Gene editing technology could be used to save species on the brink of extinction

The biodiversity of the earth is in crisis. A “sixth mass extinction” threatens the beloved and important fauna. It also threatens to reduce the amount of genetic diversity – or variation – in species.

This variation in genes within a species is crucial for their ability to adapt to changes in the environment or resist disease. The genetic variation is therefore crucial for the long -term survival of species.

Traditional conservation efforts, such as protected areas, measures to prevent poaching and captive reproduction – are essential to prevent extinction. But even when these measures manage to increase the number of populations, they cannot recover the genetic diversity that has already been lost. The loss of a single gene variant can take thousands of years of evolution before being recovered by a lucky mutation.

In a new article in nature, review biodiversity, an international team of geneticist and wildlife biologists maintains that the survival of certain species will depend on genetic publishing, as well as more traditional conservation actions. The use of these advanced genetic tools, such as those who are already revolutionizing agriculture and medicine, can give a boost to endangered species by adding a genetic diversity that is not there.

Genetic genius is not new. Plant farmers have used it for decades to develop crops with features to stimulate resistance to diseases and drought tolerance. About 13.5% of the world’s arable land cultivate genetically modified crops. Genetic editing tools such as CRISPR are also used in “de-extinction” projects which aim to recreate extinct animals.

The Colossal Laboratory & BioSciences company based in Dallas has attracted the headlines for its efforts to bring back the woolly mammoth, the dodo and the wolf desire. In the de-extinction, the DNA of a living relative species is published (modified) to approximate the most charismatic features of the extinguished species.

For example, to “resuscitate” a woolly mammoth, colossal researchers plan to spit mammoth genes (recovered from ancient vestiges) in the genome of the Asian elephant to produce an elephant hybrid and hairy and durable mammoth. Colossal recently designed gray wolf puppies with 20 DNA gene modifications to say wolf off.

The “Jurassic Park” style revival of longtime creatures has drawn considerable attention and funding, which accelerated the development of genome engineering techniques. These same genome editing tools can be used for the conservation of existing and threatened species. If we can edit a mouse to have gigantic hair, or modify a wolf to look like a terrible wolf, why not modify the genome of an endangered bird to make it more resilient to diseases and climate change?

Museum specimens

Using DNA from historical samples, scientists can identify significant genetic variants that a species has lost. Many museums hold skins, bones or centenary seeds – a genomic time capsule of past diversity. With the edition of the genome, it is possible to reintroduce these lost variants in the pool of wild genes.

In restoring genetic variation, species can be strengthened against emerging diseases and environmental change. A sharp drop in the number of populations is called “strangulation bottleneck”. During a bottleneck, consanguinity and genetic drift lead to the random loss of genetic diversity. Harmful mutations can also increase frequency. Such “genomic erosion” compromises the health of individuals and can make populations more prone to extinction.

If we can identify a particularly harmful mutation that has spread in the population or a variant that has been lost, we could replace it in a few individuals using genes. Helped by a natural selection, the healthy variant was gradually spread through the population.

If a threatened species lacks genes which he desperately needs to survive new conditions, why not borrow them from a close relative who already has these features? Known as the facilitated adaptation, it could help fauna to deal with threats such as climate change.

In agriculture, these transfers of inter-species are routine. The tomatoes were designed with a mustard vegetable gene to tolerate cold, and the chestnut trees obtained a wheat gene for disease resistance. There is no reason why such techniques cannot be extended to animals.

These genetic interventions can complement, but never replace traditional conservation measures. Habitat protection, control of invasive predators, captive reproduction programs and other actions in the field remain absolutely necessary. Above all, the genes edition only makes sense if the target population has recovered sufficiently in number (often by conservation), to allow natural selection to do its job.

Measure the risk of extinction

The animals or plants published in genes would have no chance if it was released in a sterile habitat or a poaching hotspot. Genomic tools can give an additional advantage to species that are already saved from immediate threats, equipping them for adaptive evolution in the future.

Climatic areas are changing, new diseases spread and populations once isolated are cut in small fragments of habitat. Without intervention, even intensive habitat management may not prevent a wave of extinctions.

However, a gene editing strategy also includes significant risks and unknowns. A technical concern is the off -target effects – the CRISPR and other genetic publishing techniques could make involuntary DNA changes in addition to the planned editing. In other words, you try to insert a resistance gene, but accidentally disrupts another gene in the process. Likewise, a gene can have more than one function, called pleiotropia.

Especially in the species studied less well, we may not be aware of all these pleaotropic functions or effects. Regulatory inertia and public skepticism can also present large obstacles – these questions have historically limited the deployment of genetically modified organizations (GM), in particular in agriculture.

There are also evolutionary and ecological uncertainties. A montage of deliberate genes could have training effects on how the species evolves over time. For example, if an individual receives a very beneficial gene that spreads quickly, he could replace all the other variants of genes at this location in the genome (the complete DNA complement in the body cell). This is known as a “selective scanning”, and inadvertently reduces genetic diversity in this region of the genome.

Some criticisms argue that the account of a rapid genetic solution could distract deep causes of the loss of biodiversity. If people believe that we can simply “edit” a species to save it, will it know the urgency to protect habitats or reduce carbon emissions? Disappointing extinction as reversible could sow false hope and reduce the motivation for difficult environmental action.

Conservation efforts, solid environmental policies and legal protections remain essential. The same goes for the restoration of the habitat, the climate action and the reduction of the impact on the environment by humans.

However, Genome Engineering is a new tool in the conservation toolbox. It is the one who gave the right assistance and environmental encouragement – can help save the species of extinction.

This article is republished from the conversation under a Creative Commons license. Read the original article.