Myotis bats roost together. Credit: Dr. Nicole Foley/Texas A&M University College of Veterinary Medicine and Biomedical Sciences
Researchers at Texas A&M University say the development of viral tolerance in meotis bats may help scientists prevent future pandemics.
Bats carry some of the most deadly zoonotic diseases that can infect humans and animals, such as Ebola Covid-19.
In an article recently published in the magazine Cellular genomicsA research team at Texas A&M University revealed that some… Classify Bats are protected against the viruses they carry because they usually exchange immune genes during seasonal mating flocks.
“Understanding how bats evolved the ability to tolerate the virus may help us learn how humans can better combat emerging diseases,” said Dr. Nicole Foley, from the Texas A&M College of Veterinary Medicine and Biomedical Sciences (VMBS). “As genomic scientists, our work often lays the foundation for the research conducted by the scientists we study virus Transmission directly. They may develop vaccines for diseases or monitor vulnerable animal populations. We all depend on each other to survive the next pandemic.
Muscular bat, hunting. Credit: Dr. Nicole Foley/Texas A&M College of Veterinary Medicine and Biomedical Sciences
Because bats are often immune to the diseases they carry, Foley and Dr. Bill Murphy, a professor in the Department of Veterinary Integrative Biosciences at VMBS, believe studying bats' immunity to disease could hold the key to preventing the next global pandemic.
“Due to the COVID-19 pandemic, outbreak prediction and prevention are at the forefront of concerns for researchers and the public alike,” Foley said. “Many bat species carry viruses that are harmful to human health, which means they become reservoirs of disease – they carry viruses, but more importantly, they do not show symptoms.”
Long-eared muscular bat. Credit: Dr. Nicole Foley/Texas A&M University College of Veterinary Medicine and Biomedical Sciences
The secret of swarming behavior
To uncover exactly how bats' ability to withstand these deadly viruses evolved, Foley, Murphy and their international research partners mapped the evolutionary tree of meotis bats, something they knew was crucial in trying to identify genes that might be involved.
“Meotis bats are the second largest genus of mammals, with more than 140 species,” she said. “They are found in almost all parts of the world and host a large variety of viruses.”
To add to the difficulties associated with knowing species relationships, Myotis and other bat species also engage in swarming behavior during mating.
Myotis bats roost together. Credit: Dr. Nicole Foley/Texas A&M University College of Veterinary Medicine and Biomedical Sciences
“You can think of swarming behavior like a social gathering; there's a lot of flight activity, increased communication, and mingling between species; for bats, it's no different than going to a club,” Foley said.
Complicating matters further for researchers, swarming is creating increasing numbers of hybrid bats — individual bats with parents from different species.
“The problem with meotis bats is that there are so many species, about 130 species, but they all look very similar,” Foley said. “It can be very difficult to tell them apart from each other, so hybridization makes it even more difficult. If we're trying to map how these bats evolved so we can understand their immunity to diseases, then being able to know which is which is very important.”
Long-eared muscular bat. Credit: Dr. Nicole Foley/Texas A&M University College of Veterinary Medicine and Biomedical Sciences
Deconvolution
With this in mind, and to create a map of the true relationships between meotis bats, Foley and Murphy first decoded the genetic code of hybridization so they could figure out the species more clearly.
“We collaborated with researchers from Ireland, France and Switzerland to sequence the genomes of 60 species of meotis bats,” she explained. “This allowed us to know which parts of DNA Represents the true evolutionary history of species and parts that arose from hybridization.
With this part of the puzzle solved, researchers were finally able to examine the genetic code more closely to see how it could shed light on disease immunity.
They found that immune genes were among the most frequently exchanged genes between species during swarming.
“Swarming behavior has always been a mystery to researchers,” Foley said. “Now we have a better understanding of why this particular behavior evolved — perhaps to promote hybridization, which helps spread beneficial immune gene variants more widely throughout the population.”
Drs. Nicole Foley and William Murphy. Credit: Texas A&M University College of Veterinary Medicine and Biomedical Sciences
New questions for researchers
Foley and Murphy's findings have opened the doors to new questions about the importance of hybridization in evolution.
“Hybridization played a much larger role in our findings than we expected,” Foley noted. “These findings led us to question the extent to which hybridization has obscured genomicists' knowledge of mammalian evolutionary history to date.
“Now, we hope to identify other instances where hybridization has occurred between mammals and see what we can learn about how they are related and even how and why genomes are organized this way,” she said.
Reference: “The effect of nuclear stasis and swarming on the evolution of viral tolerance in a species-rich radiation of bats” by Nicole M. Foley, and Andrew J. Harris, and Kevin R. Bredemeyer, Manuel Rudy, and Sebastian J. Michael F. Criscitiello and William J. Murphy, January 17, 2024, Cellular genomics.
doi: 10.1016/j.xgen.2023.100482
