Gene-editing is Science mag's breakthrough of 2015

US researchers tweaked malaria-carrying mosquitos, opening the door to eradication of the disease.
US researchers tweaked malaria-carrying mosquitos, opening the door to eradication of the disease.PHOTO: AFP

MIAMI (AFP) - A gene-editing technique known as Crispr was named on Thursday by the influential US journal Science as 2015's breakthrough of the year, due to its potential to revolutionise health and medicine.

The method has stirred controversy, particularly after Chinese researchers earlier this year announced they had deliberately edited the DNA of nonviable human embryos from a fertility clinic.

Concerns over such research - and the prospect of altering humans to promote certain, desirable traits - recently prompted global scientists to urge researchers to steer clear of interfering with embryos destined for pregnancy, citing the risks of introducing permanent changes into the population.

But many are excited about the "superior ability of Crispr to deliver a gene to the right spot compared to its genome editing competitors - as well as the technique's low cost and ease of use," said the journal Science.

"Clinical researchers are already applying it to create tissue-based treatments for cancer and other diseases," wrote managing news editor John Travis.

"Crispr may also revive the moribund concept of transplanting animal organs into people."

Thousands of labs, high school students and scientists have already begun exploiting the three-year old technique, he said.

"It's only slightly hyperbolic to say that if scientists can dream of a genetic manipulation, Crispr can now make it happen," said Travis.

US researchers have carried out genetic tweaks to malaria-carrying mosquitos so their offspring feature genes that block the parasite which causes the disease, opening the way to eradicating it.

Previous studies in recent years had already shown it was possible to modify mosquitos genetically so they neutralise the parasite called Plasmodium falciparum, which causes malaria.

A new study, published Nov 24, 2015 in Proceedings of the National Academy of Sciences, marked a Crispr advance. It involved inserting parasite-blocking genes in the DNA of Anopheles stephensi mosquitos, which are a leading vector of malaria in Asia, to ensure that these genes are passed on to the bugs' offspring.

Researchers said they had achieved a rate of transmission of 99.5 per cent.

The Crispr technique, first announced in 2012, experienced a "massive growth spurt last year," Travis said, describing it as a "molecular marvel."

Marcia McNutt, editor-in-chief of the Science family of journals, said in an accompanying editorial that "in two years' time Crispr will have brought to many diverse fields in biology the enduring level of excitement and optimism that immunotherapy has brought to cancer patients."

Immunotherapy, a host of techniques which harness the body's immune cells to fight cancer, was named Science's breakthrough of 2013.

But the lay public was less enthusiastic about Crispr, according to online visitors who voted on the top 10 picks of the year on Science's website.

To 35 per cent of voters, the flyby of Pluto by an unmanned Nasa probe called New Horizons was the top breakthrough of the year, offering views in unprecedented detail of the distant dwarf planet.

Crispr followed with 20 per cent of online votes.