This infernal nematode, the devil’s worm ( Halicephalobus mephisto ) lives more than 1.50 km below the Earth’s surface. It is the animal discovered at the greatest depth and that, in addition, can survive in the harshest conditions.
Now, u n team of scientists has sequenced its genome, providing clues to how it adapts to extreme environments and incredibly, why not also opening new avenues for the search for extraterrestrial life.
This peculiar nematode was not discovered until 2008, in a South African gold mine and was immediately named as the living animal found in the deepest depth. After all, who else could we find living amid the intense heat and crushing pressure of such depths? And what would I eat?
By sequencing its genome, scientists have extracted some of the secrets of the devil worm. For example, to maintain her slim half-millimeter figure, she fearlessly bites bacteria. And, since it has likely been under our feet for thousands of years, the creature has had a long time to evolve in this inhospitable habitat. Its genome shows many adaptations designed to cope with the high heat where it lives.
For example, this Extremophile has duplicated a gene that repairs fire damage until it has 70 copies of the gene. It has multiple copies of a second protective gene, leading scientists to speculate that the devil worm has wrapped itself in armor to survive the conditions in its surroundings.
The sequence revealed that the genome encodes an unusually large number of heat shock proteins known as Hsp70 , something to note because many nematode species whose genomes are sequenced do not reveal such a large number. Hsp70 is a well-studied gene that exists in all forms of life and restores cellular health due to heat damage.
The worm also has spare copies of a gene called AIG1 , which is linked to cell survival in plants and animals.
By scanning other genomes, the experts identified other cases in which the same gene families are expanded. The animals he distinguished are bivalves, a group of mollusks that include clams, oysters, and mussels. They are adapted to heat like the Devil Worm. This suggests that the pattern identified in this nematode may spread to organisms that cannot escape environmental heat.
“ It has no choice but to adapt or die. We propose that when an animal cannot escape intense heat, it begins to make extra copies of these two genes in order to survive,” the authors said in the study published in the journal Nature .
The devil’s worm has become the first genetically mapped underground creature, offering researchers hope that studying other organisms will end with equally unusual and inspiring results.
Who knows if the knowledge that the devil’s worm has just revealed can teach us something about how to live with a demon that we know quite well: climate change.
Referencia: 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 a subterrestrial nematode reveals an evolutionary strategy for adaptation to heat. Nature Communications. DOI: 10.1038/s41467-019-13245-8 / Megan N. Guerin et al. Stress Adapted Mollusca and Nematoda Exhibit Convergently Expanded Hsp70 and AIG1 Gene Families, Journal of Molecular Evolution (2019). DOI: 10.1007/s00239-019-09900-9
