Ua hoʻoponopono hou ʻia ka hui ʻana o ke ola i loko o ka prokaryotes a me nā eukaryotes i ka makahiki 1977 i ka wā i hōʻike ʻia ai ke ʻano o ka rRNA sequence characterization ʻo archaea (i kapa ʻia ʻo 'archaebacteria') he "pili mamao loa i ka bacteria e like me ka bacteria me ka eukaryotes." i loko o ka eubacteria (e pili ana i nā bacteria maʻamau āpau), archaea, a me nā eukaryotes. Ua mau ka nīnau no ke kumu o nā eukaryotes. I ka manawa kūpono, ua hoʻomaka nā mea hōʻike i ke kūkulu ʻana no ka ʻohana archaeal o nā eukaryotes. ʻO ka mea hoihoi loa, ʻo ka ʻike ʻana he mau haneli he mau haneli eukaryotic signature proteins (ESPs) i loko o kā lākou genome. He kuleana koʻikoʻi ka ESP i ka hoʻomohala ʻana i ka cytoskeleton a me nā ʻano hana paʻakikī paʻakikī o nā eukaryotes. Ma kahi noiʻi holomua i paʻi ʻia ma 21 Dekemaba 2022, ua hōʻike nā mea noiʻi i ka ulu ʻana o kahi moʻomeheu waiwai o Asgard archaea paʻakikī a lākou i kiʻi ai me ka hoʻohana ʻana i ka cryo-electron tomography. Ua ʻike lākou he paʻakikī ko nā cell Asgard i ka cytoskeleton. ʻO kēia ka hōʻike ʻike maka mua loa o nā kūpuna archaeal o nā eukaryotes, kahi hana nui i ka hoʻomaopopo ʻana i ke kumu o nā eukaryotes.
A hiki i ka makahiki 1977, ua hui pū ʻia nā mea ola ma ka Honua eukaryotes (nā ʻano paʻakikī i hōʻike ʻia e ka hoʻokomo ʻana o nā mea genetic o ke kelepona i loko o kahi nucleus i wehewehe maikaʻi ʻia a me ka hele ʻana o ka cytoskeleton) a me nā prokaryotes (nā ʻano ola maʻalahi me nā mea genetic i loko o ka cytoplasm me ka ʻole o ka nucleaus i kuhikuhi ʻia, me ka bacteria a me archaebacteria). Ua manaʻo ʻia ʻo ke kelepona eukaryotes ua ulu ʻia ma kahi o 2 biliona makahiki aku nei, mai ka prokaryotes paha. Akā, pehea i puka mai ai nā eukaryotes? Pehea nā ʻano ola paʻakikī paʻakikī, e pili ana i nā ʻano ola kelepona maʻalahi? He nīnau hāmama nui kēia ma ka biology.
Ua kōkua ka holomua ʻenehana i ka biology molecular o ke gene a me ka protein i ke kumu o ka pilikia i ka makahiki 1977, ua ʻike ʻia ʻo archaea (i kapa ʻia ʻo 'archaebacteria') he ''pili loa i ka bacteria e like me ka bacteria eukaryotes.' ʻO ka hoʻokaʻawale mua ʻana o ke ola i loko o nā prokaryotes a me nā eukaryotes i hoʻokumu ʻia ma nā ʻokoʻa phenotypical ma ke kiʻekiʻe o nā organelles cell. Pono e hoʻokumu ʻia ka pilina phylogenetic ma luna o kahi mole i hoʻolaha nui ʻia. ʻO Ribosomal RNA (rRNA) kekahi o ia biomolecule i loaʻa i loko o nā ʻōnaehana hoʻopiʻi ponoʻī a me ka loli liʻiliʻi o nā kaʻina me ka manawa. ʻO ka nānā ʻana ma muli o ke ʻano o ke kaʻina rRNA e pono ai ka hui ʻana o nā mea ola i loko o ka eubacteria (ʻo ia ka bacteria maʻamau a pau), archaea, a me nā eukaryotes1.
Ma hope mai, e hoʻomaka ana nā hōʻike o ka pilina pili ma waena o archaea a me eukaryotes. I ka makahiki 1983, ua ʻike ʻia ʻo DNA-dependent RNA polymerases o archaea a me eukaryotes he ʻano like; hōʻike ʻelua i nā waiwai immunochemical like ʻole a ua loaʻa nā mea ʻelua mai kahi ʻano kūpuna maʻamau2. Ma muli o kahi kumulāʻau phylogenetic composite i manaʻo ʻia o kahi pālua protein, kahi noiʻi ʻē aʻe i paʻi ʻia i ka makahiki 1989, hōʻike ʻia ka pilina pili loa o archaea i nā eukaryotes ma mua o ka eubacteria.3. I kēia manawa, ke kumu archaeal o eukaryotes ua hoʻokumu ʻia akā ʻike ʻia nā ʻano archaeal pololei e ʻike ʻia a aʻo ʻia.
Ka ulu ʻana i nā haʻawina genomic ma hope o ka holomua ma papahana genome, hāʻawi i kahi fillip i makemake nui ʻia i kēia wahi. Ma waena o 2015-2020, ua ʻike kekahi mau haʻawina ʻo Asgard archaea lawe i nā genes kiko'ī eukaryote. Hoʻonui ʻia kā lākou genome no nā protein i manaʻo ʻia he kikoʻī no nā eukaryotes. Ua ʻike maopopo ʻia kēia mau haʻawina ʻo Asgard archaea e pili kokoke ana i ka eukaryote ma muli o ka loaʻa ʻana o nā haneli o nā ʻano eukaryotic signature proteins (ESPs) i loko o kā lākou genome.
ʻO ka hana aʻe, ʻo ia ka nānā kino ʻana i ke ʻano o ka hale waihona hale o Asgard archaea e hōʻoia i ke kuleana o nā ESP e like me ka mea i manaʻo nui ʻia he kuleana nui nā ESP i ka hoʻokumu ʻana i nā hale kelepona paʻakikī. No kēia, ua pono nā moʻomeheu waiwai nui o kēia archaea akā ʻike ʻia ʻo Asgard he paʻakikī a pohihihi. paʻakikī i ka mahiʻai ʻana i ka nui e aʻo iā lākou i loko o kahi keʻena hana. E like me ka haʻawina i hōʻike ʻia ma ka lā 21 Dekemaba 2022, ua lanakila kēia pilikia.
Ua loaʻa i nā mea noiʻi, ma hope o ʻeono mau makahiki o ka hana paʻakikī, improvised ʻenehana a ua kūleʻa i mahi ʻia i loko o ka hale hana, kahi moʻomeheu waiwai nui o 'Candidatus Lokiarchaeum ossiferum', he lālā o ka phylum Asgard. He mea kupaianaha kēia, no ka mea, ua hiki i nā mea noiʻi ke nānā a nānā i nā hale o loko o Asgard.
Ua hoʻohana ʻia ʻo Cryo-electron tomography e kiʻi i ka moʻomeheu hoʻonui. ʻO nā pūnaewele Asgard i loaʻa nā kino coccoid a me kahi pūnaewele o nā protrusions lālā. He paʻakikī ke ʻano o ka ʻili pūnaewele. Ua hoʻonui ʻia ʻo Cytoskeleton ma nā kino cell. Loaʻa i nā filament kaula ʻelua wili ʻia ʻo Lokiactin (e like me nā homologues actin i hoʻopaʻa ʻia e Lokiarchaeota). No laila, ua loaʻa i nā cell Asgard ka cytoskeleton e pili ana i ka actin paʻakikī, kahi a nā mea noiʻi i manaʻo ai, i hoʻomaka mua i ka hoʻomohala ʻana o ka mua. eukaryotes.
Ma ke ʻano he hōʻike kino kino / ʻike maka mua o nā kūpuna archaeal o nā eukaryotes, he holomua kupaianaha kēia i ka biology.
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E hoʻomaopopo ':
- ʻO Woese CR a me Fox GE, 1977. Phylogenetic structure of the prokaryotic domain: The primary kingdoms. Published November 1977. PNAS. 74 (11) 5088-5090. DOI: https://doi.org/10.1073/pnas.74.11.5088
- Huet, J., ¶ AL 1983. Loaʻa iā Archaebacteria a me nā eukaryotes nā RNA polymerases pili i ka DNA o kahi ʻano maʻamau. EMBO J. 2, 1291–1294 (1983). DOI: https://doi.org/10.1002/j.1460-2075.1983.tb01583.x
- Iwabe, N., ¶ AL 1989. Hoʻololi ʻia ka pilina o archaebacteria, eubacteria, a me eukaryotes mai nā kumulāʻau phylogenetic o nā genes i hoʻohālikelike ʻia. ʻO Proc. Natl Acad. ʻO Sci. USA 86, 9355–9359. DOI: https://doi.org/10.1073/pnas.86.23.9355
- Rodrigues-Oliveira, T., ¶ AL. 2022. ʻO Actin cytoskeleton a me ka hoʻolālā pūnaewele paʻakikī i kahi archaeon Asgard. Published: 21 December 2022. Nature (2022). DOI: https://doi.org/10.1038/s41586-022-05550-y
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