MedWorm provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest medical blog items that have been tagged with 'archaea'. Sat, 03 Sep 2011 02:40:19 +0100 http://www.medworm.com/index.php?rid=4171656&cid=t_187240_139_f&fid=38879&url=http%3A%2F%2Ffeedproxy.google.com%2F%7Er%2FVirologyBlog%2F%7E3%2FWgeXrkl55BU%2F As a college biology major during the 1970s I was taught that cells in which the genetic material is separated from the cytoplasm by a nuclear membrane – such as those of animals, fungi, plants, and protists – are called eukaryotes. In contrast, the DNA of bacteria is not bounded by such a structure, and hence these microbes are called prokaryotes, a name that means ‘before the nucleus’. This concept was accepted by biologists until the late-1970s, when Carl Woese used ribosomal RNA sequences to deduce the relationships among living organisms. He found that microorganisms previously thought to be bacteria, because they have no nucleus, were no more related to bacteria than to eukaryotes. He proposed that living organisms should be classified into three lineages, now... virology blog blogs http://www.medworm.com/rss/comments.php?id=4171656 Tue, 16 Nov 2010 18:45:15 +0100 4171656 http://www.medworm.com/index.php?rid=3998432&cid=t_187240_139_f&fid=38879&url=http%3A%2F%2Ffeedproxy.google.com%2F%7Er%2FVirologyBlog%2F%7E3%2F1uU7_uXX9N0%2F All known virus particles can be placed into one of two general categories: enveloped or non-enveloped. Viruses that fall into the former category are characterized by a lipid membrane derived from the host cell, and one or more nuclecapsid proteins that interact with the viral genome. A virus that infects an archaeal host may constitute a new category of enveloped viruses. It comprises a membrane vesicle that encloses a circular ssDNA genome which is devoid of nucleic acid-binding nucleoproteins. Examples of enveloped virions that contain nucleoproteins are shown in the figure below. These include influenza virus (left), a simple retrovirus (center), and a togavirus (right). The influenza virion contains segments of viral RNA bound to four different proteins. Retroviral RNA is bound to a... virology blog blogs http://www.medworm.com/rss/comments.php?id=3998432 Fri, 24 Sep 2010 02:09:07 +0100 3998432 http://www.medworm.com/index.php?rid=3567928&cid=t_187240_107_f&fid=35026&url=http%3A%2F%2Ffeedproxy.google.com%2F%7Er%2FTheTreeOfLife%2F%7E3%2FIy3E1lzK42g%2Farchaea-in-news-growing-trend.html Archaea, the so-called "third" branch in the tree of life, don't get in the news much but good when they do and for some reason, they are getting in the news more and more these days.  See below for some links to news stories. Coaxing Fuel From Extreme Bugs - Forbes.com Single origin of life story All Species Evolved From Single Cell, Study Finds Study proves Darwin's theory of universal common ancestry The Proof Is in the Proteins: Test Supports Universal Common Ancestor for All Life Asphalt Lake microbes Is This What Aliens Look Like? Life May Exist in Titan's Liquid Hydrocarbon Lakes Earth's Asphalt Lakes Hint at Possibility of Life on Titan Life found in liquid asphalt lake Life in the sticky lane Acid mine microbes with tiny genomes (work of Baker, Banfield, et al). Tiny microbe... The Tree of Life blogs http://www.medworm.com/rss/comments.php?id=3567928 Sat, 15 May 2010 17:37:46 +0100 3567928 http://www.medworm.com/index.php?rid=3440825&cid=t_187240_107_f&fid=35026&url=http%3A%2F%2Ffeedproxy.google.com%2F%7Er%2FTheTreeOfLife%2F%7E3%2Fwgge3dWGdA4%2Fmost-important-paper-ever-in.html Well, today in my "Microbial phylogenomics" class at UC Davis we are discussing what I think might be the most important paper (well, actually, series of papers) in the history of microbiology.  The papers are the ones where Carl Woese, George Fox and colleagues outline the evidence for the existence of a "hidden" third major branch in the tree of life - what is now known as the archaea.  The evidence for this third branch was first laid out in a series of papers in 1977 including:An ancient divergence among the bacteria. Balch WE, Magrum LJ, Fox GE, Wolfe RS, Woese CR.J Mol Evol. 1977 Aug 5;9(4):305-11. Classification of methanogenic bacteria by 16S ribosomal RNA characterization. Fox GE, Magrum LJ, Balch WE, Wolfe RS, Woese CR. Proc Natl Acad Sci U S A. 1977 Oct;74(10):4537-454... The Tree of Life blogs http://www.medworm.com/rss/comments.php?id=3440825 Tue, 06 Apr 2010 15:09:02 +0100 3440825 http://www.medworm.com/index.php?rid=3342245&cid=t_187240_139_f&fid=38879&url=http%3A%2F%2Fmedia.rawvoice.com%2Fpmn_twiv%2Fwww.twiv.tv%2FTWiV072.mp3 Hosts: Vincent Racaniello, Dickson Despommier, Alan Dove, and Rich Condit This week the TWiV team explains CRISPR/Cas, the immune system of bacteria and archaea, how novel viruses are discovered by deep sequencing of small RNAs, and the relationship between dry weather and outbreaks of West Nile virus infection. This episode is sponsored by Data Robotics Inc. Use the promotion code VINCENT to receive $50 off a Drobo or $100 off a Drobo S. Win a free Drobo S! Contest rules here. Download TWiV #72 (62 MB .mp3, 85 minutes) Subscribe to TWiV (free) in iTunes , at the Zune Marketplace, by the RSS feed, or by email. Links for this episode: Review on the CRISPR/cas system of bacteria and archaea Virus discovery by sequencing small virus-derived RNAs (paper one and two) Dry weather induces outbre... virology blog blogs http://www.medworm.com/rss/comments.php?id=3342245 Mon, 08 Mar 2010 02:30:37 +0100 3342245 http://www.medworm.com/index.php?rid=3126636&cid=t_187240_107_f&fid=35026&url=http%3A%2F%2Ffeedproxy.google.com%2F%7Er%2FTheTreeOfLife%2F%7E3%2F1ZX5NV7ZUxE%2Fmore-coverage-of-geba-phylogeny-driven.html Just a quick note here to post some links to additional stories about my new paper on "A phylogeny driven genomic encyclopedia of bacteria and archaea" which was published last week in Nature. Carl Zimmer has an article today in the New York Times "Scientists Start a Genomic Catalog of Earth’s Abundant Microbes"  about the paper and the project.  In the article he interviews me and Hans-Peter Klenk, who was a co-author and led the culturing part of the project.  A few things to note about this: It is rare to have archaea mentioned in the New York Times. There is a tree that goes along with the article which is a modified version of the tree we had in our paper.  I think theirs is very nice. Kudos to their artist There is a quote by Norm Pace generally supportive of ... The Tree of Life blogs http://www.medworm.com/rss/comments.php?id=3126636 Tue, 29 Dec 2009 09:43:20 +0100 3126636 http://www.medworm.com/index.php?rid=2505899&cid=t_187240_77_f&fid=37259&url=http%3A%2F%2Fwww.horizonpress.com%2Fblogger%2F2009%2F06%2Fbrief-notes-archaea.html A conventional view delineates cellular life into only two basic types called prokaryotes and eukaryotes. The prokaryotes are further subdivided into the Bacteria and the Archaea based on small subunit ribosomal RNA comparisons and conserved mechanisms for information processing. The study of Archaeal prokaryotes has matured rapidly in part initiated by genomic science as well as a continuing interest in the biochemistry and metabolism of extremophiles.The "concept" of Archaea arose over 30 years ago when Woese and Fox (1977) proposed that prokaryotes were not a monophyletic group (single root) because of differences between their small subunit ribosomal RNA sequences. Instead, they defined two distinct evolutionary lineages represented by the Bacteria and the Archaea (formerly called arch... Microbiology Blog: The weblog for microbiologists. blogs http://www.medworm.com/rss/comments.php?id=2505899 Fri, 19 Jun 2009 14:41:00 +0100 2505899 http://www.medworm.com/index.php?rid=2129790&cid=t_187240_77_f&fid=37259&url=http%3A%2F%2Fwww.horizonpress.com%2Fblogger%2F2009%2F01%2Farchaea-book-review.html Archaea: New Models for Prokaryotic Biology"This book compiles the essentials of archaea physiology and genetics ... and thus complements general textbooks on prokaryotic biology. ... Each chapter is concisely written and reviews the relevant up-to-date literature. A lot of information is given ... The book is highly recommended to researchers and lecturers in the field of microbiology as well as for academic libraries in life sciences."from Sabine Kleinsteuber (Leipzig) in Eng. Life Sci. 2008, 8(4): 447-448Further reading: Archaea: New Models for Prokaryotic BiologyFull range of books on microbiology at Microbiology Books (Source: Microbiology Blog: The weblog for microbiologists.) Microbiology Blog: The weblog for microbiologists. blogs http://www.medworm.com/rss/comments.php?id=2129790 Fri, 23 Jan 2009 14:31:00 +0100 2129790 http://www.medworm.com/index.php?rid=1884162&cid=t_187240_77_f&fid=37259&url=http%3A%2F%2Fwww.horizonpress.com%2Fblogger%2F2008%2F10%2Ftwin-arginine-pathway-tat.html A description of the twin-arginine translocation (Tat) pathway continues our series on protein secretion in microorganisms.The twin-arginine translocation (Tat) pathway is a protein transport system in bacteria, archaea and chloroplasts with the ability to export proteins in a fully folded conformation. Proteins are targeted to the Tat pathway by an N-terminal signal peptide containing an almost invariant twin-arginine sequence motif. Pretranslocational folding is necessitated by the incorporation of metallo-cofactors, assembly into oligomeric complexes, and presumably rapid folding kinetics. Many Tat systems comprise three functionally individual membrane proteins, termed TatA, TatB, and TatC, whereas especially Gram-positive bacteria possess minimal TatAC translocases, in which TatA func... Microbiology Blog: The weblog for microbiologists. blogs http://www.medworm.com/rss/comments.php?id=1884162 Fri, 17 Oct 2008 10:44:00 +0100 1884162 http://www.medworm.com/index.php?rid=1627068&cid=t_187240_77_f&fid=37259&url=http%3A%2F%2Fwww.horizonpress.com%2Fblogger%2F2008%2F07%2Farchaea-book-review.html Writing in the journal Microbiology Today (Society for General Microbiology, UK), Edward Bolt of the University of Nottingham, UK, reviews a new book on Archaea published by Caister Academic Press: "I particularly enjoyed a review on signal transduction in archaea, which captures the frontiersman spirit of some research into Archaea ... The chapter on DNA replication holds it own against several recent review articles in journals ... The book is timely and the publishers promise a 'state-of-the-art overview of Archaea'. In this it mostly works, and its slimness (246 pages) reflects a concise and mostly well-referenced style ... it conveys plenty of the novelty and oddity in Archaea that captures the imagination of students, researchers and PIs."For full details please visit Archaea: New Mo... Microbiology Blog: The weblog for microbiologists. blogs http://www.medworm.com/rss/comments.php?id=1627068 Wed, 16 Jul 2008 10:30:00 +0100 1627068 http://www.medworm.com/index.php?rid=1566922&cid=t_187240_77_f&fid=37259&url=http%3A%2F%2Fwww.horizonpress.com%2Fblogger%2F2008%2F06%2Fcyanobacteria-and-earth-history.html The biochemical capacity to use water as the source for electrons in photosynthesis evolved once, in a common ancestor of extant cyanobacteria. The geological record indicates that this transforming event took place early in our planet's history, at least 2450-2320 million years ago (Ma), and possibly much earlier. Geobiological interpretation of Archean (>2500 Ma) sedimentary rocks remains a challenge; available evidence indicates that life existed 3500 Ma, but the question of when oxygenic photosynthesis evolved continues to engender debate and research. A clear paleontological window on cyanobacterial evolution opened about 2000 Ma, revealing an already diverse biota of blue-greens. Cyanobacteria remained principal primary producers throughout the Proterozoic Eon (2500-543 Ma), in part ... Microbiology Blog: The weblog for microbiologists. blogs http://www.medworm.com/rss/comments.php?id=1566922 Wed, 18 Jun 2008 10:47:00 +0100 1566922 http://www.medworm.com/index.php?rid=1512310&cid=t_187240_132_f&fid=35624&url=http%3A%2F%2Fsuicyte.wordpress.com%2F2008%2F06%2F12%2Fis-it-research-or-just-data-analysis%2F Genome Technology blogs about the genome sequencing of Candidatus Korarchaeum cryptofilum, which appears to be an early-branching archaeon. Probably very interesting, although archaea are rarely the focus of my interest, I am mostly working on sequences from a species that should properly be called Candidatus Homo sapiens. What caught my eye, though, was the statment on author contributions (isn’t this the part of a paper that everybody reads first?). Anyway, this is what they say: Author contributions: J.G.E., P.R., M.K., and K.O.S. designed research; J.G.E., M.P., B.P.H., A.L., E.G., K.B., and G.W. performed research; J.G.E., M.P., D.E.G., K.S.M., Y.W., L.R., C.B.-A.,V.K., I.A., E.V.K., P.H., N.K., and K.O.S. analyzed data; and J.G.E., D.E.G., E.V.K., and K.O.S. wrote the paper. Yo... Suicyte Notes blogs http://www.medworm.com/rss/comments.php?id=1512310 Thu, 12 Jun 2008 08:41:48 +0100 1512310