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gene drive makes it possible to quickly change traits of different species. Now they are looking for a way to control the process

New technologies in the field of genetic engineering today allow us to change the properties of different species quickly and with great flexibility, for example controlling the reproductive capacity of pests, but are they safe?

New technologies in the field of genetic engineering allow us today to change the properties of different species very quickly and flexibly. One of the most significant applications of these technologies may be the genetic modification of entire species in nature - especially species that cause heavy damage, such as mosquitoes that transmit diseases such as malaria or invasive species that harm the environment and the economy. Changing the characteristics of these species will allow a significant reduction of the harmful populations, and perhaps even lead to their complete eradication. However, one of the main concerns from using this technology is that the genetically modified genes will "slide" from the harmful population to other populations, and even to other species, causing severe and unexpected ecological changes.

Dr. Gili Greenbaum. Photo: The Hebrew University
Dr. Gili Greenbaum. Photo: The Hebrew University

Dr. Gilly Greenbaum from the Institute of Life Sciences at the Hebrew University and three leading researchers from Stanford University in the USA, published New research on the subject in the journal Plos Genetics. This is a theoretical study based on computational models, and presents the possibilities facing the world of science for the use of gene drive technology, which provides first A solution to the problem of the distribution of transgenic genes in natural populations.

gene drive produces a "genetic engine" that violates the laws of natural inheritance, thus enabling the widespread and rapid distribution of transgenic genes in the population, even in situations where natural selection is strong against them. In fact, this genetic engine makes it possible to bring defective transgenic genes to widespread distribution within a few generations. Because this technology is based on inheritance through sexual reproduction, it is applicable in insects, mammals, reptiles, fish and most plants, but not in bacteria and viruses.

Despite the great efficiency of the method and the success of experiments in the laboratory, the gene drive technology has not yet left the laboratory for the field due to the fear of the set of risks involved in the use of extensive genetic engineering outside the laboratory, among them the overflow of the engineered genes from the target population to other populations or even to other species. Gene overflows may have unexpected effects, including the extinction of populations and species that we do not want to harm, and as a result even lead to devastating effects on entire ecosystems.

In order to understand the spread of gene drive engines between populations and the conditions necessary for their gliding, the researchers created a model of two populations, in one of which a gene drive engine is activated. The researchers modeled the evolutionary dynamics that would take place, and tracked the spread of the engineered genes in both populations over time. As a result of their work they discovered The researchers a space of possibilities in which the genetic features of thegene drive which prevents gene overflow beyond the target population. The principle that prevents gene overflow is called by the researchers differential targeting, and it is based on the balance created between different evolutionary and ecological forces. However, the researchers found that the principle is applicable only when the transition rates between the populations are relatively low, and when the rates are high, a very precise planning of the gene drive is necessary. Therefore, the researchers suggested that it is not possible to use the principle of differential targeting when the connectivity between the populations is high, because in this situation a very precise design of the gene drive engine would be necessary - a precision that is not possible with the existing technology.

Dr. Gili Greenbaum concludes that "we find that the use of gene drive technology is possible, but requires the planning of the genetic parameters in a precise manner in order to avoid dangerous spillover to other populations, which may be an obstacle in the implementation of the idea. On the one hand, using genetic engineering on entire populations can lead to success in the fight to eradicate terrible diseases such as malaria and Zika, which are transmitted by mosquitoes, and prevent the damage caused by invasive species around the world. On the other hand, the study turns on a warning light that says that the problem of surfing is likely to be significant and difficult to solve. Genetic engineering of species without consequences? We are still far from there. In future research, we would like to examine the effect of various ecological and evolutionary elements on the process of the spread of gene drive engines, in order to better understand how they will behave in field conditions."

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