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Parvarchaeota
Parvarchaeota is a phylum of archaea belonging to the DPANN archaea. They have been discovered in acid mine drainage waters and later in marine sediments. The cells of these organisms are extremely small consistent with small genomes. Metagenomic techniques allow obtaining genomic sequences from non-cultured organisms, which were applied to determine this phylum. The type species is Candidatus '' Parvarchaeum acidiphilum''. They have very small cells, around 400-500 nm, and reduced genomes made up of about 1000 genes. A similar-sized archaea that has been found in the same acidic environments is Candidatus '' Microarcheum'', from the phylum Micrarchaeota. According to the phylogenetic trees Parvarchaeota may be a sister group of Thermoplasmata within Euryarchaeota or belong to DPANN, although it has also been suggested that all the DPANN archaea belong phylogenetically to Euryarchaeota. Taxonomy The currently accepted taxonomy is based on the List of Prokaryotic names with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micrarchaeota
DPANN is a super phylum of Archaea first proposed in 2013. Many members show novel signs of horizontal gene transfer from other domains of life. They are known as nanoarchaea or ultra-small archaea due to their smaller size (nanometric) compared to other archaea. DPANN is an acronym formed by the initials of the first five groups discovered, Diapherotrites, Parvarchaeota, Aenigmarchaeota, Nanoarchaeota and Nanohaloarchaeota. Later Woesearchaeota and Pacearchaeota were discovered and proposed within the DPANN superphylum. In 2017, another phylum Altiarchaeota was placed into this superphylum. The monophyly of DPANN is not considered established until now, due to the high mutation rate of the included phyla, which can lead to the artifact of the long branch attraction (LBA) where the lineages are grouped basally or artificially at the base of the phylogenetic tree without being related. These analyzes instead suggest that DPANN belongs to Euryarchaeota or is polyphyletic occupy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DPANN
DPANN is a superphylum of Archaea first proposed in 2013. Many members show novel signs of horizontal gene transfer from other domains of life. They are known as nanoarchaea or ultra-small archaea due to their smaller size (nanometric) compared to other archaea. DPANN is an acronym formed by the initials of the first five groups discovered, Diapherotrites, Parvarchaeota, Aenigmarchaeota, Nanoarchaeota and Nanohaloarchaeota. Later Woesearchaeota and Pacearchaeota were discovered and proposed within the DPANN superphylum. In 2017, another phylum Altiarchaeota was placed into this superphylum. The monophyly of DPANN is not considered established until now, due to the high mutation rate of the included phyla, which can lead to the artifact of the long branch attraction (LBA) where the lineages are grouped basally or artificially at the base of the phylogenetic tree without being related. These analyzes instead suggest that DPANN belongs to Euryarchaeota or is polyphyletic occupyi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaea
Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebacteria kingdom), but this term has fallen out of use. Archaeal cells have unique properties separating them from the other two domains, Bacteria and Eukaryota. Archaea are further divided into multiple recognized phyla. Classification is difficult because most have not been isolated in a laboratory and have been detected only by their gene sequences in environmental samples. Archaea and bacteria are generally similar in size and shape, although a few archaea have very different shapes, such as the flat, square cells of '' Haloquadratum walsbyi''. Despite this morphological similarity to bacteria, archaea possess genes and several metabolic pathways that are more closely related to those of eukaryotes, notably for the enzymes invo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaea
Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebacteria kingdom), but this term has fallen out of use. Archaeal cells have unique properties separating them from the other two domains, Bacteria and Eukaryota. Archaea are further divided into multiple recognized phyla. Classification is difficult because most have not been isolated in a laboratory and have been detected only by their gene sequences in environmental samples. Archaea and bacteria are generally similar in size and shape, although a few archaea have very different shapes, such as the flat, square cells of '' Haloquadratum walsbyi''. Despite this morphological similarity to bacteria, archaea possess genes and several metabolic pathways that are more closely related to those of eukaryotes, notably for the enzymes invo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euryarchaeota
Euryarchaeota (from Ancient Greek ''εὐρύς'' eurús, "broad, wide") is a phylum of archaea. Euryarchaeota are highly diverse and include methanogens, which produce methane and are often found in intestines, halobacteria, which survive extreme concentrations of salt, and some extremely thermophilic aerobes and anaerobes, which generally live at temperatures between 41 and 122 °C. They are separated from the other archaeans based mainly on rRNA sequences and their unique DNA polymerase. Description The ''Euryarchaeota'' are diverse in appearance and metabolic properties. The phylum contains organisms of a variety of shapes, including both rods and cocci. ''Euryarchaeota'' may appear either gram-positive or gram-negative depending on whether pseudomurein is present in the cell wall. ''Euryarchaeota'' also demonstrate diverse lifestyles, including methanogens, halophiles, sulfate-reducers, and extreme thermophiles in each. Others live in the ocean, suspended with plan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Center For Biotechnology Information
The National Center for Biotechnology Information (NCBI) is part of the United States National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the government of the United States. The NCBI is located in Bethesda, Maryland, and was founded in 1988 through legislation sponsored by US Congressman Claude Pepper. The NCBI houses a series of databases relevant to biotechnology and biomedicine and is an important resource for bioinformatics tools and services. Major databases include GenBank for DNA sequences and PubMed, a bibliographic database for biomedical literature. Other databases include the NCBI Epigenomics database. All these databases are available online through the Entrez search engine. NCBI was directed by David Lipman, one of the original authors of the BLAST sequence alignment program and a widely respected figure in bioinformatics. GenBank NCBI had responsibility for making available the GenBank DNA seq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Prokaryotic Names With Standing In Nomenclature
List of Prokaryotic names with Standing in Nomenclature (LPSN) is an online database that maintains information on the nomenclature, naming and Taxonomy (biology), taxonomy of prokaryotes, following the taxonomy requirements and rulings of the International Code of Nomenclature of Prokaryotes. The database was curated from 1997 to June 2013 by Jean P. Euzéby. From July 2013 to January 2020, LPSN was curated by Aidan C. Parte. In February 2020, a new version of LPSN was published as a service of the DSMZ, Leibniz Institute DSMZ, thereby also integrating the Prokaryotic Nomenclature Up-to-date service. References External links List of Prokaryotic names with Standing in Nomenclature [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermoplasmata
In taxonomy, the Thermoplasmata are a class of the Euryarchaeota. All are acidophiles, growing optimally at pH below 2. ''Picrophilus'' is currently the most acidophilic of all known organisms growing at a minimum pH of 0.06. Many of these organisms do not contain a cell wall, although this is not true in the case of ''Picrophilus''. Most members of Thermotoplasmata are thermophilic. Phylogeny The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI). See also * List of Archaea genera This article lists the genera of the Archaea. The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI). Phylogeny National Center for ... References Further reading Scientific journals * * * * Scientific books * * Scientific databases External links Archae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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