Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


The world`s most stable genome has been identified in aphid endosymbionts


Bacteria 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 Canbäck, Kristina Näslund, 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!

Jon Hogdal | alfa
Further information:

More articles from Life Sciences:

nachricht Don't Give the Slightest Chance to Toxic Elements in Medicinal Products
23.03.2018 | Physikalisch-Technische Bundesanstalt (PTB)

nachricht North and South Cooperation to Combat Tuberculosis
22.03.2018 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Space observation with radar to secure Germany's space infrastructure

Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.

The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

New solar solutions for sustainable buildings and cities

23.03.2018 | Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

Latest News

For graphite pellets, just add elbow grease

23.03.2018 | Materials Sciences

Unique communication strategy discovered in stem cell pathway controlling plant growth

23.03.2018 | Agricultural and Forestry Science

Sharpening the X-ray view of the nanocosm

23.03.2018 | Physics and Astronomy

Science & Research
Overview of more VideoLinks >>>