Getting out of hot water—does mobile DNA help?

January 26, 2018, Frontiers
Thermophiles, a type of extremophile, produce some of the bright colors of Grand Prismatic Spring, Yellowstone National Park. Credit: Jim Peaco, National Park Service

Extremophiles—hardy organisms living in places that would kill most life on Earth—provide fascinating insights into evolution, metabolism and even possible extraterrestrial life. A new study provides insights into how one type of extremophile, a heat-loving microbe that uses ammonia for energy production, may have been able to make the transition from hot springs to more moderate environments across the globe. The first-ever analysis of DNA of a contemporary heat-loving, ammonia-oxidizing organism, published in open-access journal Frontiers in Microbiology, reveals that evolution of the necessary adaptations may have been helped by highly mobile genetic elements and DNA exchange with a variety of other organisms.

Most are microorganisms—and many of the most extreme are archaea, an ancient group of single-celled organisms intermediate between the other two domains of life, bacteria and eukaryotes. Different archaea lineages are specialized to different extreme environments, including scalding , incredibly salty lakes, sunless deep-sea trenches and frigid Antarctic deserts. Only one branch, Thaumarchaeota, has managed to colonize very successfully the Earth's more hospitable places—but scientists don't know why.

"Thaumarchaeota are found in very large numbers in virtually all environments, including the oceans, soils, plant leaves and the human skin," says Professor Christa Schleper from the University of Vienna, Austria, who guided and initiated the study. "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?"

As a starting point to answer this question, Professor Schleper and her team isolated a Thaumarchaeota species from a hot spring in Italy then sequenced and analyzed its genome. This represents the first genome analysis of the Nitroscaldus lineage—a subgroup of heat-loving Thaumarchaeota that get their energy by oxidizing ammonia into nitrite.

The analysis revealed that the organism, Candidatus Nitrosocaldus cavascurensis, seems to represent the closest-related lineage to the last common ancestor of all Thaumarchaeota. Intriguingly, it has highly mobile DNA elements and seems to have frequently exchanged DNA with other organisms—including other archaea, viruses and possibly even bacteria.

The ability to exchange genetic material could help this archaeon to rapidly evolve. "This organism seems prone to lateral gene transfer and invasion by foreign DNA elements," says 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 in its hot ."

Many researchers assume that the first life forms on Earth evolved in hot springs. Further studies of this thermophile archaeon might help identify general mechanisms that enabled the first living cells, both bacteria and , to conquer the world.

Explore further: Which genes are crucial for the energy metabolism of Archaea?

More information: Frontiers in Microbiology, DOI: 10.3389/fmicb.2018.00028

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betterexists
not rated yet Jan 26, 2018
Compare Genomes of Both and then, Transfer Relevant DNA from 1 Group (of course, of different species) into those of the other Group, Vice Versa !
See Whether you can make them survive in such totally different environments; WHAT IS STOPPING You ?
IT IS A MUST to prove SCIENCE ASAP to Laymen ! Also, there may be unknown Dividends Waiting for Humanity, Who knows? Everything in the Petridish - May not be Completely !
torbjorn_b_g_larsson
1 / 5 (1) Jan 30, 2018
Compare Genomes of Both and then, Transfer Relevant DNA from 1 Group (of course, of different species) into those of the other Group, Vice Versa !
See Whether you can make them survive in such totally different environments; WHAT IS STOPPING You ?


It is not as easy as all that due to differences in genome arrangement and cell machinery, but it has been done by GMO methods for decades now. Something that comes to mind by you asking for huge chunk transfers is how Venter's collaboration produced the first synthetic bacterial cell by letting the gene cassettes be copied in yeast, an eukaryote.

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