Sunday March 24, 2019
Home Science & Technology Infertility g...

Infertility gene in mosquitoes to curb malaria

0
//

London: For the first time, researchers led by the Imperial College London, have genetically modified malarial mosquitoes so that they carry a gene that disrupts egg production in female mosquitoes.

They used a technology called “gene drive” to ensure the gene for infertility is passed down at an accelerated rate to offspring, spreading the gene through a population over time and raising the possibility of reducing the spread of disease.

Within a few years, the spread could drastically reduce or eliminate local populations of the malaria, carrying mosquito species.

The mosquito species Anopheles gambiae is a major carrier of malaria parasites in sub-Saharan Africa, where 90 per cent of annual malaria deaths occur.

Malaria infects over 200 million people each year and causes more than 430,000 deaths.

“Scientists have been trying to tackle malaria for more than 100 years. If successful, this technology has the potential to substantially reduce the transmission of malaria,” said study co-author professor Andrea Crisanti.

Normally, each gene variant has 50 per cent chance of being passed down from parents to their offspring.

In the team’s experiments with Anopheles gambiae, the gene for infertility was transmitted to more than 90 per cent of both male and female mosquitoes’ offspring.

The technique uses recessive genes so that many mosquitoes will inherit only one copy of the gene.

Two copies are needed to cause infertility, meaning that mosquitoes with only one copy are carriers, and can spread the gene through a population.

This is the first time the technique has been demonstrated in Anopheles gambiae.

The team targeted three different fertility genes and tested each for their suitability for affecting a mosquito population through gene drive, demonstrating the strength and flexibility of the technique to be applied to a range of genes.

“As with any new technology, it will be at least 10 more years before gene drive malaria mosquitoes could be a working intervention,” added professor Austin Burt from Imperial’s department of life sciences.

There are roughly 3,400 different species of mosquitoes worldwide.

“While Anopheles gambiae is an important carrier of malaria, it is only one of around 800 species of mosquito in Africa, so suppressing it in certain areas should not significantly impact the local ecosystem,” noted lead author Dr Tony Nolan.

The team aims to improve the expression of their gene drive elements. Exploring target genes is also helping the researchers to learn more about basic mosquito biology.

The results were published in the journal Nature Biotechnology.(ians)

(picture credit:upload.wikimedia.org)

Next Story

Novel Experimental Vaccine Offering Hope Against Malaria

A year later, the vaccinated non-human primates still had immunity against malaria, while eight control animals that were not vaccinated did not

0
Malaria, Vaccines
This new type of bed net can help prevent malaria: Lancet. (VOA)

An experimental new malaria vaccine is offering potentially long-lasting immunity against the persistent parasite that sickens hundreds of millions of people each year, a study suggests.

Most vaccines are designed to encourage the human body to respond to invading, disease-causing pathogens by creating antibodies that disable those pathogens.

However, the new vaccine takes a different approach by using a weakened form of a common herpes virus – cytomegalovirus, or CMV – that infects most people without causing the disease.

This new vaccine reduced the malaria-causing parasite’s release from the liver and into the blood of infected rhesus macaques by 75 to 80 per cent, reported the paper published in the journal PLOS ONE.

“The problem with most vaccines is that their effectiveness is often short-lived,” said lead author Klaus Fruh, professor at the Oregon Health and Science University in the US.

More people die of malaria than anything else in the world.
More people die of malaria than anything else in the world.

“Our cytomegalovirus-based vaccine platform can create and keep immunity for life. With further research and development, it could offer a lifetime of protection against malaria,” Fruh added.

Malaria is a serious and sometimes fatal disease caused by Plasmodium parasites, which are spread to humans through mosquito bites.

It can cause high fevers, shaking chills, flu-like illness and, in the worst cases, death.

Worldwide, 216 million people were infected with malaria in 2016, leading to 445,000 deaths.

Fruh and his team weaved tiny bits of their target pathogen into CMV, which is already being used in vaccines being developed to battle HIV and tuberculosis.

Those who receive the resulting, re-engineered CMV vaccine produce memory T-cells that can search for and destroy pathogen-infected cells.

A health service worker takes a blood sample for a malaria test in Dajabon, Dominican Republic, on the border with Haiti, Oct. 6, 2009. A test that doesn't require a needle or blood has won the Africa Prize for Engineering Innovation
A health service worker takes a blood sample for a malaria test in Dajabon, Dominican Republic, on the border with Haiti, Oct. 6, 2009. A test that doesn’t require a needle or blood has won the Africa Prize for Engineering Innovation, VOA

The team developed two different versions of their CMV-based malaria vaccine while using four different proteins made by the Plasmodium parasite.

The resulting vaccines delayed the parasite’s appearance in the blood of 16 infected and vaccinated rhesus macaques by eliminating between 75 and 80 per cent of parasites from the liver.

Also Read- Deficiency of Zinc May up Hypertension

A year later, the vaccinated non-human primates still had immunity against malaria, while eight control animals that were not vaccinated did not.

The CMV vaccine platform has been licensed by San Francisco-based Vir Biotechnology, which plans to lead a human clinical trial for a CMV-based HIV vaccine in 2019.  (IANS)