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:5/9/2016)... -- Elevay is currently known as the ... high net worth professionals seeking travel for work   ... there is still no substitute for a face-to-face meeting. ... deal with a firm handshake. This is why wealthy ... citizenship via investment programs like those offered by the ...
(Date:4/26/2016)... LONDON , April 26, 2016 ... EdgeVerve Systems, a product subsidiary of Infosys (NYSE: ... a partnership to integrate the Onegini mobile security ... (Logo: http://photos.prnewswire.com/prnh/20151104/283829LOGO ) The ... enhanced security to access and transact across channels. ...
(Date:4/15/2016)... DUBLIN , April 15, 2016 ... of the,  "Global Gait Biometrics Market 2016-2020,"  report ... http://photos.prnewswire.com/prnh/20160330/349511LOGO ) , ,The global gait ... CAGR of 13.98% during the period 2016-2020. ... movement angles, which can be used to compute ...
Breaking Biology News(10 mins):
(Date:6/24/2016)... ... June 24, 2016 , ... While the majority of commercial spectrophotometers and ... and the 6000i models are higher end machines that use the more unconventional z-dimension ... light beam from the bottom of the cuvette holder. , FireflySci has developed ...
(Date:6/23/2016)... ... June 23, 2016 , ... Mosio, ... second eBook, “Clinical Trials Patient Recruitment and Retention Tips.” Partnering with experienced clinical ... eBook by providing practical tips, tools, and strategies for clinical researchers. , “The ...
(Date:6/23/2016)... , June 23, 2016   Boston Biomedical ... novel compounds designed to target cancer stemness pathways, ... been granted Orphan Drug Designation from the U.S. ... of gastric cancer, including gastroesophageal junction (GEJ) cancer. ... designed to inhibit cancer stemness pathways by targeting ...
(Date:6/23/2016)... Md. , June 23, 2016 A person ... from the crime scene to track the criminal down. ... the U.S. Food and Drug Administration (FDA) uses DNA evidence ... Sound far-fetched? It,s not. The FDA ... sequencing to support investigations of foodborne illnesses. Put as simply ...
Breaking Biology Technology: