Detection of artificial transgenes, new CSI-like approach for tracking genetically modified animals

The fake transgenes that genetically modified animals leave behind in the environment have been identified by McGill University researchers as a new means to track them. The discovery gives researchers a strong new tool for tracking down and managing genetically modified animals that have gotten out or been released into the wild.

The magic of eDNA

The researchers reveal for the first time in a paper published in PLOS ONE that artificial transgenes from a range of genetically modified species such as fruit flies, mice, and tetra fish can be discovered and sequenced from DNA left behind in soil, water, feces, urine, and saliva. These discoveries could be utilized to detect the transgenes of genetically modified mosquitos in pools of standing water in newly released areas, for example.

Environmental DNA (eDNA) has proven to be more accurate and effective than standard animal monitoring approaches, requiring less time and cost.

"Until now, no one has applied these environmental DNA approaches to genetically modified animals in the wild," explains Charles Xu, a PhD student at McGill University's Department of Biology. "Animal transgene detection from eDNA can be very valuable since it can tell you whether genetically modified animals are there without having to look for them."

An explosion of genetically modified animals

Advances in genome-editing technologies such as CRISPR have sped up the process of making genetically modified species, resulting in a surge in the quantity and types of genetically modified animals produced around the world. They bring with them questions about the new animals' ecological, evolutionary, and bioethical consequences. Some genetically modified animals can be purchased by the general public, such as fluorescent aquarium fish, while others, such as mosquitos, have been released into the wild. Artificial transgenes, or genes that have been altered by scientists or artificially introduced from another species, are carried by the organisms.

"Because genetically modified animals can often be mistaken for their wild counterparts based on looks alone," he continues, "environmental DNA or eDNA technologies could be very valuable for early detection and monitoring purposes." "This is especially true in circumstances where these creatures escape from the lab or the farm, migrate to places where they don't belong, or crossbreed with wild species."

In the future, labs, companies, and governments involved in the production and management of genetically modified animals will be able to recognize and track them in real-world situations using eDNA approaches.