Phylogenomic analysis of the cystatin superfamily in eukaryotes and prokaryotes Nov 18, 2009
The analysis of numerous eukaryotic genomes has provided strong evidence for the emergence of this superfamily in the ancestor of eukaryotes ... While stefins remain encoded by a single or a small number of genes throughout the eukaryotes, the cystatins have undergone a more complex and dynamic evolution through numerous gene and domain duplications ... In the cystatin superfamily we discovered twenty vertebrate-specific and three angiosperm-specific orthologous families, indicating that... (BioMed Central)
Bacterial cotranslational targeting by FtsY Nov 14, 2009
So far, the exact function of the soluble SR in E. coli is unknown, but it has been suggested that, in contrast to eukaryotes, the prokaryotic SR might bind SRP-RNCs already in the cytosol and only then initiates membrane targeting. Results. (BioMed Central)
The message of evolution Nov 6, 2009
De Duve's "The Tree of Life" has eubacteria and archaebacteria at the root, then simple eukaryotes, then more complex multicellular organisms, then fungi and plants, then fishes, then reptiles, then mammals, and finally humans. Strikingly, de Duve speaks of an "arrow of evolution" that moves biological history through successive stages, from the "age of chemistry" to the "age of information" to the "age of the single cell" to the "age of multicellular organisms" and finally to the "age of the... (San Francisco Chronicle -- Opinion)
Earth takes a deep breath and has a growth spurt Nov 5, 2009
These advanced cells, eukaryotes, allowed some organisms to grow as much as a million times larger than their ancestors ... Fuelled by more oxygen, eukaryotes took another enormously significant stride: they started to combine into larger organisms containing multiple cells, organs and tissues. (Sydney Morning Herald -- World)
Uncovering hidden protists Nov 5, 2009
We applied a high-throughput parallel tag sequencing (454 sequencing) protocol adopted for eukaryotes to investigate protistan community complexity in two contrasting anoxic marine ecosystems (Framvaren Fjord, Norway; Cariaco deep-sea basin, Venezuela). Both sampling sites have previously been scrutinized for protistan diversity by traditional clone library construction and Sanger sequencing. (BioMed Central)
Human Biological Complexity Mechanism Found Nov 4, 2009
"But this also implies that random drift must prevail over Darwinian selection. In other words, if Darwinian selection were ruthlessly efficient in humans -- as it is in bacteria and unicellular eukaryotes -- then our level of complexity would not be possible.". The research is supported by the National Institutes of Health. (Science Daily)
Horizontal Gene Transfer and Symbio... Nov 4, 2009
Lateral Gene Transfer in Eukaryotes, Multicellular Organisms, Via Movable Elements. In multicellular organisms, the eukaryotes, horizontal gene transfer is a little more complex. (Suite101.com)
New Wrinkle In Ancient Ocean Chemistry Oct 30, 2009
The researchers argue that the presence of small amounts of oxygen may have stimulated the early evolution of eukaryotes -- organisms whose cells bear nuclei -- millions of years prior to the GOE. ... "The evolution of eukaryotes had to take place first.". (Science Daily)
Researchers Discover RNA Repair System In Bacteria Oct 23, 2009
Because the enzyme responsible for methylation in the newly-discovered RNA repair system is the Hen1 homolog in bacteria, the finding has also implications for the understanding of RNA interference and gene expression in plants, animals, and other eukaryotes ... "Hen1 is one of three essential enzymes in generating small noncoding RNAs for RNA interference in eukaryotes," Huang said ... "Our studies demonstrated that bacterial Hen1 carries out the same chemical reaction as its counterpart in... (Science Daily)
Epigenetic regulation of the honey bee transcriptome: unravelling the nature of methylated genes Oct 15, 2009
Although this process is widespread among eukaryotes, both the patterns of methylation and their relevant biological roles not only vary noticeably in different lineages, but often are poorly understood ... We discuss the implications of our findings for genome-scale regulatory network structures and the evolution of the role(s) of DNA methylation in eukaryotes. (BioMed Central)
The Importance of Extremophiles Oct 11, 2009
Some eukaryotes and archaebacteria are also Extremophiles. Dave Roberts of the London Natural History Museum Zoology Department has catalogued hundreds of , including algae, worms and fungi. (Suite101.com)
Come On In: Nuclear Barrier Less Restrictive Than Expected In New Cells Oct 8, 2009
7, 2009) When it comes to the two basic types of cells, prokaryotes and eukaryotes, compartmentalization is everything. Prokaryotes are evolutionarily ancient cells that only have a membrane surrounding their outer boundary, while the more complex eukaryotes have an outer membrane and membrane bound compartments within the cell. (Science Daily)
Glow-in-the-dark mushrooms discovered Oct 6, 2009
Fungi, along with plants, animals and protists are considered eukaryotes by biologists, meaning "true kernel," due to the packaging of the genome into the membrane-bounded compartment called the nucleus. (Simple bacteria and archaea, which lack a cell nucleus, are considered prokaryotes. (MSNBC -- Environment)
Cell's Split Personality: Synthetic Circuits Oct 5, 2009
Understanding A Cell's Split Personality Aids Synthetic Circuits. Understanding A Cell's Split Personality Aids Synthetic Circuits. (Science Daily)
Basic Cytoskeletal Proteins Sep 22, 2009
The cytoskeleton proteins in eukaryotes include microfilaments, intermediate filaments, and microtubules. A fourth category are the catenins, which are not classically considered cytoskeletal proteins, but they extend out from the cytoskeleton of one cell to the cytoskeleton of an adjacent cell by attaching to other cellular proteins called cadherins, forming cell adhesion molecule complexes. (Suite101.com)
Molecular Evidence To Support Evolu... Sep 19, 2009
The first eukaryotes had simple core machines created by importing pre-existing proteins. Over time, eukaryotes developed the potential for much greater complexity and diversity than prokaryotic cells ... Eukaryotes are more recent in life development than prokaryotes. (Suite101.com)
In Silico screening for functional candidates amongst hypothetical proteins Sep 16, 2009
Hypothetical proteins constitute a substantial fraction of proteomes of human as well as of other eukaryotes. With the general belief that the majority of hypothetical proteins are the product of pseudogenes, it is essential to have a tool with the ability of pinpointing the minority of hypothetical proteins with a high probability of being expressed. (BioMed Central)
Molecular Evidence Supports Key Tenet Of Darwin's Evolution Theory Sep 16, 2009
"Our research shows that these machines although complete and complex, were a result of evolution. Simple 'core' machines were established in the first eukaryotes by drawing on pre-existing proteins that had previously provided distinct, simplistic functions," Professor Lithgow said. As a model system, the research focused on one specific molecular machine, the TIM complex, which transports proteins into mitochondria. (Science Daily)
Researchers find molecular support for Darwin's theory Sep 16, 2009
How such sophisticated, multi-component machines could evolve has been somewhat mysterious, and highly controversial," Lithgow said. A non-Darwinian explanation, from believers of Intelligent Design, proposed these complex machines to be "irreducibly complex". In other words they are so neatly complex and complete that they couldn't have evolved but rather must have been designed by an intelligent entity. "Our research shows that these machines although complete and complex, were a result of... (India Times, India -- Health/Science)
Chemotherapy Resistance: Checkpoint Protein Provides Armor Against Cancer Drugs Sep 7, 2009
In response to DNA damage and blocked replication the process that copies DNA eukaryotes activate the DNA damage checkpoint pathway, which stops the cell cycle, buying time to repair damage and recover from stalled or collapsed replication forks. If not repaired, these errors can either kill a cell when it attempts to divide or lead to genomic instability and eventually cancer. (Science Daily)
Major Insight Into Evolution Of Life On Earth Aug 20, 2009
Eukaryotes are found in all multicellular forms of life, including humans, animals and plants ... "We thought eukaryotes always needed to be present to do it, but we were wrong.". (Science Daily)
'Swiss Army Knife' Protein Plays Unexpected Role Protecting Chromosome Tips; Possible Tie To Metastatic Cancer Aug 17, 2009
In eukaryotes or organisms whose cells have a nucleus, this job is handled. (May 4, 2007) A protein called RecQ takes on a totally opposite function in the bacteria Escherichia coli to the one it fulfills in yeast and in humans, indicating that people seeking to understand the role of. (Science Daily)
Cyanobacterial contribution to the genomes of the plastid-lacking protists Aug 11, 2009
Eukaryotic genes with cyanobacterial ancestry in plastid-lacking protists have been regarded as important evolutionary markers implicating the presence of plastids in the early evolution of eukaryotes ... We identified 12 gene families with cyanobacterial ancestry in the genomes of a taxonomically wide range of plastid-lacking eukaryotes (Phytophthora [Chromalveolata], Naegleria [Excavata], Dictyostelium [Amoebozoa], Saccharomyces and Monosiga [Opisthokonta]) using a novel phylogenetic pipeline... (BioMed Central)
Great Diversity Of Marine Plankton Drive Oceanic Photosynthesis Aug 8, 2009
Studies on marine protists are the subject of new research programs being coordinated by CNRS scientists in Roscoff, such as BioMarKs (Biodiversity of Marine euKaryotes) along European coastlines, or Tara-Oceans, the round-the-world scientific expedition on board the yacht Tara. Notes: (1): Haptophytes are unicellular organisms with a flagellum-like appendix called a haptonema. (Science Daily)
Yeast Cancer Model For Mapping Cancer Genes Aug 3, 2009
Pathways and genes that regulate proliferation rates are likely to be conserved in all eukaryotes. So, by identifying mutations that give cells a growth advantage in yeast, the simplest of eukaryotes, will help guide the search of cancer genes in humans. (Science Daily)
Surprising New Insights Into The Repair Strategies Of DNA Jul 17, 2009
Although similar in structure and appearance to bacteria, archaea share a common ancestor with eukaryotes, which include plant and animals. This kinship is at its closest in the way archaea process DNA. Although Dr Allers s discovery is at the basic biological level, it is the similarities with cancer cells that make him convinced that scientists have much more to learn from archaea. (Science Daily)
Core Nuclear Pore Elements Likely Shared By All Eukaryotes Jul 14, 2009
Now research shows that one of the most basic design principles of this new eukaryotic life-form the gatekeeper to the cell nucleus known as the nuclear pore complex is largely shared across the most distantly related eukaryotes ... The trypanosomes were at the wedding of the eukaryotes but were divorced the day after, says Rout, quoting his University of Cambridge colleague Mark C. Field, who also worked on the research ... They are defining features of eukaryotes, just as warm blood plus hair... (Science Daily)
Complex coevolutionary history of symbiotic Bacteroidales bacteria of various protists in the gut of termites Jul 9, 2009
Therefore, these Bacteroidales symbionts provide an opportunity to investigate not only the coevolutionary relationships with the host protists and their morphological evolution but also how symbiotic associations between prokaryotes and eukaryotes occur and evolve within a complex symbiotic community. Results. (BioMed Central)
Methane-producing Molecule Can Also Repair DNA Jul 4, 2009
ScienceDaily (July 3, 2009) The Archaea are single-celled organisms and a domain unto themselves, quite apart from the so called eukaryotes (bacteria and higher organisms). Many species live under extreme conditions, and carry out unique biochemical processes shared neither with bacteria nor with eukaryotes ... A research group working with Professor Thomas Carell, however, has now shown that this cofactor is also common in eukaryotes, where it performs an entirely different function:... (Science Daily)
Membrane Bound Organelles Jun 17, 2009
Eukaryotes Have Compartments for Different Cellular Functions. Organelles allow for many of the different required functions of the eukaryotic cell to be performed in specialized subcellular structures. (Suite101.com)
Sex is necessary Jun 16, 2009
Yes, bacteria do swap some bits of DNA, but "bacterial sex" doesn't begin to compare with the no-holds-barred approach of complex cells, the eukaryotes ... To understand why eukaryotes resorted to full-on sex, it would help to know when it happened ... There are plenty of eukaryotes that multiply by cloning rather than sex, but all turned only very recently. (Harper's Magazine)
Time series identify population responses to climate change Jun 1, 2009
Molecular Data Are Transforming Hypotheses on the Origin and Diversification of Eukaryotes. Yonas I. Tekle, Laura Wegener Parfrey, and Laura A. Katz. (EurekAlert!)
Systematic cloning and analysis of autophagy-related genes from the silkworm Bombyx mori May 27, 2009
Through the whole life of eukaryotes, autophagy plays an important role in various biological events including development, differentiation and determination of lifespan. A full set of genes and their encoded proteins of this evolutionarily conserved pathway have been identified in many eukaryotic organisms from yeast to mammals. (BioMed Central)
Phosphate Balance In Higher Organisms Elucidated May 18, 2009
The scientists have been able to identify the first x-ray structure of the enzyme responsible for the biosynthesis of polyphosphates in highly developed organisms (eukaryotes) and to distinguish the basic biochemical processes. The molecular catalytic processes can be accurately described based on the data obtained. (Science Daily)
Old Genes Can Learn New Tricks, Horned Beetles Show May 14, 2009
Humans are only mimicking nature here; RNA interference is also a natural method of gene regulation in eukaryotes. Moczek and Rose divided beetle larvae of both species into three treatment groups: no injection, buffer injection with nonsense RNA and buffer injection with RNA interference transcripts designed to disrupt one of three crucial developmental genes. (Science Daily)
Rise Of Oxygen Caused Earth's Earliest Ice Age May 8, 2009
"New oxygen in the atmosphere would also have stimulated weathering processes, delivering more nutrients to the seas, and may have also pushed biological evolution towards eukaryotes, which require free oxygen for important biosynthetic pathways," said Kaufman ... 5 billion years ago would have had a profound effect on Earth's surface environments, and potentially on aerobic respiration by eukaryotes. (Science Daily)
Protein That Makes Phosphate Chains In Yeast Revealed; Implications On Crops, Human Diseases Apr 30, 2009
Researchers at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, are now the first to uncover how this chain is assembled in eukaryotes (organisms whose cells have a nucleus) ... Scientists have known for a long time how bacteria make phosphate chains, but how the same process works in eukaryotes has so far remained elusive. (Science Daily)
Algae key to regulating carbon emissions Apr 10, 2009
She added that these two picoeukaryotes- photosynthetic eukaryotes thriving in salt water and freshwater- are often considered to belong to the same species but only share 90% of their genes ... Microminas and other picoeukaryotes account for only a quarter of picophytoplankton cells- plankton performing photosynthesis- but were responsible for three-quarters of net carbon production in a Pacific Ocean sampling, Worden and her fellow researchers showed in previous studies. (India Times, India)
Bioinformatics Sheds Light On Evolutionary Origin Of Rickettsia Virulence Genes Mar 20, 2009
Type IV secretion systems are membrane-spanning transporters that can act as syringes that inject virulence factors into the cells of their hosts (eukaryotes). Once introduced, these virulence factors compromise the host and may result in harmful disease, for example Legionnaires' disease (Legionella pneumophila) and Q fever (Coxiella burnetii). (Science Daily)
A comparative analysis of divergently-paired genes (DPGs) among Drosophila and vertebrate genomes Mar 12, 2009
6% of all genes) of DPGs which are remarkably conserved relative to its gene density as compared to other eukaryotes. Our survey and comparative analysis revealed different evolutionary patterns among DPGs between insect and vertebrate lineages. (BioMed Central)
