Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Complex cells likely arose from combination of bacterial and extreme-microbe genomes

09.09.2004


New ’ring of life’ points to mergers and acquisitions between cells



According to a new report, complex cells like those in the human body probably resulted from the fusion of genomes from an ancient bacterium and a simpler microbe, Archaea, best known for its ability to withstand extreme temperatures and hostile environments. The finding provides strong evidence that complex cells arose from combinations of simpler organisms in a symbiotic effort to survive. Jim Lake and Maria Rivera, at the University of California-Los Angeles (UCLA), report their finding in the Sept. 9 issue of the journal Nature.

Scientists refer to both bacteria and Archaea as "prokaryotes"--a cell type that has no distinct nucleus to contain the genetic material, DNA, and few other specialized components. More-complex cells, known as "eukaryotes," contain a well-defined nucleus as well as compartmentalized "organelles" that carry out metabolism and transport molecules throughout the cell. Yeast cells are some of the most-primitive eukaryotes, whereas the highly specialized cells of human beings and other mammals are among the most complex.


"A major unsolved question in biology has been where eukaryotes came from, where we came from," Lake said. "The answer is that we have two parents, and we now know who those parents were." Further, he added, the results provide a new picture of evolutionary pathways. "At least 2 billion years ago, ancestors of these two diverse prokaryotic groups fused their genomes to form the first eukaryote, and in the processes two different branches of the tree of life were fused to form the ring of life," Lake said.

The work is part of an effort supported by the National Science Foundation--the federal agency that supports research and education across all disciplines of science and engineering--to re-examine historical schemes for classifying Earth’s living creatures, a process that was once based on easily observable traits. Microbes, plants or animals were said to be related if they shared certain, mostly physical, characteristics. DNA technology now allows much closer scrutiny of hereditary molecules, which provides a more accurate and detailed picture of the genetic relationships between and among living things.

"New computational tools and comparative analyses will undoubtedly find instances in which the evolutionary record will need to be set straight," said James Rodman, a program officer in NSF directorate for biology, which funded the research. "This new fellowship among microbiologists, evolutionists, and computationalists will provide a much fuller picture of the relatedness of living things."

Lake and Rivera analyzed and compared the genomes of 30 microorganisms selected from the three categories (eukaryotes, bacteria and Archaea). All of the microbes contained about the same number of genes. The researchers then used the computer to produce genome combinations that reflected the most likely ancestors of modern eukaryotes. Their analysis, they say, showed that two ancient prokaryotes--one most similar to a bacterium, and one an Archaea--combined genomes out of a mutually advantageous need to survive.

That theory, known as endosymbiosis, has been a popular explanation of how eukaryotic cells acquired smaller components to carry out cellular processes. According to the report, modern eukaryotes obtained genes required to operate the cell from the bacterial side of the family, and the information-carrying genes from the Archaea side.

Further, the authors say, the work also sheds light on the "horizontal" transfer of genes--sideways from organism to organism, rather than from parent to offspring.

Leslie Fink | EurekAlert!
Further information:
http://www.nsf.gov

More articles from Life Sciences:

nachricht Scientists unlock ability to generate new sensory hair cells
22.02.2017 | Brigham and Women's Hospital

nachricht New insights into the information processing of motor neurons
22.02.2017 | Max Planck Florida Institute for Neuroscience

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Microhotplates for a smart gas sensor

22.02.2017 | Power and Electrical Engineering

Scientists unlock ability to generate new sensory hair cells

22.02.2017 | Life Sciences

Prediction: More gas-giants will be found orbiting Sun-like stars

22.02.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>