Navigation Links
Ancient symbiosis between animals and bacteria discovered

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
University of Vienna

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:
Related Image:
Ancient symbiosis between animals and bacteria discovered
(Date:10/29/2015)... YORK , Oct. 29, 2015 ... technology, announced a partnership with 2XU, a global ... to deliver a smart hat with advanced bio-sensing ... and other athletes to monitor key biometrics to ... the strategic partnership, the two companies will bring together ...
(Date:10/27/2015)... 2015 Synaptics Inc. (NASDAQ: SYNA ), the ... has adopted the Synaptics ® ClearPad ® ... its newest flagship smartphones, the Nexus 5X by LG ... --> --> Synaptics works closely ... collaboration in the joint development of next generation technologies. ...
(Date:10/26/2015)... -- Delta ID Inc., a company focused on bringing secure ... announced its ActiveIRIS® technology powers the iris recognition feature ... NTT DOCOMO, INC in Japan . ... include iris recognition technology, after a very successful introduction ... 2015, world,s first smartphone to have this capability. ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... ... November 25, 2015 , ... Jessica Richman and Zachary Apte, ... their initial angel funding process. Now, they are paying it forward to other ... stage investments in the microbiome space. In this, they join other successful ...
(Date:11/24/2015)... , Nov. 24, 2015 Cepheid (NASDAQ: ... speaking at the following conference, and invited investors to ... NY      Tuesday, December 1, 2015 at 11.00 ... NY      Tuesday, December 1, 2015 at 11.00 ... Conference, New York, NY      Tuesday, ...
(Date:11/24/2015)... ... November 24, 2015 , ... ... But unless it is bound to proteins, copper is also toxic to cells. ... at Worcester Polytechnic Institute (WPI) will conduct a systematic study of copper in ...
(Date:11/24/2015)... Global, Inc., a worldwide provider of clinical research services headquartered in ... company has set a new quarterly earnings record in Q3 of ... for Q3 of 2014 to Q3 of 2015.   ... with the establishment of an Asia-Pacific office ... Kingdom and Mexico , with the ...
Breaking Biology Technology: