Understanding gene flow and its implications for gene drive research

Gene flow is the transfer of genetic information from one population to another. Also known as gene transfer or gene migration, it plays a crucial role in the evolution and adaptation of species.

Understanding the dynamics of gene flow is essential to assess the potential risks and benefits of gene drive approaches. Gene drive technology works by promoting the inheritance of a selected genetic trait within a population, leading to this trait becoming increasingly common within a specific species over time. Researchers have been studying how to harness this technology to address global challenges, including to control the transmission of vector-borne diseases and populations of invasive alien species which threaten sensitive ecosystems.

Photograph: Cells under microscope.

Gene flow occurs naturally in the environment through two main dynamics:

• Vertical gene flow happens through mating, transferring genetic traits from one generation to another within a species or between closely related species. It is a natural part of evolutionary processes and plays a significant role in how traits are inherited.
• Horizontal gene flow involves the transfer of genes through non-sexual routes to unrelated organisms. While more common in bacteria, this type of gene flow is much less frequent in complex organisms.

The potential implications of gene flow for gene drive research vary depending on specific circumstances. For example, gene drives could spread beneficial traits to malaria-carrying mosquitoes to help combat the disease. However, researchers must also consider whether the genetic modification could be passed on beyond its target population and, if so, whether it could lead to unintended impacts.

Current studies indicate that gene flow between targeted and non-target species is generally unlikely due to genetic and ecological barriers. Despite this low probability, researchers continue to explore and refine gene drive technologies, notably by developing systems with built-in safeguards. These strategies aim to control how far and fast gene drives can spread by designing systems that only activate under specific conditions or within certain populations, or are self-limiting through time.

Understanding these interactions and their risks and benefits is an integral part of gene drive research. Learn more about gene flow and its implications for gene drive research in our factsheet: What is Gene Flow?