When scientists discovered a worm deep in an aquifer nearly one mile underground, they hailed it as the discovery of the deepest animal ever found. Now researchers at the American University reporting in Nature Communications have sequenced the genome of a unique animal called the "Devil Worm" because of its ability to survive in harsh, underground conditions. The Devil Worm's genome provides guidance on how the body adapts to deadly environmental conditions. Future research on how it is developing can help people learn lessons on how to adapt to a warming climate.
In 2008, Gaetan Borgoni of the University of Ghent and a geologist at the University of Princeton Tuliss Onst discovered the microscopic devil of a worm while exploring underground bacterial communities in active gold mines in South Africa. Borgoni and his team were astonished to find the worm, a complex, multicellular animal that thrives in a microbial-only environment with high temperatures, low oxygen and large amounts of methane.
Researchers named the worm Halicephalobus mephisto, in honor of Mephistopheles, an underground demon from medieval German legend Faust.
Evolutionary adaptation to heat
The devil worm is the first underground animal to have sequenced its genome. The genome provides evidence for how life can exist beneath the earth's surface and opens up a new way of understanding how life can survive beyond Earth, said John Bracht, a biology assistant at American University who heads the genome sequencing project.
The sequence revealed that the genome encodes an unusually large number of heat shock proteins known as Hsp70, which is notable because many nematode species whose genomes have been sequenced do not reveal such a large number. Hsp70 is a well-studied gene that exists in all life forms and restores cellular health due to heat damage.
Many of the Hsp70 genes in the Devil Worm genome were copies of themselves. The genome also has additional copies of AIG1
"The devil worm cannot escape; he's underground, "Bracht explained. "There is no choice but to adapt or die. We suggest that when an animal cannot escape the intense heat, it begins to make additional copies of these two genes in order to survive."
By scanning other genomes, Bracht identifies other cases in which the same two gene families, Hsp70 and AIG1, are extended. The animals he identifies are bivalve, a group of molluscs comprising mussels, oysters and mussels. They are adapted to heat like the Devil's Worm. This suggests that the pattern identified in the Devil's Worm may be more widely spread to organisms that cannot escape the surrounding heat. This work was also recently published in the Journal of Molecular Evolution with the first author of the University of AS Biology, Megan Guerin.
& # 39; The aliens are landed in the AU & # 39;
Bracht has the chance to sequence the unique genome of the worm as a doctoral student at Princeton University. He transferred the project to American University when he joined the Faculty of Biology in 2014. Two masters students in his lab, Deborah Weinstein and Sarah Allen, contributed to the study and writing of the document Nature Communications and are the first and second authors, respectively, on the manuscript. Catherine Walters-Conte, Ph.D., director of the AU Masters Program in Biotechnology, also contributed to the article.
About a decade ago, the Devil Worm was unknown and lived below the earth's surface. This is now the subject of study in scientific laboratories, including Bracht. When Bracht brought the Devil Worms from a lab in South Africa that cultivated them at his lab in the AU, he remembers telling his students that the aliens had landed in the AU. The metaphor is not a stretch. NASA supports the Devil's Worm's research on what scientists can learn about the search for life beyond Earth.
"Part of this work involves the search for" biosignatures "of life – stable chemical clues left by living beings. We focus on the ubiquitous biosignature of organic life – genomic DNA – derived from an animal that has adapted to an environment once considered habitable for a complex life: the deep earth's undergrowth, "Bracht said." Work can push us to expand our search for extraterrestrial life to "uninhabited" exoplanets "deep underground areas."
Nematodes are very suitable for studies of evolutionary adaptation, Bracht said. They have adapted to a diverse environment and are among the most abundant animals on earth. Future work involving the Devil's Worm in Bracht's laboratory will determine the function of Hsp70 by inactivating the gene to test its response to heat stress. Other work may include genetic testing for C.elegans, a type of microscopic, heat-intolerant roundworm to see if it becomes heat-resistant.
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Weinstein, DJ, Allen S, Lau M, Erasmus M, Asalone KC, Walters-Conte K, Deikus G, Sebra R, Borgonie G, van Heerden E, Onstott TC, Bracht, JR. The genome of underground nematodes reveals an evolutionary strategy for adaptation to heat. Natural Communications . DOI: 10.1038 / s41467-019-13245-8
Megan N. Guerin et al. Stress-adapted molluscs and Nematoda display converged Hsp70 and AIG1 gene families, Journal of Molecular Evolution (2019). DOI: 10.1007 / s00239-019-09900-9
Researchers consecutive genome of "devil worm" (2019, November 21)
retrieved 21 November 2019
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