Christopher A. Cullis, chair of biology at Case Western Reserve University, explains that this is the basis of his controversial research findings.
Cullis, who has spent over 40 years studying mutations within plants, most recently flax (Linum usitatissimum), has found that the environment not only weeds out harmful and useless mutations through natural selection, but actually influences helpful mutations.
Cullis published his findings in the International Journal of Genetics and Molecular Biology and repeated them in the Journal of Visualized Experiments, where he challenged other scientists to repeat his experiment themselves.
Specifically, Cullis focuses on mutations involving the appearance of a small sequence of DNA known as LIS-1 and how the environment affects these changes.
The controversy stems from the idea that the environment changes organisms as they grow and these changes are passed on.
While originally accepted, the theory was eventually thrown out because science revealed that animals pass along DNA through their gamete or sex cells, which are not affected by the environment. This concept was assumed to be the same for plants, but Cullis’s research says otherwise.
In his second study, three separate strands (the plastic strand, short strand, and tall strand) of the Stormont Cirrus variety of flax were grown under three separate conditions.
Each of the strands had been bred over multiple generations under different conditions: The plastic strand’s ancestors were grown under control conditions, the short strand’s ancestors were grown under low-nutrient conditions, and the tall strand’s ancestors were grown under high-nutrient conditions.
The experiment showed each strand responded to each condition in a different way, corresponding to the environment its ancestors were grown in. The plastic strand outgrew the other strands under control conditions, the short strand outgrew the other strands when few nutrients were available, and the tall strand grew best when nutrients were readily available.
All this information does not completely explain Cullis’s assertion that the environment can in a single generation help sift out the useful mutations.
This is where polymerase chain reaction (PCR) amplification of DNA comes in. Through this process, the researchers could see when a specific DNA sequence (in this case LIS-1) appears or disappears.
When the plastic strand is grown under low nutrient conditions, the LIS-1 sequence, which had been absent, appears and continues for future generations. Since the LIS-1 sequence helps plants survive when there is a shortage of nutrients, its presence helps confirm Cullis’s belief that the environment can act on how a plant mutates and keep helpful mutations, even within one generation.
These findings help explain why the top of a redwood is genetically different from the bottom. Young redwoods grow by the tips of the existing branches budding into meristems. Each new meristem is different from the tree because the environment has affected its genetic makeup. And as the redwood grows, the top becomes more and more genetically different from the bottom.
Due to the controversy surrounding Cullis’s findings, many scientists are hesitant to accept them as true. Cullis himself recalls at first being skeptical and thinking, “If this really works… [we can] get a plant that’s better adapted to its environment in one generation.”
These adapted plants have practical uses. Cullis hopes to identify the specific gene sequence responsible for flax’s ability to withstand harsh environments and insert it into the DNA sequence of other plants so that they too can withstand trying environments.
This would bypass the current method of genetically engineering plants, which involves isolating specific DNA sequences that control heat-resistance, cold-resistance, pest-resistance, etc., and instead narrows the effort down to one DNA sequence.
By inserting this sequence into the plant and growing it in a specific trying environment, scientists could make the plant resistant to what they want. All of that plant’s offspring would be adapted to the environment and ready to grow.
By making the plant do all the work, the price of producing better crops would be greatly reduced. This would greatly benefit developing nations that need a large supply of food in an otherwise harsh environment. The DNA sequence may no longer just help the plant survive, but can now help entire countries thrive.
Prepared by Kyle Smith, Case Western Reserve University student.
Kevin Mayhood | Newswise Science News
Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care
Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie
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...
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...
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....
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,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
17.11.2017 | Physics and Astronomy
17.11.2017 | Health and Medicine
17.11.2017 | Studies and Analyses