Florida panthers carry Texas puma genes for better and maybe worse, UCF profs learn
A desperate rescue decades ago of Florida panthers may have included a deal with a DNA devil, which may or may not bring a bad outcome but should be watched closely, as scientists from the University of Central Florida have begun to learn.
By the 1990s, the state’s panthers numbered in the dozens and suffered from physical maladies of inbreeding. Wildlife authorities brought in eight Texas pumas, setting them free in Southwest Florida, hoping they would deepen the wild cats’ gene pool.
By many accounts, it worked well. The population of Florida panthers rebounded to more than 200, and the animals became generally healthier, though still losing precious habitat to development, getting run over by cars at a high rate and today suffering a mysterious affliction of leg weaknesses labeled feline leukomyelopathy.
However, as scientists are cautioning now, the genetic infusion from Texas has left the Florida animals with harmful mutations.
Their deep dive into existing and massive genetic data sets began during the pandemic’s lockdowns, giving them opportunity to tease out clues, including from a little-known episode: in the 1950s and 60s, Central American pumas were released in South Florida, also adding harmful mutations to Florida panther genetics.
“Although there’s still no evidence of these mutations emerging at the phenotypic level, we want to monitor the genetic health of the Florida panther because things could also go south pretty quickly, especially if their population remains small,” said Alexander Ochoa, a postdoctoral scholar in UCF’s biology department.
Phenotypic means evident troubles, like when inbred panthers back in the 1980s and 90s had heart failure, undescended testicles and pathogenic diseases.
Ochoa conceived of the research and was joined by UCF biology professor Robert Fitak in co-writing the research article “Give and Take: Effects of Genetic Admixture on Mutation Load in Endangered Florida Panthers” that appeared in the Journal of Heredity this month.
Fitak hired Ochoa to come to UCF three years ago, with the two having met early in their specialized careers of wildlife genetics at the University of Arizona.
The two were helped in the research by other seasoned scientists: Dave Onorato with the Florida Fish and Wildlife Conservation Commission Fish and Wildlife Research Institute and a state leader in panther recovery; Melanie Culver with the University of Arizona, whose doctoral dissertation was in puma genetics; and Melody Roelke-Parker of the Frederick National Laboratory for Cancer Research, who previously was a Florida wildlife veterinarian focused on panthers.
In 2019, while Ohio State University, Ochoa published research that relied on advanced computer analysis to find that the introduction of Texas cats vastly expanded the genetic diversity of Florida panthers
“This tells us a lot about the genetic underpinnings of this iconic conservation success story,” Ochoa said, commenting then for a university announcement. “The genetic diversity we found was much greater than some scientists previously thought, and likely contributed to the recovery of Florida panthers after the introduction of the Texas pumas.”
“In the mid-1990s, about 21 percent of Florida panthers had a heart problem called atrial septal defect, and more than 60 percent of the males had undescended testicles, a serious threat to the survival of the population,” the university announcement added. “In recent years, those numbers have dropped to 7 percent and 3 percent respectively.”
His next study, Ochoa said then, would clarify what harmful genetics came from Texas cats.
The fruits of that study were announced Monday by the University of Central Florida.
“I was expecting that the genetic rescue program was in general beneficial to Florida panthers,” Ochoa said. “But at the same time one of the unexpected findings was that a reasonable amount of novel harmful mutations from different source populations were also introduced into the Florida panther population.”
Fitak said the analysis that ferreted out harmful mutations doesn’t identify specific disorders that may result. But, with the population of panthers still so small, panthers with those mutations could mate and boost the chances of disorders emerging.
“We know that the genetic mixing has overall been a success for Florida panthers, but we need to be aware of any deleterious genetic stowaways that are tagging along for the ride,” Fitak said.
