[OANNES Foro] Ocean's microbiome is like the human gut's

Jue Mayo 28 12:52:50 PDT 2015

Ocean's microbiome has incredible diversity – and human likeness

by  <http://www.newscientist.com/search?rbauthors=Colin+Barras> Colin Barras

21 May 2015

http://www.newscientist.com/article/dn27578?cmpid=NLC|NSNS|2015-0528-GLOBAL&
utm_medium=NLC&utm_source=NSNS#.VWdwINJViko

 <http://www.newscientist.com/data/images/ns/cms/dn27578/dn27578-1_1200.jpg>
http://www.newscientist.com/data/images/ns/cms/dn27578/dn27578-1_1200.jpgPla
nkton collected by the Tara expedition in the Pacific Ocean with a 0.1 mm
mesh net: a mixture of multicellular organisms and single-cell protists
(Image: Christian Sardet/CNRS/Tara Expéditions)

We're a step closer to understanding the microbial community that inhabits
the ocean – and it has some striking similarities to the community that
lives inside our guts. The microbiome of the world's biggest ecosystem and
one of the smallest appear to function in surprisingly similar ways.

Microscopic plankton produce a large proportion of the oxygen in the
atmosphere – amounting to half of all oxygen produced by photosynthesis –
but we know very little about these organisms. The data collected by
researchers aboard the schooner Tara will change that. Between 2009 and
2013, the ship sailed the world's seas and oceans, collecting 35,000
plankton samples – both microbial and multicellular – from the upper layers
of the water.

The first batch of the Tara studies is published today, and it reveals that
planktonic marine life is far more diverse than anyone expected. For
example, we already knew of about 4350 species of microalgae, 1350 species
of protists and 5500 species of tiny animals, based on direct studies of
their appearance. But the new genetic evidence suggests that there are
probably three to eight times as many distinct species in each group as
currently recognised.

40 million genes

<http://www.embl.de/research/units/scb/bork/members/index.php?s_personId=CP-
60011932> Shinichi Sunagawa at the European Molecular Biology Laboratory in
Heidelberg, Germany, and his colleagues used the genetic samples from the
Tara voyage to create the Ocean Microbial Reference Gene Catalogue. It
contains over 40 million genes from more than 35,000 species.

 <http://www.newscientist.com/data/images/ns/cms/dn27578/dn27578-2_1200.jpg>
http://www.newscientist.com/data/images/ns/cms/dn27578/dn27578-2_1200.jpgThi
s male Sapphirina copepod collected in the Mediterranean sea reflects and
diffracts light through tiny plates in the cells on its surface (Image:
Christian Sardet/CNRS/Sharif Mirshak/Parafilms/Tara Expedition)

They then used the catalogue to establish the core genetic features of the
global ocean microbiome. That core turned out to be relatively small: the
researchers considered only the subset of genes found in every one of the
139 ocean microbe samples they studied, and those genes fell into just 5755
gene families.

Only one other microbiome – that
<http://www.newscientist.com/special/microbiome> of the human gut – is known
in a comparable level of detail. The two clearly occupy very different
environments: the gut lacks oxygen, for example, and has a stable
temperature, while shallow ocean water is aerobic and fluctuates in
temperature.

Even so, the genetic studies show there is a significant overlap in the way
the two microbiomes function.

In both, there was an almost identical abundance of genes involved in
replication, ion transport and cell motility.

"This certainly was rather a big surprise to us because we expected
different ecosystems would have microbial communities with functions that
would be completely different," Sunagawa said at a press conference this
week.

Universal features

It is too early to say if the similarities are coincidental or are
characteristics shared by all microbiomes. But the results hint that
microbial systems in general may behave in a similar way regardless of
exactly what environment they occupy; something that other researchers could
now begin to test, Sunagawa says.

 <http://www.newscientist.com/data/images/ns/cms/dn27578/dn27578-3_1200.jpg>
http://www.newscientist.com/data/images/ns/cms/dn27578/dn27578-3_1200.jpgA
parasitoid crustacean of the Phronima genus. It eats salps, another type of
plankton, and uses their empty husks as protective shells (Image:
M.Ormestad/Kahikai/Tara Oceans)

There were some differences, though: genes involved in defence mechanisms
and carbohydrate transport were present in both microbiomes, but were more
abundant in the human gut. Also, genes involved in energy production -
including photosynthesis - were present in both but were more abundant in
the ocean.

 <http://www.afns.ualberta.ca/StaffProfiles/AcademicProfiles/Walter.aspx>
Jens Walter at the University of Alberta in Edmonton, Canada – who was
involved in a recent analysis of the
<http://www.newscientist.com/article/dn27381-is-superdiverse-amazon-microbio
me-something-to-strive-for.html> unusual microbiome of hunter-gatherers in
the remote Venezuelan rainforest – says it is not surprising that two very
different microbiomes would function in broadly similar ways.

This is because the fundamental way in which many microbes function has not
changed much during their evolution, and it is the functions they do not
share with others that helps define the ecology of any given microbiome,
Walter says.

For instance, all forms of E. coli bacteria function in an essentially
similar way, but some are benign and some are pathogens. "The first live in
the gut of healthy people, and the latter kill you," he says.

Future Tara studies should hopefully give a more detailed picture of these
differences – as well as revealing more about how the ocean's microbial
community might be affected by climate change.

---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com
------------ próxima parte ------------
Se ha borrado un adjunto en formato HTML...
URL: <http://lista.oannes.org.pe/pipermail/oannes-oannes.org.pe/attachments/20150528/2a6cf3db/attachment.htm>
------------ próxima parte ------------
A non-text attachment was scrubbed...
Name: no disponible
Type: image/jpeg
Size: 191100 bytes
Desc: no disponible
URL: <http://lista.oannes.org.pe/pipermail/oannes-oannes.org.pe/attachments/20150528/2a6cf3db/attachment.jpeg>
------------ próxima parte ------------
A non-text attachment was scrubbed...
Name: no disponible
Type: image/jpeg
Size: 214085 bytes
Desc: no disponible
URL: <http://lista.oannes.org.pe/pipermail/oannes-oannes.org.pe/attachments/20150528/2a6cf3db/attachment-0001.jpeg>
------------ próxima parte ------------
A non-text attachment was scrubbed...
Name: no disponible
Type: image/jpeg
Size: 272035 bytes
Desc: no disponible
URL: <http://lista.oannes.org.pe/pipermail/oannes-oannes.org.pe/attachments/20150528/2a6cf3db/attachment-0002.jpeg>