Obelisk (biology): Difference between revisions
Alexcalamaro (talk | contribs) Removing their appearance only in plants, as our viroid article says : "A recent metatranscriptomics study suggests that the host diversity of viroids and other viroid-like elements is broader than previously thought and that it would not be limited to plants' Tags: Visual edit Mobile edit Mobile web edit Advanced mobile edit |
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An '''obelisk''' is a "[[viroid]]-like element" of a type first described in a January 2024 [[preprint]], whose authors say that "Obelisks form their own distinct [[phylogenetics|phylogenetic group]]",<ref name="Zheludev-preprint">{{Cite Q|Q124389714}}</ref><ref name="Sidik">{{cite journal |last1=Sidik |first1=Saima |title='Wildly weird' RNA bits discovered infesting the microbes in our guts |url=https://www.nature.com/articles/d41586-024-00266-7 |journal=Nature |access-date=31 January 2024 |doi=10.1038/d41586-024-00266-7 |date=29 January 2024 |pmid=38291328 |archive-date=30 January 2024 |archive-url=https://web.archive.org/web/20240130213825/https://www.nature.com/articles/d41586-024-00266-7 |url-status=live }}</ref><ref name="Pennisi">{{cite journal |last1=Pennisi |first1=Elizabeth |title='It's insane': New viruslike entities found in human gut microbes |url=https://www.science.org/content/article/it-s-insane-new-viruslike-entities-found-human-gut-microbes |website=Science |access-date=31 January 2024 |doi=10.1126/science.znxt3dk |date=26 January 2024 |archive-date=30 January 2024 |archive-url=https://web.archive.org/web/20240130203652/https://www.science.org/content/article/it-s-insane-new-viruslike-entities-found-human-gut-microbes |url-status=live }}</ref><ref>{{cite journal |last=Koumoundouros |first=Tessa |title='Obelisks': Entirely New Class of Life Has Been Found in The Human Digestive System |url=https://www.sciencealert.com/obelisks-entirely-new-class-of-life-has-been-found-in-the-human-digestive-system |date=29 January 2024 |journal=[[ScienceAlert]] |url-status=live |archiveurl=https://archive.ph/wip/WuR9D |archivedate=29 January 2024 |accessdate=29 January 2024 }}</ref> as their [[RNA sequence]]s, discovered by computer-aided [[metatranscriptomics]], are not [[Homology (biology)|homologous]] with the genetic code of any other life form.<ref name="Zheludev-preprint" /> |
An '''obelisk''' is a "[[viroid]]-like element" of a type first described in a January 2024 [[preprint]], whose authors say that "Obelisks form their own distinct [[phylogenetics|phylogenetic group]]",<ref name="Zheludev-preprint">{{Cite Q|Q124389714}}</ref><ref name="Sidik">{{cite journal |last1=Sidik |first1=Saima |title='Wildly weird' RNA bits discovered infesting the microbes in our guts |url=https://www.nature.com/articles/d41586-024-00266-7 |journal=Nature |access-date=31 January 2024 |doi=10.1038/d41586-024-00266-7 |date=29 January 2024 |pmid=38291328 |archive-date=30 January 2024 |archive-url=https://web.archive.org/web/20240130213825/https://www.nature.com/articles/d41586-024-00266-7 |url-status=live }}</ref><ref name="Pennisi">{{cite journal |last1=Pennisi |first1=Elizabeth |title='It's insane': New viruslike entities found in human gut microbes |url=https://www.science.org/content/article/it-s-insane-new-viruslike-entities-found-human-gut-microbes |website=Science |access-date=31 January 2024 |doi=10.1126/science.znxt3dk |date=26 January 2024 |archive-date=30 January 2024 |archive-url=https://web.archive.org/web/20240130203652/https://www.science.org/content/article/it-s-insane-new-viruslike-entities-found-human-gut-microbes |url-status=live }}</ref><ref>{{cite journal |last=Koumoundouros |first=Tessa |title='Obelisks': Entirely New Class of Life Has Been Found in The Human Digestive System |url=https://www.sciencealert.com/obelisks-entirely-new-class-of-life-has-been-found-in-the-human-digestive-system |date=29 January 2024 |journal=[[ScienceAlert]] |url-status=live |archiveurl=https://archive.ph/wip/WuR9D |archivedate=29 January 2024 |accessdate=29 January 2024 }}</ref> as their [[RNA sequence]]s, discovered by computer-aided [[metatranscriptomics]], are not [[Homology (biology)|homologous]] with the genetic code of any other life form.<ref name="Zheludev-preprint" /> |
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With their relationship to other organisms being unknown, they are an example of the [[incertae sedis]]. |
With their relationship to other organisms being unknown, they are an example of the ''[[incertae sedis]]''. |
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== Distribution and pathology == |
== Distribution and pathology == |
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Revision as of 08:32, 1 February 2024
 | A request that this article title be changed to Obelisk (biology) is under discussion. Please do not move this article until the discussion is closed. |
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An obelisk is a "viroid-like element" of a type first described in a January 2024 preprint, whose authors say that "Obelisks form their own distinct phylogenetic group",[1][2][3][4] as their RNA sequences, discovered by computer-aided metatranscriptomics, are not homologous with the genetic code of any other life form.[1]
With their relationship to other organisms being unknown, they are an example of the incertae sedis.
Distribution and pathology
Obelisks have been found in human stool samples, and inside specimens of Streptococcus sanguinis, a species of bacteria, taken from human mouths. Some human subjects harboured obelisks for more than 300 days. The initial study showed the presence of obelisks in about 7 percent of the stool samples, and about 50 percent of saliva samples, from individuals living on all continents.[1]
The effect of obelisks on human health, if any, is yet to be determined,[2] as are issues such as their life cycles, and what factors their replication depend on.[1]
Genetics and biochemistry
Other features of obelisks include circular RNA genome assemblies with around 1000 base pairs, rod-like secondary structures which encompass the entire genome. In contrast to viroids, their RNA is translated into proteins, tentatively called "oblins". The two proteins listed the preprint have been named Oblin-1 and Oblin-2.[1]
First structural predictions say that Oblin-1 can bind metal ions and thus could be involved in cellular signalling. Oblin-2 features a binding site which is typical for protein complexes; Oblin-2 could therefore bind to enzymes of its host cells.[5]
References
- ^ a b c d e Ivan N. Zheludev; Robert C. Edgar; Maria Jose Lopez-Galiano; Marcos de la Peña; Artem Babaian; Ami S. Bhatt; Andrew Z. Fire (21 January 2024). "Viroid-like colonists of human microbiomes". bioRxiv. doi:10.1101/2024.01.20.576352. PMC 10827157. PMID 38293115. Wikidata Q124389714.
- ^ a b Sidik, Saima (29 January 2024). "'Wildly weird' RNA bits discovered infesting the microbes in our guts". Nature. doi:10.1038/d41586-024-00266-7. PMID 38291328. Archived from the original on 30 January 2024. Retrieved 31 January 2024.
- ^ Pennisi, Elizabeth (26 January 2024). "'It's insane': New viruslike entities found in human gut microbes". Science. doi:10.1126/science.znxt3dk. Archived from the original on 30 January 2024. Retrieved 31 January 2024.
- ^ Koumoundouros, Tessa (29 January 2024). "'Obelisks': Entirely New Class of Life Has Been Found in The Human Digestive System". ScienceAlert. Archived from the original on 29 January 2024. Retrieved 29 January 2024.
- ^ Sidik, Saima May; Fischer, Lars (2024-01-31). "Mysteriöse »Obelisken« befallen das Mikrobiom". Spektrum der Wissenschaft (German, originally founded in 1978 by Scientific American ) (in German). Retrieved 2024-01-31.