 |
|
The world`s most stable genome has been identified in aphid endosymbionts
June 28, 2002Bacteria that reproduce inside aphids have not changed their genetic make-up for the last 50-70 million years. This makes the genomes of these bacteria the most stable of all organisms yet studied. This finding is presented by a team of scientists at Uppsala University, Sweden, in the latest issue of the scientific journal Science.
Under the leadership of Professor Siv Andersson, researchers Ivica Tama, Lisa Klasson, Björn Canb'ck, Kristina N'slund, Ann-Sofie Eriksson, and Johan Sandström at the Department of Molecular Evolution, Center for Evolutionary Biology, in collaboration with Professor Nancy Moran in Tucson, Arizona, have described the entire genetic make-up of a bacterium that reproduces inside aphids, Buchnera (Sg) and compared it to that of a close relative, Buchnera (Ap).
These aphid endosymbionts, so called because they live in symbiosis with aphids, are closely related to common bacteria like Salmonella, but the adaptation to the aphids have entailed a drastic reduction in the size of the genome, which now consists of only 640,000 bases, about 14% of the genome of Salmonella species.
Aphid endosymbionts produce important amino acids that are not present in the plant sap that the aphids drink. The bacteria live in a special type of cell in the body of the aphids and are transmitted from one generation to the next by being packed into the eggs of the aphides. These bacteria are believed to have lived in symbiosis with aphids for at least 150 million years. They have now become so important that aphides can no longer live without their bacteria. If aphids treated with antibiotics, they becomes sterile -- or die.
With the aid of available fossil data from aphids, it has been estimated that the aphids that harbor these two bacteria diverged from each other roughly 50-70 million years ago. Since these aphis symbionts have lived enclosed in the bodies of the aphids, this dating can also be used to determine when the bacterial endosymbionts diverged from each other. By measuring differences in the two genomes, the Uppsala scientists have been able to calculate for the first time exactly how many mutations have taken place in the genome of a bacterium in nature over a period spanning 50-70 million years. Surprisingly, it has now been shown that these tiny, isolated aphis bacteria have largely escaped the ravages of time. The biggest surprise is that the order of the genes has not changed over the past 50 million years.
This stability is in stark contrast to the genomes of Salmonella species, which change very rapidly in structure. It has been calculated that the genomic structure of Salmonella has been altered at a rate more than 2,000 times that of the aphid endosymbionts. The secret behind the extreme stability of the aphid endosymbionts probably lies in the fact that during the early process of degradation they eliminated the genes that are needed for cutting and pasting genetic material.
However, it is extremely unlikely that the aphids` stable minibacteria will ever return to a normal life outside the aphids. They are now completely controlled by the aphids, so much so that the question can be raised whether they should be seen as bacteria or rather as organs of aphides. But if that is the case, then this is the first organ that has its own genetic code!
VetenskapsrÃdet (The Swedish Research Council)
Aphid endosymbionts produce important amino acids that are not present in the plant sap that the aphids drink. The bacteria live in a special type of cell in the body of the aphids and are transmitted from one generation to the next by being packed into the eggs of the aphides. These bacteria are believed to have lived in symbiosis with aphids for at least 150 million years. They have now become so important that aphides can no longer live without their bacteria. If aphids treated with antibiotics, they becomes sterile -- or die.
With the aid of available fossil data from aphids, it has been estimated that the aphids that harbor these two bacteria diverged from each other roughly 50-70 million years ago. Since these aphis symbionts have lived enclosed in the bodies of the aphids, this dating can also be used to determine when the bacterial endosymbionts diverged from each other. By measuring differences in the two genomes, the Uppsala scientists have been able to calculate for the first time exactly how many mutations have taken place in the genome of a bacterium in nature over a period spanning 50-70 million years. Surprisingly, it has now been shown that these tiny, isolated aphis bacteria have largely escaped the ravages of time. The biggest surprise is that the order of the genes has not changed over the past 50 million years.
This stability is in stark contrast to the genomes of Salmonella species, which change very rapidly in structure. It has been calculated that the genomic structure of Salmonella has been altered at a rate more than 2,000 times that of the aphid endosymbionts. The secret behind the extreme stability of the aphid endosymbionts probably lies in the fact that during the early process of degradation they eliminated the genes that are needed for cutting and pasting genetic material.
However, it is extremely unlikely that the aphids` stable minibacteria will ever return to a normal life outside the aphids. They are now completely controlled by the aphids, so much so that the question can be raised whether they should be seen as bacteria or rather as organs of aphides. But if that is the case, then this is the first organ that has its own genetic code!
VetenskapsrÃdet (The Swedish Research Council)
Bacteria Current Events and Bacteria News RSSFactors from common human bacteria may trigger multiple sclerosis
Current research suggests that a common oral bacterium may exacerbate autoimmune disease. The related report by Nichols et al, "Unique Lipids from a Common Human Bacterium Represent a New Class of TLR2 Ligands Capable of Enhancing Autoimmunity," appears in the December 2009 issue of The American Journal of Pathology.
Exposure to both traffic, indoor pollutants puts some kids at higher risk for asthma later
New research presents strong evidence that the "synergistic" effect of early-life exposure to both outdoor traffic-related pollution and indoor endotoxin causes more harm to developing lungs than one or the other exposure alone.
New study finds MRSA on the rise in hospital outpatients
The community-associated strain of the deadly superbug MRSA-an infection-causing bacteria resistant to most common antibiotics-poses a far greater health threat than previously known and is making its way into hospitals, according to a study in the December issue of Emerging Infectious Diseases.
Researchers establish common seasonal pattern among bacterial communities in Arctic rivers
New research on bacterial communities throughout six large Arctic river ecosystems reveals predictable temporal patterns, suggesting that scientists could use these communities as markers for monitoring climate change in the polar regions.
Biologists discover bacterial defense mechanism against aggressive oxygen
Bacteria possess an ingenious mechanism for preventing oxygen from harming the building blocks of the cell.
Saving the single cysteine: new antioxidant system found
We've all read studies about the health benefits of having a life partner. The same thing is true at the molecular level, where amino acids known as cysteines are much more vulnerable to damage when single than when paired up with other cysteines.
Beyond sunlight: Explorers census 17,650 ocean species between edge of darkness and black abyss
Census of Marine Life scientists have inventoried an astonishing abundance, diversity and distribution of deep sea species that have never known sunlight - creatures that somehow manage a living in a frigid black world down to 5,000 meters (~3 miles) below the ocean waves.
Surface bacteria maintain skin's healthy balance
On the skin's surface, bacteria are abundant, diverse and constant, but inflammation is undesirable. Research at the University of California, San Diego School of Medicine now shows that the normal bacteria living on the skin surface trigger a pathway that prevents excessive inflammation after injury.
On the Trail of a Vaccine for Lyme Disease: Yale Researchers Target Tick Saliva
A protein found in the saliva of ticks helps protect mice from developing Lyme disease, Yale researchers have discovered. The findings, published in the November 19 issue of Cell Host & Microbe, may spur development of a new vaccine against infection from Lyme disease, which is spread through tick bites.
Cigarettes Harbor Many Bacteria Harmful to Human Health
Cigarettes are "widely contaminated" with bacteria, including some known to cause disease in people, concludes a new international study conducted by a University of Maryland environmental health researcher and microbial ecologists at the Ecole Centrale de Lyon in France.
More Bacteria Current Events and Bacteria News Articles
 |
A Field Guide to Bacteria (Comstock Book) by Betsey Dexter Dyer (Author) Pocket-guide to observing bacteria without a laboratory or fancy equipment. Presents all the major taxonomic groups of bacteria in a useable, accessible format for amateur naturalists who may or may not have access to a microscope. Includes ideas for planning field trips to explore bacteria in their natural environments. Illustrated, some color. Softcover, hardcover available. |
 |
Ein-O Science BioSigns Bacteria by Tedco The hands on cell and microbiology models provide magnified and cross section details. The set includes Virus, Bacteria, Plant Cell, White Blood Cell, Red Blood Cell and Animal Cell. Ein-O's I Know Guides and storage box are included. Consider using these models with a display of your own making - featuring the intricacies of cell structure, comparing and contrasting differences, investigating functions & interactions, or describing the efforts of modern medicine... a neat Science Fair Project. Virus - This hands-on interactive model provides magnified and cross-sectioned detailing of a Virus. Animal Cell - This hands-on interactive model provides magnified and cross-sectioned detailing of an Animal Cell. White Blood Cell - This hands-on interactive model provides... |
 |
Bacteria (Discovery Channel School Science) by Lynn Brunelle (Author), Barbara Ravage (Author), Lynn Brunelle (Editor), Barbara Ravage (Editor), Gareth Stevens Publishing (Editor) |
 |
Good Germs, Bad Germs: Health and Survival in a Bacterial World by Jessica Snyder Sachs (Author) Making Peace with Microbes Public sanitation and antibiotic drugs have brought about historic increases in the human life span; they have also unintentionally produced new health crises by disrupting the intimate, age-old balance between humans and the microorganisms that inhabit our bodies and our environment. As a result, antibiotic resistance now ranks among the gravest medical problems of modern times. Good Germs, Bad Germs addresses not only this issue but also what has become known as the “hygiene hypothesis”— an argument that links the over-sanitation of modern life to now-epidemic increases in immune and other disorders. In telling the story of what went terribly wrong in our war on germs, Jessica Snyder Sachs explores our emerging understanding of the symbiotic... |
 |
60 Minutes - Superbug (November 11, 2007) Airdate 11/11/07 MRSA is a superbug, a staff infection that has moved out of hospitals and nursing homes and is now infecting healthy people, sometimes killing them. That's because once the MRSA infection gets into the blood stream, it is largely resistant to antibiotics. For now, the best medicine is prevention. What does this mean? Scrubbing down school desks? Hosing down team locker rooms? Sending infected kids home? Lesley Stahl reports. This product is manufactured on demand using DVD-R recordable media. Amazon.com's standard return policy will apply. |
 |
Molecular Genetics of Bacteria (Snyder, Molecular Genetics of Bacteria) by Larry Snyder (Author), Wendy Champness (Author) This landmark volume provides the single most comprehensive and authoritative textbook on bacterial molecular genetics. Perfect for advanced undergraduate and graduate-level courses, the text presents the latest research on the subject in a clearly written and well-illustrated style. It provides descriptive background information, detailed experimental methods, examples of genetic analyses, and advanced material relevant to current applications of molecular genetics. While providing a deep understanding of bacterial molecular genetics, the material is integrated with biochemical, genomic, and structural information to broaden understanding. The approach centers on the most-studied bacteria, Escherichia coli and Bacillus subtilis. In addition, examples from other bacteria with... |
 |
Magic School Bus World of Germs Science Kit by Young Scientist Club The World of Germs- Magic School Bus Science Kit FUN |
 |
Disposable EARLOOP Face MASK, Filters Bacteria 3 Ply - (Box of 50) by EVERREADY FIRST AID Tie-on surgical face mask with high bacterial filtration efficiency (BFE), low breathing resistance, soft, odorless, non-irritating, comfortable superior fit, fiberglass free. |
 |
Essick Air #1970 Quart Bacteria Treatment by ESSICK AIR PRODUCTS QT, Humidifier Bacteria Treatment, Helps Fight Bacteria & Algae Build Up, Keeps Water Smelling Clean, EPA Registered, For Use In All Evaporative Console & Room Size Humidifiers. |
 |
Enzymatic Therapy Acidophilus Pearls (90 Pearls) by Enzymatic This formula provides a combination of Acidophilus and Bididiobacterium species to support the overall health of the intestinal tract. |
| © 2009 BrightSurf.com |