Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists offer first definitive proof of bacteria-feeding behavior in green algae

24.05.2013
Study gives look at early evolutionary event that paved way for land plants, animals

A team of researchers has captured images of green alga consuming bacteria, offering a glimpse at how early organisms dating back more than 1 billion years may have acquired free-living photosynthetic cells.


The green alga used in this study and shown here is from the genus Cymbomonas, which presumably resembles early ancestors of the group. The scale bar represents 10 micrometers.

Credit: AMNH/E. Kim

This acquisition is thought to have been a critical first step in the evolution of photosynthetic algae and land plants, which, in turn, contributed to the increase in oxygen levels in Earth's atmosphere and ocean and provided one of the conditions necessary for animal evolution.

In a paper that appears in the June 17 issue of Current Biology and is available online today, researchers identify a mechanism by which a green alga that resembles early ancestors of the group engulfs bacteria, providing conclusive evidence for a process that had been proposed but not definitely shown.

"This behavior had previously been suggested but we had not had clear microscopic evidence until this study," said Eunsoo Kim, assistant curator in the Museum's Division of Invertebrate Zoology and corresponding author on the paper. "These results offer important clues to an evolutionary event that fundamentally changed the trajectory of the evolution of not just photosynthetic algae and land plants, but also animals."

In green algae and land plants, photosynthesis, or the conversion of light into food, is carried out by a specialized cell structure known as a chloroplast. The origin of chloroplast is linked to endosymbiosis, a process in which a single-celled eukaryote—an organism whose cells contain a nucleus—captures a free-living photosynthetic cyanobacterium but does not digest it, allowing the photosynthetic cell to eventually evolve into a chloroplast. The specific feeding mechanisms for this process, however, have remained largely unknown until now.

In this study, researchers used transmission electron microscopy and feeding and staining experiments to take conclusive images showing how a basic green alga from the genus Cymbomonas feeds on bacteria. The alga draws bacterial cells into a tubular duct through a mouth-like opening and then transports these food particles into a large, acidic vacuole where digestion takes place. The complexity of this feeding system in photosynthetic modern alga suggests that this bacteria-feeding behavior, and the unique feeding apparatus to support it, descend from colorless ancestors of green algae and land plants and may have played important roles in the evolution of early photosynthetic eukaryotes, the precursors to plants like trees and shrubs that cover the Earth today.

Eunsoo Kim joined the Museum in 2012 as curator of the protist collection, which includes algae, protozoa, and fungus-like protists. A native of South Korea, Kim received her Ph.D. in botany from the University of Wisconsin-Madison and conducted postdoctoral research at Dalhousie University in Halifax, Nova Scotia. She works closely with associate curator Susan Perkins and curator Rob DeSalle as part of one of the first natural history museum microbial research programs.

Shinichiro Mauyama, currently a postdoctoral researcher at the Division of Environmental Photobiology at the National Institute for Basic Biology in Okazaki, Japan, is a co-author on this paper. In addition to Kim's laboratory at the Museum, this work was conducted in John Archibald's laboratory at Dalhousie University. Funding was provided by the American Museum of Natural History and Japan Society for the Promotion of Science.

Watch Kim talk about the new finding and see green algae in action in this video: http://www.youtube.com/watch?v=lafL_mmv3EA

Kendra Snyder | EurekAlert!
Further information:
http://www.amnh.org

More articles from Life Sciences:

nachricht Discovery of a Key Regulatory Gene in Cardiac Valve Formation
24.05.2017 | Universität Basel

nachricht Carcinogenic soot particles from GDI engines
24.05.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

Physicists discover mechanism behind granular capillary effect

24.05.2017 | Physics and Astronomy

Measured for the first time: Direction of light waves changed by quantum effect

24.05.2017 | Physics and Astronomy

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>