Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Transgenics transformed

22.10.2007
Maize mini-chromosomes can add stacks of functional genes to plants

A new method of constructing artificial plant chromosomes from small rings of naturally occurring plant DNA can be used to transport multiple genes at once into embryonic plants where they are expressed, duplicated as plant cells divide, and passed on to the next generation -- a long-term goal for those interested in improving agricultural productivity.

In the October 19, 2007, issue of PLoS-Genetics, a team of academic and commercial researchers show that their "maize mini-chromosomes" (MMC) can introduce an entire "cassette" of novel genes into a plant in a way that is structurally stable and functional. Early results, the study authors say, "suggest that the MMC could be maintained indefinitely."

"This appears be the tool that agricultural scientists, and farmers, have long dreamed of," said Daphne Preuss, PhD, professor of molecular genetics and cell biology at the University of Chicago and chief scientific officer and president of Chromatin, Inc., the makers of the MMCs.

... more about:
»Chromatin »MMC »Technology »crop »maize »mini-chromosome

"This technology could be used to increase the hardiness, yield and nutritional content of crops," she said. "It could improve the production of ethanol or other biofuels. It could enable plants to make complex biochemicals, such as medicines, at very little expense."

It could also "cut one to two years out of any new transgenic project," said Preuss, who is taking a leave of absence from the University to bring this technology into the marketplace. "You get a better product faster, which saves time, reduces costs, and frees up resources."

The production of transgenic plants, including maize, has historically relied on techniques that integrate DNA fragments into a host chromosome. This can disrupt important native genes or lead to limited or unregulated expression of the added gene.

Currently, to add a single gene, plant scientists create hundreds of transgenic plants in which the new gene is randomly inserted into a plant chromosome. Then they screen the gene-altered plants to find the few that might be suitable for commercial use. If they want to add two genes, they create twice as many new plants, screen for single-gene successes, then cross breed them to get both new genes, a slow and laborious process.

Instead, Preuss and colleagues have constructed MMCs that contain DNA sequences found in maize centromeres, the chromosomal regions needed for inheritance. Rather than inserting the new genes randomly into a plant's natural chromosomes, these mini-chromosomes remain separate.

As a result, the new genes can be arranged in a defined sequence, with each gene surrounded by the desired regulatory mechanisms. This results in more consistent and controlled expression. The whole cassette of genes is passed on as a group during cell division as well as to the next generation.

In their PLoS paper, the researchers characterized the behavior of the maize mini-chromosome through four generations. Using a gene for red color as a marker, they showed that the added genes are expressed "in nearly every leaf cell, indicating stability through mitosis" -- the process in which a cell duplicates its chromosomes to generate two identical daughter cells.

They also show that the MMC is efficiently passed on through meiosis, the creation of gametes, to the next generation, at ratios "approaching Mendelian inheritance."

Taken together, the authors conclude, the maize mini-chromosome, once introduced, behaves much like an ordinary chromosome. It remains distinct from the other chromosomes. Its gene cassette is structurally stable from generation to generation. The genes it carries are expressed and it is transmitted through mitosis and meiosis.

This development has not gone unnoticed. Six years ago, Preuss and two of her post-doctoral students at the University, Gregory Copenhaver and Kevin Keith, started Chromatin to refine and apply this technology. On October 10, 2006, the United States Patent and Trademark Office issued Chromatin patent No. 7,119,250, which extends the exclusive right to use these mini-chromosomes to all plants. This includes "a crop plant," the patent states, "a commercial crop plant, a vegetable crop plant, a fruit and vine crop plant, a field crop plant."

On May 22, 2007, biotech giant Monsanto Company purchased non-exclusive rights to use Chromatin's mini-chromosome stacking technology in corn, cotton, soybeans, and canola. Chromatin is in discussions to license this technology to other companies, potentially capturing most of the US corn market.

The timing was ideal. The US, in order to limit oil imports and reduce greenhouse gasses, hopes to double its use of ethanol in fuels by 2012 and to double that twice over by 2022. Because of increased demand, corn prices rose this summer by about 50 percent over last year.

Preuss and colleagues hope to apply the technology to other plants, including sugar cane and switch grass, which could also serve as biofuel sources. They are also looking at other applications and expanding the gene carrying capacity of their mini-chromosomes. They have successfully delivered mini-chromosomes about six times the size of MMC1, suggesting that this platform can carry "a large number of genes."

John Easton | EurekAlert!
Further information:
http://www.uchospitals.edu

Further reports about: Chromatin MMC Technology crop maize mini-chromosome

More articles from Life Sciences:

nachricht Water world
20.11.2017 | Washington University in St. Louis

nachricht Carefully crafted light pulses control neuron activity
20.11.2017 | University of Illinois at Urbana-Champaign

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 “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Water world

20.11.2017 | Life Sciences

Less is more to produce top-notch 2D materials

20.11.2017 | Materials Sciences

Carefully crafted light pulses control neuron activity

20.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>