While the term “genetic rescue” has been used in conservation for several decades, Revive & Restore uses an expansive definition that includes the use of advanced biotechnologies. With the increasing affordability of genomic sequencing and the advent of CRISPR-Cas9 gene editing technology there is an opportunity to develop a suite of innovative new genetic rescue applications. To that end, we are building a Genetic Rescue Toolkit that has the potential to advance and complement conventional conservation practice.
To describe the Genetic Rescue Toolkit and its cumulative potential, its tools—from genome sequencing to gene editing—are arranged from bottom to top in order of increasing complexity. The timeline for their application—from genomic insights to de-extinction—moves further out (x-axis) as complexity increases (y-axis). For further details, hover over the plus signs below.
DEVELOPING THE TOOLKIT
Any genetic rescue application, for any species, can benefit from two things: One, the sequencing of a high-quality reference genome of that species ; and two, the biobanking of a source of viable cells or tissue accessioned into a biorepository for future research. These essential resources can accelerate conservation efforts. Yet these basic, non-controversial, readily obtainable tools are still lacking for most wildlife species.
Other genetic rescue applications, that are more complex, require genetic engineering and gene editing tools. These tools could help facilitate adaptation for endangered species (see our Black Footed Ferret Project), control invasives, and bring species back from extinction (see our Woolly Mammoth Revival). While these applications are not without controversy and will require concerted effort to develop, we are in support of the development of all the tools in the toolkit and their effective, ethical use.
The diagram below displays just a small number of threatened and endangered species. A variety of threats drive each species toward extinction (in red) while a variety of corresponding genetic rescue applications lead them toward recovery (in green). The goal of genetic rescue is to move species to the left—away from extinction and closer to recovery.
To truly succeed, Genetic Rescue Toolkit applications must complement proven conservation approaches, such as habitat restoration and protection, resource management, invasive species control, captive breeding, adaptive conditioning, translocations, reintroductions, policy and advocacy, and ecological replacement. For details on each species and genetic rescue interventions roll over the plus signs.
Genetic Rescue Then and Now: The Florida Panther
Historically, genetic rescue has been a practice of helping animal populations suffering from low genetic diversity by introducing healthy individuals from unrelated populations. One famous success story is of the Florida panther. In 1995, fewer than 30 Florida panthers lived in the wild. Due to a severe population bottleneck and inbreeding depression, irregular (or “maladaptive”) physical traits evolved and fertility declined.
To increase genetic diversity and save the species from extinction, the US Fish and Wildlife Service translocated eight female Texas cougars into Florida to mate with the panthers (both are different names of the same species, Puma concolor). The resulting population grew quickly and fitness increased. There are now between 120 and 230 panthers living in the Florida range. The translocation was a success.
A Florida panther living in Everglades National Park. The photo was taken in 2016. (USFWS)
The increase in genetic diversity improved the resilience and adaptability of the Florida panther population. This remains at the heart of all genetic rescue approaches. And, today’s genomic technologies offer a broader suite of methods, more specific outcomes, and more precise insights.
In 2019, for example, researchers performed a genetic analysis of Florida panthers to evaluate if the present generation was still benefiting from the 1995 translocation. Using genome sequencing, the team found that the panthers had retained higher diversity than expected. The team was also able to calculate a proactive management plan for future translocations. Their genomic insights revealed that the Florida panther population’s health can be maintained with at least five translocations every 20 years, enabling precise long-term planning to prevent future declines.
From restoring genetic diversity to making de-extinction possible, our Catalyst Science Fund projects are helping to build the Genetic Rescue Toolkit. Currently these projects are solving for specific problems for single species. But with further research, these findings will be applied more broadly. Learn More About Our Catalyst Science Fund Projects >