Navigation Links
Ancient symbiosis between animals and bacteria discovered
Date:6/27/2011

Marine shallow water sandy bottoms on the surface appear desert-like and empty, but in the interstitial space between the sand grains a diverse fauna flourishes. In addition to bacteria and protozoa numerous animal phyla have been found here, some only here. One of the strangest members of this interstitial fauna is Paracatenula, a several millimeters long, mouth and gut-less flatworm, which is found from tropical oceans to the Mediterranean. These worms are the focus of a research project led by Jrg Ott at the Department of Marine Biology of the University of Vienna with funding from the Austrian Science Foundation (FWF). The surprising results of this research have now been published in the journal Proceedings of the National Academy of Sciences (PNAS).

In the early 1970s, at the time of the discovery of Paracatenula, it was already a mystery how the worms acquire their food without a mouth and gut. The solution to this question came unexpectedly: At deep ocean hot vents, giant mouth-less tubeworms were found. These like Paracatenula live in symbiosis with intracellular bacteria that oxidize reduced sulfur compounds. The energy obtained in this chemical process is used by the symbionts to fix inorganic carbon into biomass just like plants do using sunlight. Due to the high productivity of the symbionts, their hosts can derive all their nutrition from them.

Many animals of different phyla from several habitats have been found to live in such a symbiotic association. Compared to the great diversity of these hosts, the diversity of the microbial symbionts was strictly limited to members of only two classes, the Gamma and Epsilon Proteobacteria.

Paracatenula has Alpha-Proteobacterial "Riegeria" symbionts

One of the biggest surprises in the current study was that the symbionts of Paracatenula are indeed sulfur-oxidizing bacteria, but they are Alpha-Proteobacteria. Several other important intracellular symbionts come from this class, most notably the mitochondria, which are the crucial power plants in the cells of all higher organisms. The nitrogen-fixing root nodule bacteria of leguminous plants, as well as dangerous pathogens such as the causative agent of epidemic typhus, also belong to this class. In recent years several studies have presented evidence that the mechanisms in symbiotic and pathogenic relationships are similar or even identical. Future projects with Paracatenula and its symbionts called "Riegeria" could give fundamental insights into the mechanisms that have allowed Alpha-Poteobacteria several times to establish an intracellular lifestyle independently.

Another captivating detail of the Paracatenula Riegeria symbiosis is that the symbionts that live in specialized cells called Bacteriocytes account for up to 50 percent of the total tissue. That is significantly more than in all other known symbioses between animals and bacteria.

The Paracatenula-Riegeria symbiosis is 500 million years old

Based on genetic sequences of the symbionts the scientists have roughly extrapolated the age of the symbiosis the estimated age of 500 million years makes this symbiosis the oldest known animal bacteria association.

Comparing the phylogenies of hosts and symbionts, another subtle but non trivial detail was uncovered the worms have been passing on their symbionts to their offspring in every generation, without any symbiont switches for the last 500 million years. How this secured symbiont transmission is accomplished is the focus of the current studies in Jrg Ott's lab.


'/>"/>

Contact: Harald Gruber-Vodicka
harald.gruber@univie.ac.at
43-699-171-21909
University of Vienna
Source:Eurekalert  

Related biology news :

1. Modern genetics vs. ancient frog-killing fungus
2. Genetic based human diseases are an ancient evolutionary legacy
3. 6,000km trip to reveal clues to ancient migration
4. Dry spells spelled trouble in ancient China
5. Ancient magma superpiles may have shaped the continents
6. Ancient African exodus mostly involved men, geneticists find
7. Male crickets with bigger heads are better fighters, study reveals, echoing ancient Chinese text
8. Decline of carbon-dioxide-gobbling plankton coincided with ancient global cooling
9. University of Leicester archaeologist uncovers evidence of ancient chemical warfare
10. Mountain caribous ancient ancestry revealed
11. Ancient geologic escape hatches mistaken for tube worms
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Ancient symbiosis between animals and bacteria discovered
(Date:4/18/2017)... , April 18, 2017  Socionext Inc., a global expert ... a media edge server, the M820, which features the company,s hybrid ... software provided by Tera Probe, Inc., will be showcased during the ... the NAB show at the Las Vegas ... ...
(Date:4/11/2017)... BEACH GARDENS, Fla. , April 11, 2017 ... identity management and secure authentication solutions, today announced ... contract by Intelligence Advanced Research Projects Activity (IARPA) ... for IARPA,s Thor program. "Innovation has ... onset and IARPA,s Thor program will allow us ...
(Date:4/6/2017)... Forecasts by Product Type (EAC), Biometrics, Card-Based ... & Logistics, Government & Public Sector, Utilities / Energy ... Nuclear Power), Industrial, Retail, Business Organisation (BFSI), Hospitality & ... for a definitive report on the $27.9bn Access Control ... ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... Palo Alto, CA, USA (PRWEB) , ... October 11, 2017 , ... ... is set to take place on 7th and 8th June 2018 in San Francisco, ... and policy influencers as well as several distinguished CEOs, board directors and government officials ...
(Date:10/11/2017)... Austin, TX (PRWEB) , ... October 11, 2017 ... ... in August compared the implantation and pregnancy rates in frozen and fresh ... the contribution of progesterone and maternal age to IVF success. , After comparing ...
(Date:10/10/2017)... ... 2017 , ... Dr. Bob Harman, founder and CEO of VetStem Biopharma, ... The event entitled “Stem Cells and Their Regenerative Powers,” was held on ... DVM, MPVM was joined by two human doctors: Peter B. Hanson, M.D., Chief of ...
(Date:10/9/2017)... DIEGO , Oct. 9, 2017  BioTech ... biological mechanism by which its ProCell stem cell ... critical limb ischemia.  The Company, demonstrated that treatment ... amount of limbs saved as compared to standard ... the molecule HGF resulted in reduction of therapeutic ...
Breaking Biology Technology: