last common ancestor of Thaumarchaeota. It appears to have exchanged DNA with other organisms often, and not only archaea but possibly other bacteria as well. The microbe, Candidatus Nitrosocaldus cavascurensis, has highly mobile genetic elements.
 
That feature may have enabled archaea to migrate away from hot springs. "This organism seems prone to lateral gene transfer and invasion by foreign DNA elements," noted Professor Schleper. "Such mechanisms may have also helped the ancestral lines of Thaumarchaeota to evolve and eventually radiate into moderate environments -- and N. cavascurensis may still be evolving through genetic exchange with neighboring organisms in its hot spring."

It has been suggested that the first forms of life on our planet evolved in hot springs, as discussed in the video. Additional studies of thermophiles may reveal mechanisms that underlie the evolution of the first cells, which went on to conquer the globe.


Sources: AAAS/Eurekalert! Via Frontiers, Frontiers in Microbiology

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
NOV 19, 2019
Genetics & Genomics
NOV 19, 2019
The Genetic Reasons Why Some People Need Less Sleep
Typically, people need between seven and eight hours of sleep per night to function properly. In  fact, reducing sleep by just one or two hours for a ...
NOV 19, 2019
Genetics & Genomics
NOV 19, 2019
Depression Can Cause Many Different Diseases
Major depressive disorder is a serious public health problem, thought to affect around seven percent of American adults in any given year....
NOV 19, 2019
Genetics & Genomics
NOV 19, 2019
New Tool Can Reveal Genes Underlying Rare Disorders
Finding the gene defect that resulted in an inherited disease used to be a long, painstaking process....
NOV 19, 2019
Genetics & Genomics
NOV 19, 2019
Researchers Develop a Score to Quantify the Risk of Epilepsy
It usually takes two seizures before a person can be diagnosed with epilepsy. New work can help change that....
NOV 19, 2019
Genetics & Genomics
NOV 19, 2019
Learning More About Changes in Cancer Cell Identity
Cancer cells can change their identity and can take on new functions and characteristics, which is often rooted in epigenetic alterations....
NOV 19, 2019
Genetics & Genomics
NOV 19, 2019
Evaluating the Genetic Damage Caused by Cancer Treatments
Now that we know more about the impact of some cancer treatments, they can be applied optimally....
Loading Comments...