New insect model may help eradicate disease that sickens millions annually
Using a groundbreaking gene editing technique, University of California scientists have created a strain of mosquitoes capable of rapidly introducing malaria-blocking genes into a mosquito population through its progeny, ultimately eliminating the insects’ ability to transmit the disease to humans.
This new model represents a notable advance in the effort to establish an antimalarial mosquito population, which with further development could help eradicate a disease that sickens millions worldwide each year.
To create this breed, researchers at the Irvine and San Diego campuses inserted a DNA element into the germ line of Anopheles stephensi mosquitoes that resulted in the gene preventing malaria transmission being passed on to an astonishing 99.5 percent of offspring. A. stephensi is a leading malaria vector in Asia.
The study underlines the growing utility of the Crispr method, a powerful gene editing tool that allows access to a cell’s nucleus to snip DNA to either replace mutated genes or insert new ones. Results appear this week in the early online edition of Proceedings of the National Academy of Sciences.
“This opens up the real promise that this technique can be adapted for eliminating malaria,” said Anthony James, Distinguished Professor of molecular biology & biochemistry and microbiology & molecular genetics at UCI.
For nearly 20 years, the James lab has focused on engineering anti-disease mosquitoes. His anti-dengue fever models have been tested in cage trials in Mexico, and in 2012, he helped show that antibodies that impair the parasite’s biology adapted from the immune systems of mice can be introduced into mosquitoes. This trait, though, could only be inherited by about half of the progeny.
Earlier this year, UC San Diego biologists Ethan Bier and Valentino Gantz working with fruit flies announced the development of a new method for generating mutations in both copies of a gene. This mutagenic chain reaction involved using the Crispr-associated Cas9 nuclease enzyme and allowed for transmission of mutations through the germ line with an inheritance rate of 95 percent.
The two groups collaborated to fuse Bier and Gantz’s method with James’ mosquitoes. Gantz packaged antimalaria genes with a Cas9 enzyme (which can cut DNA) and a guide RNA to create a genetic “cassette” that, when injected into a mosquito embryo, targeted a highly specific spot on the germ line DNA to insert the antimalaria antibody genes.
To ensure that the element carrying the malaria-blocking antibodies had reached the desired DNA site, the researchers included in the cassette a protein that gave the progeny red fluorescence in the eyes. Almost 100 percent of offspring – 99.5 percent, to be exact – exhibited this trait, which James said is an amazing result for such a system that can change inheritable traits.
He added that further testing will be needed to confirm the efficacy of the antibodies and that this could eventually lead to field studies. “This is a significant first step,” said James, a National Academy of Sciences member. “We know the gene works. The mosquitoes we created are not the final brand, but we know this technology allows us to efficiently create large populations.”
Bier, a professor of biology at UC San Diego, also noted that “the ability of this system to carry large genetic payloads should have broad applications to the future use of related Crispr-based ‘active genetic’ systems.”
Malaria is one of the world’s leading health problems. More than 40 percent of the world’s population live in areas where there is a risk of contracting the disease. According to the Centers for Disease Control & Prevention, 300 million to 500 million cases of malaria occur each year, and nearly 1 million people die of the disease annually – largely infants, young children and pregnant women, most of them in Africa.
Nijole Jasinskiene, Olga Tatarenkova, Aniko Fazekas and Vanessa Macias of UCI contributed to the study, which was supported by grants from the National Institutes of Health (AI070654, NS029870, AI29746 and AI116433) and the W.M. Keck Foundation and a gift from Drs. Sarah Sandell and Michael Marshall (to Bier).
About the University of California, Irvine: Currently celebrating its 50th anniversary, UCI is the youngest member of the prestigious Association of American Universities. The campus has produced three Nobel laureates and is known for its academic achievement, premier research, innovation and anteater mascot. Led by Chancellor Howard Gillman, UCI has more than 30,000 students and offers 192 degree programs. It’s located in one of the world’s safest and most economically vibrant communities and is Orange County’s second-largest employer, contributing $4.8 billion annually to the local economy. For more on UCI, visit www.uci.edu.
Media access: Radio programs/stations may, for a fee, use an on-campus ISDN line to interview UC Irvine faculty and experts, subject to availability and university approval. For more UC Irvine news, visit news.uci.edu. Additional resources for journalists may be found at www.communications.uci.edu/for-journalists.
Director of Research Communications
Tom Vasich | EurekAlert!
TSRI researchers develop new method to 'fingerprint' HIV
29.03.2017 | Scripps Research Institute
Periodic ventilation keeps more pollen out than tilted-open windows
29.03.2017 | Technische Universität München
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
29.03.2017 | Materials Sciences
29.03.2017 | Physics and Astronomy
29.03.2017 | Earth Sciences