Phylum of archaea
Nanoarchaeota (Greek, "dwarf or tiny ancient one") is a proposed
phylum (Candidatus Nanoarchaeota) in the domain
Archaea
[1] that currently has only one representative,
Nanoarchaeum equitans , which was discovered in a submarine
hydrothermal vent and first described in 2002.
[2]
Taxonomy
Members of the Nanoarchaeota are associated with different host organisms and environmental conditions.
[3] Despite small size, a reduced genome and limited respiration, members of the Nanoarchaeota have unusual metabolic features. For example, N. equitans has a complex and highly developed intercellular communication system.
[4]
The phylogeny of the Nanoarchaeota is anchored by its only cultured representative, Nanoarchaeum equitans , which clusters in a separate evolutionary group than other archaea,
[5]
[6] which have recently been reclassified. Further analysis has shown that N. equitans diverged early on in the evolution of Archaea, as indicated by the
16S rRNA sequence. This suggests that they occupy a deeply branching position within this group.
[7]
The currently accepted taxonomy is based on the
List of Prokaryotic names with Standing in Nomenclature (LPSN)
[8] and
National Center for Biotechnology Information (NCBI).
[9]
Phylogeny of Nanoarchaeota
[10]
[11]
[12]
"Tiddalikarchaeales"
"Parvarchaeales"
"Pacearchaeales"
"Woesearchaeales"
Class "Nanoarchaeia " Vazquez-Campos et al. 2021
[13] ["Nanoarchaea" Huber et al. 2011 ;
[14] Nanobdellia Kato et al. 2022
[15] ]
Order "Jingweiarchaeales" Rao et al. 2023
Family "Haiyanarchaeaceae" Rao et al. 2023
Genus ?"Candidatus
Haiyanarchaeum " Rao et al. 2023
"Ca. H. thermophilum" Rao et al. 2023
Family "Jingweiarchaeaceae" Rao et al. 2023
Genus ?"Candidatus
Jingweiarchaeum " Rao et al. 2023
"Ca. J. tengchongense" Rao et al. 2023
Order "Nanoarchaeales" Huber et al. 2011
[14] [Nanobdellales Kato et al. 2022
[15] ]
Family "Nanoarchaeaceae" Huber et al. 2011
[14]
Family "Nanopusillaceae" Huber et al. 2011
[14] [Nanobdellaceae Kato et al. 2022
[15] ]
Genus Nanobdella Kato et al. 2022
[15]
N. aerobiophila Kato et al. 2022
[15]
Genus "Candidatus Nanoclepta" St. John et al. 2019
[16]
"Ca. N. minuta" St. John et al. 2019
[16]
Genus "Candidatus Nanopusillus" Wurch et al. 2016
[17]
"Ca. N. acidilobi" Wurch et al. 2016
[17]
"Ca. N. stetteri" (Castelle et al. 2015) Rinke et al. 2020
[18]
Order "Tiddalikarchaeales" Vazquez-Campos et al. 2021
[13]
Family "Tiddalikarchaeaceae" Vazquez-Campos et al. 2021
[13]
Genus "Candidatus Tiddalikarchaeum" Vazquez-Campos et al. 2021
[13]
"Ca. T. anstoanum" Vazquez-Campos et al. 2021
[13]
Order "Parvarchaeales" Rinke et al. 2020
[18]
Family "Parvarchaeaceae" Rinke et al. 2020
[18] ["Acidifodinimicrobiaceae" Luo et al. 2020
[19] ]
Genus ?"Candidatus Rehaiarchaeum fermentans" Rao et al. 2023
"Ca. R. fermentans" Rao et al. 2023
Genus "Candidatus Acidifodinimicrobium" Luo et al. 2020
[19]
"Ca. A. mancum" Luo et al. 2020
[19]
Genus "Candidatus Parvarchaeum" Baker et al. 2010
[20]
?"Ca. P. tengchongense" Rao et al. 2023
"Ca. P. acidiphilum" Baker et al. 2010
[20]
"Ca. P. paracidiphilum" corrig. Baker et al. 2010
[20]
Nanoarchaeum equitans
Characteristics
Cells of N. equitans are spherical with a diameter of approximately 400
nm ,
[2] and have a very short and compact DNA sequence with the entire genome containing only 490,885
base pairs .
[6] While they have the genetic code to carry out processing and repair, they cannot carry out certain biosynthetic and metabolic processes such as lipid, amino-acid,
cofactor , or
nucleotide synthesis.
[6] Due to its limited machinery, it is an obligate parasite, the only one known in the Archaea.
[6] Because of their unusual ss rRNA sequences, they are difficult to detect using standard
polymerase chain reaction methods.
[21] Cells of N. equitans contain a normal S-layer with sixfold symmetry with a 15 nm lattice constant.
[21]
Genome structure
Small cells between 100 and 400 nm in diameter and highly streamlined genomes of 0.491-0.606 Mbp characterize nanoarchaeotes.
[22] The genomes of described nanoarchaeotes demonstrate different degrees of reduction, which is compatible with a host dependent lifestyle.
[23] Certain nanaoarchaeotes still have genes for the
CRISPR-Cas systems,
archaeal flagella , and the
gluconeogenesis pathway.
[24]
Habitat
Nanoarchaeotes are obligate symbionts that grow attached to an archaeal host known as
Ignicoccus .
[25] Both terrestrial hot springs and underwater hydrothermal vents have yielded isolates in the genus Nanoarchaeum .
[26] However, there is evidence that nanoarcheotes reside in a variety of habitats outside of marine thermal vents.
[3] Genetic evidence for members of the Nanoarchaeota has been discovered to be pervasive in terrestrial hot springs and mesophilic
hypersaline habitats using primers created based on the sequence of the 16S rRNA gene of Nanoarchaeum equitans .
[3] In addition, the discovery of ribosomal sequences in photic-zone water samples taken distant from hydrothermal vents raises the possibility that Nanoarchaeota are an ubiquitous and diversified group of Archaea that can live in habitats with a variety of temperatures and geochemical settings.
[3]
Metabolism
Although much of the metabolism of members of the Nanoarchaeota is unknown, its host is an autotroph that grows on elemental sulphur as an
electron acceptor and H2 as an
electron donor .
[26] The majority of recognized metabolic processes, such as the creation of monomers like amino acids, nucleotides, and
coenzymes , lack recognizable genes in this organism.
[26]
See also
References
^ See the
NCBI
webpage on Nanoarchaeota . Data extracted from the
"NCBI taxonomy resources" .
National Center for Biotechnology Information . Retrieved 2007-03-19 .
^
a
b
c
d Huber, Harald; Hohn, Michael J.; Rachel, Reinhard; Fuchs, Tanja; Wimmer, Verena C.; Stetter, Karl O. (May 2002).
"A new phylum of Archaea represented by a nanosized hyperthermophilic symbiont" . Nature . 417 (6884): 63–67.
Bibcode :
2002Natur.417...63H .
doi :
10.1038/417063a .
ISSN
1476-4687 .
PMID
11986665 .
S2CID
4395094 .
^
a
b
c
d Munson-McGee, Jacob H.; Field, Erin K.; Bateson, Mary; Rooney, Colleen; Stepanauskas, Ramunas; Young, Mark J. (2015-11-15). Wommack, K. E. (ed.).
"Nanoarchaeota, Their Sulfolobales Host, and Nanoarchaeota Virus Distribution across Yellowstone National Park Hot Springs" . Applied and Environmental Microbiology . 81 (22): 7860–7868.
Bibcode :
2015ApEnM..81.7860M .
doi :
10.1128/AEM.01539-15 .
ISSN
0099-2240 .
PMC
4616950 .
PMID
26341207 .
^ Jarett, Jessica K.; Nayfach, Stephen; Podar, Mircea; Inskeep, William; Ivanova, Natalia N.; Munson-McGee, Jacob; Schulz, Frederik; Young, Mark; Jay, Zackary J.; Beam, Jacob P.; Kyrpides, Nikos C.; Malmstrom, Rex R.; Stepanauskas, Ramunas; Woyke, Tanja (2018-09-17).
"Single-cell genomics of co-sorted Nanoarchaeota suggests novel putative host associations and diversification of proteins involved in symbiosis" . Microbiome . 6 (1): 161.
doi :
10.1186/s40168-018-0539-8 .
ISSN
2049-2618 .
PMC
6142677 .
PMID
30223889 .
^ Castelle, Cindy J.; Banfield, Jillian F. (2018).
"Major New Microbial Groups Expand Diversity and Alter our Understanding of the Tree of Life" . Cell . 172 (6): 1181–1197.
doi :
10.1016/j.cell.2018.02.016 .
ISSN
0092-8674 .
PMID
29522741 .
S2CID
3801477 .
^
a
b
c
d Waters, Elizabeth; Hohn, Michael J.; Ahel, Ivan; Graham, David E.; Adams, Mark D.; Barnstead, Mary; Beeson, Karen Y.; Bibbs, Lisa; Bolanos, Randall; Keller, Martin; Kretz, Keith; Lin, Xiaoying; Mathur, Eric; Ni, Jingwei; Podar, Mircea (2003-10-28).
"The genome of Nanoarchaeum equitans: Insights into early archaeal evolution and derived parasitism" . Proceedings of the National Academy of Sciences . 100 (22): 12984–12988.
Bibcode :
2003PNAS..10012984W .
doi :
10.1073/pnas.1735403100 .
ISSN
0027-8424 .
PMC
240731 .
PMID
14566062 .
^ Garrett, Roger A.; Klenk, Hans-Peter, eds. (2006-12-08).
"Archaea" . Malden, MA, USA: Blackwell Publishing Ltd.
doi :
10.1002/9780470750865 .
ISBN
978-0-470-75086-5 .
^ J.P. Euzéby.
"Phylum "Candidatus Nanoarchaeota" " .
List of Prokaryotic names with Standing in Nomenclature (LPSN). Retrieved 2021-11-17 .
^ Sayers; et al.
"Nanoarchaeota" .
National Center for Biotechnology Information (NCBI) taxonomy database. Retrieved 2021-06-05 .
^
"GTDB release 08-RS214" .
Genome Taxonomy Database . Retrieved 6 December 2021 .
^
"ar53_r214.sp_label" .
Genome Taxonomy Database . Retrieved 10 May 2023 .
^
"Taxon History" .
Genome Taxonomy Database . Retrieved 6 December 2021 .
^
a
b
c
d
e Vázquez-Campos, Xabier; Kinsela, Andrew S.; Bligh, Mark W.; Payne, Timothy E.; Wilkins, Marc R.; Waite, T. David (2021).
"Genomic Insights Into the Archaea Inhabiting an Australian Radioactive Legacy Site" . Frontiers in Microbiology . 12 : 732575.
doi :
10.3389/fmicb.2021.732575 .
ISSN
1664-302X .
PMC
8561730 .
PMID
34737728 .
^
a
b
c
d Trujillo, Martha E; Dedysh, Svetlana; DeVos, Paul; Hedlund, Brian; Kämpfer, Peter; Rainey, Fred A; Whitman, William B, eds. (2015-04-17).
Bergey's Manual of Systematics of Archaea and Bacteria (1 ed.). Wiley.
doi :
10.1002/9781118960608.obm00129 .
ISBN
978-1-118-96060-8 .
^
a
b
c
d
e Kato, Shingo; Ogasawara, Ayaka; Itoh, Takashi; Sakai, Hiroyuki D.; Shimizu, Michiru; Yuki, Masahiro; Kaneko, Masanori; Takashina, Tomonori; Ohkuma, MoriyaYR 2022 (2022).
"Nanobdella aerobiophila gen. nov., sp. nov., a thermoacidophilic, obligate ectosymbiotic archaeon, and proposal of Nanobdellaceae fam. nov., Nanobdellales ord. nov. and Nanobdellia class. nov" . International Journal of Systematic and Evolutionary Microbiology . 72 (8): 005489.
doi :
10.1099/ijsem.0.005489 .
ISSN
1466-5034 .
PMID
35993221 .
S2CID
251720962 . {{
cite journal }}
: CS1 maint: numeric names: authors list (
link )
^
a
b St. John, Emily; Liu, Yitai; Podar, Mircea; Stott, Matthew B.; Meneghin, Jennifer; Chen, Zhiqiang; Lagutin, Kirill; Mitchell, Kevin; Reysenbach, Anna-Louise (2019-01-01).
"A new symbiotic nanoarchaeote (Candidatus Nanoclepta minutus) and its host (Zestosphaera tikiterensis gen. nov., sp. nov.) from a New Zealand hot spring" . Systematic and Applied Microbiology . Taxonomy of uncultivated Bacteria and Archaea. 42 (1): 94–106.
doi :
10.1016/j.syapm.2018.08.005 .
ISSN
0723-2020 .
OSTI
1470848 .
PMID
30195930 .
S2CID
52178746 .
^
a
b Wurch, Louie; Giannone, Richard J.; Belisle, Bernard S.; Swift, Carolyn; Utturkar, Sagar; Hettich, Robert L.; Reysenbach, Anna-Louise; Podar, Mircea (2016-07-05).
"Genomics-informed isolation and characterization of a symbiotic Nanoarchaeota system from a terrestrial geothermal environment" . Nature Communications . 7 (1): 12115.
Bibcode :
2016NatCo...712115W .
doi :
10.1038/ncomms12115 .
ISSN
2041-1723 .
PMC
4935971 .
PMID
27378076 .
^
a
b
c Rinke, Christian; Chuvochina, Maria; Mussig, Aaron J.; Chaumeil, Pierre-Alain; Davin, Adrian A.; Waite, David W.; Whitman, William B.; Parks, Donovan H.; Hugenholtz, Philip (2021-02-17).
"Resolving widespread incomplete and uneven archaeal classifications based on a rank-normalized genome-based taxonomy" . Nature Microbiology . 6 (7): 946–959.
bioRxiv
10.1101/2020.03.01.972265 .
doi :
10.1038/s41564-021-00918-8 .
PMID
34155373 .
S2CID
231984712 .
^
a
b
c Luo, Zhen-Hao; Li, Qi; Lai, Yan; Chen, Hao; Liao, Bin; Huang, Li-nan (2020).
"Diversity and Genomic Characterization of a Novel Parvarchaeota Family in Acid Mine Drainage Sediments" . Frontiers in Microbiology . 11 : 612257.
doi :
10.3389/fmicb.2020.612257 .
ISSN
1664-302X .
PMC
7779479 .
PMID
33408709 .
^
a
b
c Baker, Brett J.; Comolli, Luis R.; Dick, Gregory J.; Hauser, Loren J.; Hyatt, Doug; Dill, Brian D.; Land, Miriam L.; VerBerkmoes, Nathan C.; Hettich, Robert L.; Banfield, Jillian F. (2010-05-11).
"Enigmatic, ultrasmall, uncultivated Archaea" . Proceedings of the National Academy of Sciences . 107 (19): 8806–8811.
Bibcode :
2010PNAS..107.8806B .
doi :
10.1073/pnas.0914470107 .
ISSN
0027-8424 .
PMC
2889320 .
PMID
20421484 .
^
a
b Huber, Harald; Hohn, Michael J.; Rachel, Reinhard; Fuchs, Tanja; Wimmer, Verena C.; Stetter, Karl O. (2002-05-02).
"A new phylum of Archaea represented by a nanosized hyperthermophilic symbiont" . Nature . 417 (6884): 63–67.
Bibcode :
2002Natur.417...63H .
doi :
10.1038/417063a .
ISSN
0028-0836 .
PMID
11986665 .
S2CID
4395094 .
^
"Nanoarchaeota - an overview | ScienceDirect Topics" . www.sciencedirect.com . Retrieved 2023-04-08 .
^
"Nanoarchaeota - an overview | ScienceDirect Topics" . www.sciencedirect.com . Retrieved 2023-04-08 .
^
"Nanoarchaeota - an overview | ScienceDirect Topics" . www.sciencedirect.com . Retrieved 2023-04-08 .
^ Huber, Harald; Hohn, Michael J.; Rachel, Reinhard; Stetter, Karl O. (2006), Dworkin, Martin; Falkow, Stanley; Rosenberg, Eugene; Schleifer, Karl-Heinz (eds.),
"Nanoarchaeota" , The Prokaryotes: Volume 3: Archaea. Bacteria: Firmicutes, Actinomycetes , New York, NY: Springer, pp. 274–280,
doi :
10.1007/0-387-30743-5_14 ,
ISBN
978-0-387-30743-5 , retrieved 2023-04-08
^
a
b
c Amils, Ricardo (2011),
"Nanoarchaeota" , in Gargaud, Muriel; Amils, Ricardo; Quintanilla, José Cernicharo; Cleaves, Henderson James (Jim) (eds.), Encyclopedia of Astrobiology , Berlin, Heidelberg: Springer, p. 1106,
doi :
10.1007/978-3-642-11274-4_1040 ,
ISBN
978-3-642-11274-4 , retrieved 2023-04-08
Further reading
Clingenpeel, Scott; Kan, Jinjun; Macur, Richard E.; Woyke, Tanja; et al. (11 September 2013).
"Yellowstone Lake Nanoarchaeota" . Frontiers in Microbiology . 4 : 274.
doi :
10.3389/fmicb.2013.00274 .
PMC
3769629 .
PMID
24062731 .
Hohn, MJ; Hedlund BP; Huber H (2002). "Detection of 16S rDNA sequences representing the novel phylum 'Nanoarchaeota': indication for a wide distribution in high temperature biotopes". Syst. Appl. Microbiol . 25 (4): 551–554.
doi :
10.1078/07232020260517698 .
PMID
12583716 .
Huber, H; Hohn MJ; Rachel R; Fuchs T; et al. (2002). "A new phylum of Archaea represented by a nanosized hyperthermophilic symbiont". Nature . 417 (6884): 63–67.
Bibcode :
2002Natur.417...63H .
doi :
10.1038/417063a .
PMID
11986665 .
S2CID
4395094 .
Stackebrandt, E; Frederiksen W; Garrity GM; Grimont PA; et al. (2002). "Report of the ad hoc committee for the re-evaluation of the species definition in bacteriology". Int. J. Syst. Evol. Microbiol . 52 (Pt 3): 1043–1047.
doi :
10.1099/ijs.0.02360-0 .
PMID
12054223 .
Christensen, H; Bisgaard M; Frederiksen W; Mutters R; et al. (2001).
"Is characterization of a single isolate sufficient for valid publication of a new genus or species? Proposal to modify recommendation 30b of the Bacteriological Code (1990 Revision)" . Int. J. Syst. Evol. Microbiol . 51 (Pt 6): 2221–5.
doi :
10.1099/00207713-51-6-2221 .
PMID
11760965 .
Gurtler, V; Mayall BC (2001). "Genomic approaches to typing, taxonomy and evolution of bacterial isolates". Int. J. Syst. Evol. Microbiol . 51 (Pt 1): 3–16.
doi :
10.1099/00207713-51-1-3 .
PMID
11211268 .
Dalevi, D; Hugenholtz P; Blackall LL (2001).
"A multiple-outgroup approach to resolving division-level phylogenetic relationships using 16S rDNA data" . Int. J. Syst. Evol. Microbiol . 51 (Pt 2): 385–91.
doi :
10.1099/00207713-51-2-385 .
PMID
11321083 .
Keswani, J; Whitman WB (2001).
"Relationship of 16S rRNA sequence similarity to DNA hybridization in prokaryotes" . Int. J. Syst. Evol. Microbiol . 51 (Pt 2): 667–78.
doi :
10.1099/00207713-51-2-667 .
PMID
11321113 .
Young, JM (2001). "Implications of alternative classifications and horizontal gene transfer for bacterial taxonomy". Int. J. Syst. Evol. Microbiol . 51 (Pt 3): 945–53.
doi :
10.1099/00207713-51-3-945 .
PMID
11411719 .
Christensen, H; Angen O; Mutters R; Olsen JE; et al. (2000).
"DNA-DNA hybridization determined in micro-wells using covalent attachment of DNA" . Int. J. Syst. Evol. Microbiol . 50 (3): 1095–102.
doi :
10.1099/00207713-50-3-1095 .
PMID
10843050 .
Xu, HX; Kawamura Y; Li N; Zhao L; et al. (2000).
"A rapid method for determining the G+C content of bacterial chromosomes by monitoring fluorescence intensity during DNA denaturation in a capillary tube" . Int. J. Syst. Evol. Microbiol . 50 (4): 1463–9.
doi :
10.1099/00207713-50-4-1463 .
PMID
10939651 .
Young, JM (2000).
"Suggestions for avoiding on-going confusion from the Bacteriological Code" . Int. J. Syst. Evol. Microbiol . 50 (4): 1687–9.
doi :
10.1099/00207713-50-4-1687 .
PMID
10939677 .
Hansmann, S; Martin W (2000).
"Phylogeny of 33 ribosomal and six other proteins encoded in an ancient gene cluster that is conserved across prokaryotic genomes: influence of excluding poorly alignable sites from analysis" . Int. J. Syst. Evol. Microbiol . 50 (4): 1655–63.
doi :
10.1099/00207713-50-4-1655 .
PMID
10939673 .
Tindall, BJ (1999).
"Proposal to change the Rule governing the designation of type strains deposited under culture collection numbers allocated for patent purposes" . Int. J. Syst. Bacteriol . 49 (3): 1317–1319.
doi :
10.1099/00207713-49-3-1317 .
PMID
10490293 .
Tindall, BJ (1999).
"Proposal to change Rule 18a, Rule 18f and Rule 30 to limit the retroactive consequences of changes accepted by the ICSB" . Int. J. Syst. Bacteriol . 49 (3): 1321–1322.
doi :
10.1099/00207713-49-3-1321 .
PMID
10425797 .
Tindall, BJ (1999).
"Misunderstanding the Bacteriological Code" . Int. J. Syst. Bacteriol . 49 (3): 1313–1316.
doi :
10.1099/00207713-49-3-1313 .
PMID
10425796 .
Tindall, BJ (1999).
"Proposals to update and make changes to the Bacteriological Code" . Int. J. Syst. Bacteriol . 49 (3): 1309–1312.
doi :
10.1099/00207713-49-3-1309 .
PMID
10425795 .
Palys, T; Nakamura LK; Cohan FM (1997).
"Discovery and classification of ecological diversity in the bacterial world: the role of DNA sequence data" . Int. J. Syst. Bacteriol . 47 (4): 1145–1156.
doi :
10.1099/00207713-47-4-1145 .
PMID
9336922 .
Euzeby, JP (1997).
"List of Bacterial Names with Standing in Nomenclature: a folder available on the Internet" . Int. J. Syst. Bacteriol . 47 (2): 590–592.
doi :
10.1099/00207713-47-2-590 .
PMID
9103655 .
Clayton, RA; Sutton G; Hinkle PS Jr; Bult C; Fields C (1995).
"Intraspecific variation in small-subunit rRNA sequences in GenBank: why single sequences may not adequately represent prokaryotic taxa" . Int. J. Syst. Bacteriol . 45 (3): 595–599.
doi :
10.1099/00207713-45-3-595 .
PMID
8590690 .
Murray, RG; Schleifer KH (1994).
"Taxonomic notes: a proposal for recording the properties of putative taxa of procaryotes" . Int. J. Syst. Bacteriol . 44 (1): 174–176.
doi :
10.1099/00207713-44-1-174 .
PMID
8123559 .
Winker, S; Woese CR (1991). "A definition of the domains Archaea, Bacteria and Eucarya in terms of small subunit ribosomal RNA characteristics". Syst. Appl. Microbiol . 14 (4): 305–10.
doi :
10.1016/s0723-2020(11)80303-6 .
PMID
11540071 .
Woese, CR; Kandler O; Wheelis ML (1990).
"Towards a natural system of organisms: proposal for the domains Archaea, Bacteria, and Eucarya" . Proc. Natl. Acad. Sci. USA . 87 (12): 4576–4579.
Bibcode :
1990PNAS...87.4576W .
doi :
10.1073/pnas.87.12.4576 .
PMC
54159 .
PMID
2112744 .
Achenbach-Richter, L; Woese CR (1988). "The ribosomal gene spacer region in archaebacteria". Syst. Appl. Microbiol . 10 (3): 211–4.
doi :
10.1016/s0723-2020(88)80002-x .
PMID
11542149 .
McGill, TJ; Jurka J; Sobieski JM; Pickett MH; et al. (1986). "Characteristic archaebacterial 16S rRNA oligonucleotides". Syst. Appl. Microbiol . 7 (2–3): 194–7.
doi :
10.1016/S0723-2020(86)80005-4 .
PMID
11542064 .
Woese, CR; Olsen GJ; Hahn, C. M.; Zillig, W; et al. (1984). "The phylogenetic relationships of three sulfur dependent archaebacteria". Syst. Appl. Microbiol . 5 : 97–105.
doi :
10.1016/S0723-2020(84)80054-5 .
PMID
11541975 .
Woese, CR; Fox GE (1977).
"Phylogenetic structure of the prokaryotic domain: the primary kingdoms" . Proc. Natl. Acad. Sci. USA . 74 (11): 5088–5090.
Bibcode :
1977PNAS...74.5088W .
doi :
10.1073/pnas.74.11.5088 .
PMC
432104 .
PMID
270744 .
External links
Extant
life phyla/divisions by domain