A British study shows that gene editing does not work as well as previously assumed. Experiments using the cells of mice and humans resulted in numerous unwanted mutations.
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The molecular biological gene editing CRISPR/Cas9 method regularly causes unwanted mutations. This also happens in areas of the genome far from the target areas that medical researchers and molecular biologists may seek to change using this promising innovative tool.
Since the discovery of CRISPR-Cas9 by Emmanuelle Charpentier and Jennifer Doudna in 2011, gene editing has been considered a decisive scientific breakthrough by medical doctors and molecular biologists.
Gene editing can theoretically also be used in plant breeding and numerous other areas of molecular biological research. But it is probably not that simple in practice.
Not the entire genome in view
The authors note that so far "exploration of Cas9-induced genetic alterations has been limited to the immediate vicinity of the target site and distal off-target sequences, leading to the conclusion that CRISPR–Cas9 was reasonably specific."
Gene editing with Zebrafish emryos: Similar tests with mice cells resulted in unwanted mutationsImage: picture-alliance/dpa/Max-Delbrück-Centrum für Molekulare Medizin
But now the researchers have carried out what is known as "long-read sequencing and long-range PCR genotyping." This means they use the polymerase chain reaction (PCR) technique, which is usually used to multiply gene segments, and then analyze individual genes to examine larger areas of the genome after the use of gene scissors.
And they found that the use of CRISPR/Cas9 also leads to extinction and damage very far from the desired target region.
New diseases as a result?
According to the researchers, this damage could have "pathogenetic consequences," which can in turn cause new hereditary diseases.
The researchers used mouse embryonic stem cells, mouse hematopoietic progenitors and a human differentiated cell line for their experiments.
The authors of the study warn that physicians who want to use CRISPR/Cas9 should be particularly careful. Further research is necessary and the possible side-effects should not be underestimated.
Seven plants with medicinal powers
Humans have been using medicinal plants for thousands of years. They even play an important role in modern medicine. Here are just a few that are still used to ward off illnesses and treat symptoms.
Image: picture alliance/blickwinkel/H. Duty
Bitter bark
Quinine is known for creating that bitter taste in tonic water but it is also on the World Health Organization's list of essential medicines. It's long been used to treat malaria - though it is no longer recommended as a first-line treatment by the WHO - and was first isolated from the bark of the cinchona tree in the early 1800s.
Image: picture alliance/blickwinkel/A. Jagel
Fragrant remedies
The bell-shaped flowers of the yellow cowslip (primula veris) are certainly charming. But this plant is more than just a pretty face. Native to most of Europe and western Asia, it is used as a herbal remedy against asthma and bronchitis.
Image: picture alliance/blickwinkel/H. Duty
Wake me up
Guarana, a climbing plant native to the Amazon basin is very common in Brazil where it is enjoyed as a drink. The plant's small red berries contain caffeine and have become a popular energy supplement. It's also used for stomach complaints.
Image: CC by A C Moraes
Miracle worker
The bark of the African cherry (Prunus africana) is something of a miracle worker. Traditional healers in Kenya use it to treat a host of ailments, including malaria, stomach pain and kidney problems. But it is most treasured for its use in prostate cancer treatments.
Image: DW/H. Fischer
Combating yawns
Ginseng is one of the most popular herbal remedies in the world and the plant's roots have long been used in Asia and North America to treat various complaints. Often taken as a tea, the Asian variety - which is considered to be more of a stimulant than its American counterpart - is used to boost the immune system and fight fatigue.
Image: CC-BY-SA-Lohrie
Jack of all trades
Vetiver is an extremely versatile grass. Native to India, it's been used to control erosion, in the production of essential oil, to make bags and mats, as an animal feed and in traditional medicine. The grass has antiseptic properties and is used in creams and soaps to treat acne and sores. Its anti-inflammatory properties have also seen it used in the treatment of gout and arthritis.
Image: picture-alliance/dpa/P.Goetgheluck
Dandelion improvements
The lowly dandelion is full of vitamins and minerals and it's often used as a diuretic to eliminate unwanted fluid in a person's body. Initial research also suggests it might improve digestion as well as gall bladder and liver function.
