The worlds smallest photosynthetic organisms, microbes that can turn sunlight and carbon dioxide into living biomass, will be in the limelight next week. Three international teams of scientists, two funded in part by the National Science Foundation (NSF), will announce the genetic blueprints for four closely related forms of these organisms, which dominate the phytoplankton, the tiny floating plants of the oceans.
The work will be reported in the August 13 online issues of Nature and the Proceedings of the National Academy of Sciences.
Much like the sequencing of the human genome, the sequencing of the genomes of three strains of Prochlorococcus and one of closely related Synechococcus should crack many mysteries about these organisms-and about phytoplankton in general.
A better understanding of phytoplankton, which play a critical role in the regulation of atmospheric carbon dioxide, will aid studies on global climate change. The metabolic machinery of these single-celled organisms could serve as a model for sustainable energy production, as they can turn sunlight into chemical energy, according to Gabrielle Rocap of the University of Washington, lead author of the Nature paper that reports the genomes of two strains of Prochlorococcus. "The four genomes that have been sequenced represent numerous strains that populate ocean waters and form the base of the food web," says Rocap. "A hundred of these organisms can fit end-to- end across the width of a human hair, but they grow in such abundance that, small as they are, at times they amount to more than 50 percent of the photosynthetic biomass of the oceans."
It behooves us "to understand exactly how, with roughly 2,000 genes, this tiny cell converts solar energy into living biomass-basic elements into life," said Sallie (Penny) Chisholm, a biological oceanographer at the Massachusetts Institute of Technology (MIT). "These cells are not just esoteric little creatures; they dominate the oceans. There are some 100 million Prochlorococcus cells per liter of seawater, and they are responsible for a significant fraction of global photosynthesis."
This research addresses in a concrete way major questions in biological oceanography at levels finer than the species level, says Phillip Taylor, director of NSFs biological oceanography program, which co- funded the research. "The work shows there is a rich and fascinating diversity of physiological capacity and adaptation in the sea, and that this diversity is not always revealed just by looking in the microscope."
Adds Raymond Orbach, director of the office of science at the Department of Energy (DOE), which funded the research, "While many questions remain, its clear that Prochlorococcus and Synechococcus play a significant role in photosynthetic ocean carbon sequestration. Having the completed genome in hand gives us a first-albeit crude-parts list to use in exploring the mechanisms for these and other critically important processes that could be directly relevant to this critical DOE mission."
In the same issue of Nature, a team led by Brian Palenik of the Scripps Institution of Oceanography, part of the University of California at San Diego, will report the sequence of Synechococcus, a co- inhabitant of ocean waters with Prochlorococcus, that has a unique form of motility.
The Prochlorococcus and Synechococcus teams collaborated closely. "We learned a tremendous amount working together," said Palenik. "By coming at it from different perspectives, we were able to see common themes in how these organisms adapted to the open ocean."
A separate report, by a team led by Frederick Partensky, at the Centre National de la Recherche Scientifique, Station Biologique de Roscoff, describes the genome of a third strain of Prochlorococcus and will be published online August 13 in the Proceedings of the National Academy of Sciences.
The work of all three teams "will allow us to better understand what differentiates the ecology of these closely related organisms through comparative genomics," said Chisholm.
Rocap and her colleagues present a kind of case study for how this might work. They report the genetic sequences for two different Prochlorococcus strains, then go on to compare them. The resulting analysis "reveals many of the genetic foundations for the observed differences in [the two strains] physiologies and vertical niche partitioning," the authors report. The latter refers to each strains slightly different ecological niche-they thrive at different depths in the oceans surface waters.
Chisholm emphasizes that, "we still dont know the functions of nearly half of these organisms genes. Were excited about unveiling those functions-particularly for those genes that are unique to the different strains-because theyll alert us to key factors important in regulating marine productivity [photosynthesis] and plankton diversity."
The idea, she says, "is to let the organisms tell us what dimensions of their environment are important in determining their distribution and abundance. This will become easier and easier as the genomes of additional strains are sequenced, and the functions of the genes are understood."
Concludes Rocap, "Right now, we dont even know the range of diversity that exists. Weve had just a glimpse of the different genome types that are out there."
This research was also sponsored by the Seaver Foundation, the Israel-US Binational Science Foundation, and FP5-Margenes.
Cheryl Dybas | NSF
How cells hack their own genes
24.08.2017 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH
What the world's tiniest 'monster truck' reveals
23.08.2017 | American Chemical Society
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
23.08.2017 | Life Sciences
23.08.2017 | Life Sciences
23.08.2017 | Physics and Astronomy