Rescuing a Florida cat, with a Texas twist

A diverse ancestry is a powerful antidote against extinction. As life in the wild is inevitably plagued with surprises such as food shortages, extreme temperatures and disease outbreaks, animals with an assorted genetic makeup can conveniently deploy the characteristics they need to survive these events. Animals that lack such versatility, however, are less equipped to survive hardships. By the 1990s, habitat loss and limited mating options had reduced the Florida panther population to fewer than 30 animals, many suffering from hereditary diseases. These cats (Puma concolor coryi) are a smaller subspecies of the puma (Puma concolor) and can only be found in Florida, USA. To bring Florida panthers back from the brink of inbreeding and extinction, conservation scientists introduced eight female pumas from Texas to the Florida cats in 1995, hoping to bring healthier genes into the declining Florida population. Thanks to these efforts, about 200 panthers may now inhabit the region. But did the conservation strategy introduce genetic diversity into the Florida population or threaten the key features that distinguish these Florida natives? Diana Aguilar-Gomez from University of California, Los Angeles, USA, and colleagues from multiple institutions in the USA and Hong Kong investigated the lasting genetic impact of bringing Texas pumas into the Florida panther family.The team extracted DNA samples from 29 Florida panthers, most of which had sadly died in accidents on the roads, analyzing the cats’ genetics. They also dug into older DNA records: samples from Florida panthers before 1995, from pumas from other parts of the Americas and from the five Texas females that had kittens with Florida males, to find out more about their genes. The researchers wondered whether the Florida panthers were now free of harmful mutations, which showed previously in the Florida population as problems such as twisted tails and infertility. Using genetic analysis, the scientists learned that, even though many mutations remain in the Florida population, having a more blended genetic background leads to healthier cats. Briefly, for every gene, each kitten gets one copy from each parent. Usually, organisms use the healthiest version, lowering the chance of health problems, even if they carry a faulty copy of the gene. Effectively, mixed cats have a richer toolbox to handle challenging environments.Next, the scientists used computer simulations looking for the genetic signatures that are unique to each population to ask whether the Florida and Texas puma populations remain genetically distinct from each other, and to predict the future of the Florida panthers in different scenarios – a kind of scientific forecasting that combines math and biology. The researchers found that, by looking at the DNA of the Floridian cats, it was still possible to tell the Floridians apart from the Texan pumas, similar to how ancestry kits can pinpoint our ethnic backgrounds. This finding suggests that introducing individuals with a healthier background did not erase the vulnerable population. Interestingly, the scientists’ model predicts that, though the outsiders likely saved Florida panthers from extinction, Texas ancestry may be declining in Florida panthers. The reason for this trend remains unclear, but the team speculates that Florida's environment may be favoring certain genes, gradually leading to the loss of those better suited for a Texas habitat.While not completely out of the woods (definitely, no pun intended), there is reason for optimism. These Florida panthers are no longer limited to having babies with their close relatives, and kittens with birth defects are rarer. As for identity concerns, the panthers seem unbothered – after all, their DNA still reveals their Florida roots. So yes, the Sunshine State remains the home of alligators, black bears and, of course, the charming panthers with just a hint of Texan flavor.