In Mosquitoes, a study attempts to demonstrate provisorial self-deleting transgenes

In Mosquitoes, a study attempts to demonstrate provisorial self-deleting transgenes ...

A&M AgriLife Researchscientists have tested a technology to produce temporary genetic modifications in mosquitoes. These changes have been eliminated in the long run.

Scientists in the field of genetic change might need to modify mosquitoes in order to help manage populations and prevent vector-borne diseases like the West Nile virus without permanently altering wild populations'' genetic makeup.

A study containing their tests and engineering a self-eliminating transgene in the yellow fever mosquito, Aedes aegypti, was published in the National Academy of Sciences PNAS Nexus. The authors,Zach Adelman, Ph.D., and Kevin Myles, both professors from the Texas A&MCollege of Agriculture and Life Sciences Department, describe a technique for removing edited genes within mosquito populations.

The methodology is a first step toward establishing safeguards for gene modifications to control mosquitoes and the vector-borne diseases they carry. Adelman said the aim is to examine the proposed changes without making them permanent and without the danger of spreading them to wild populations.

When you are utilizing technology, you do not want to get into a situation where you have to tell a regulatory authority or the public that if something bad happened, were just out of luck, Adelman said. This is how we get back to normal if the experiment does or does not come out the way we expect.

Adelman and Myles are co-directing a team of researchers who received a five-year $3.9 million grant from the National Institute of Allergy and Infectious Diseases to test and refine the self-eliminating transgene technology.

Back to normal in a few generations

Adrenalman believes that approaches based on genetic control of insect populations are being developed to prevent mosquito-transmitted diseases. Nevertheless, many of these approaches are based on highly invasive, self-propagating transgenes that can rapidly spread the trait into other populations of mosquitoes.

Aedes aegypti mosquitoes are known vectors of diseases, thanks to Keun Chae, a post-doctoral researcher. Chae erupted a duplicated genetic code region along with two genes for fluorescent proteins into the middle of a gene for eye pigment.

The result was a white-eyed mosquito, with red and green fluorescence in the eyes and body. They acted as a precise set of molecular scissors that could break the transgene sequences. Over several generations, mosquitoes regained their normal eye pigment and lost the altered genes.

Adelman said the work is a proof of the principle that scientists can do two essential things, including remove transgenes placed in mosquitoes and repair damaged genes.

Adelman said the group is developing genetic therapies for controlling mosquito populations. Our approach provides a braking system that may restore sequences in the wild.

Genetic research might benefit from self-editing transgenes.

Myles said developing this self-editing transgene is the first step in a long process. The mosquito genome is difficult to manipulate, and the breakthrough is the culmination of over six years of experiment.

He said the first publication on genetic modification in wild populations begins to address concerns about genetic modification. Adelman and Myles believe this technology will allow researchers to evaluate the effects of changes more cautiously within the environment and on other animals than mosquitoes.

These are well-maintained genetic pathways, and there is no reason to believe this method might be applied to a wide spectrum of organisms, according to Myles.

Both scientists are looking forward to expanding the use of their findings in the context of a highly active gene drive. They hope that their technique will be beneficial for geneticists and in pushing the boundaries of genetic research.

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