In the latest episode of Genetics Unzipped, the team take to the night skies with a closer look at the genetics of bats. Usually the stuff of horror films and Halloween, these fascinating mammals have many important genetic secrets to share with us about evolution, longevity, immunity and more.
Reporter Georgia Mills speaks with one of the world’s leading bat geneticists, Professor Emma Teeling from University College Dublin. She’s Director of the Centre for Irish Bat Research and co-founding Director of Bat1K, a global consortium sequencing the genomes of every single one of the world’s living bat species. So, what makes bats so special?
“Bats are probably the most extraordinary of all mammals,” Emma explains. “If you think about it, they’re the only mammals that have achieved true self powered flight. Anything else just falls with style, but bats can fly. One in five of every living mammal on this planet today is a bat and there’s about 1,400 different species. They’re found throughout the entire world, missing only from the extreme polar regions. And also bats can use extraordinary sensory perception, and are able to orient in complete darkness by using sound alone.”
Recently published in the journal Nature, the first findings from the Bat1K project have shed light on how bats evolved. The results have also brought insights into their unusual longevity, metabolism and immune systems, helping to explain why bats can cope with infections that make other animals, including humans, seriously ill.
The evolution of echolocation
Although this ability to sense the world through sound is not unique to bats – and not all bats can echolocate – they have certainly taken it to another level. So, how did this ability evolve?
As Dr Kaline Davies from Queen Mary university of London explains to Georgia, “We can hypothesise that either it’s evolved once in all bats and was then lost in the non-echolocating fruit bats, or otherwise it’s evolved multiple times, at least twice in different groups of bats, but we’re still not really clear.
I think it’s likely that echolocation probably did evolve multiple times, so maybe there was some kind of increased hearing capability in the ancestor of bats and then later on in different lineages that was further developed to create the more advanced echolocation that we see in some extant species.”
Bats and coronaviruses
While bats don’t deserve the reputation they get from horror movies, they are carriers of many diseases. And while they don’t necessarily get sick, they can act as reservoirs for infectious agents and can pass them on to humans and other animals. This includes coronaviruses, of which the most famous is SARS-CoV-2, the virus that causes COVID-19.
It’s still not clear whether bats played any role in the current pandemic. But to discover more about how these animals pick up and transmit infections, Georgia spoke with Elizabeth Castro-Salas at the Instituto Politécnico Nacional in Mexico City, who is studying coronaviruses in Mexican tequila bats, about her work and its potential impact.
“Normally there’s no threat to humans from bats,” says Elizabeth. “We think that what has happened recently with climate change and habitat devastation, these types of events have occurred more often giving rise to zoonotic diseases. We have to be very careful when we publish the results because we don’t want to continue with the persecution of bats. If we demonstrate that these events have an impact on the immune system and viral shedding, we will understand better the zoonotic outbreaks and we will also generate more information so that people understand that they have to respect their habitat and that we can coexist without risk.”
Listen to the Genetics Unzipped podcast
Listen to the whole episode and find show notes and a full transcript at GeneticsUnzipped.com.
Genetics Unzipped is the podcast from the UK Genetics Society, presented by award-winning science communicator Dr Kat Arney and produced by First Create the Media. Follow Genetics Unzipped on Twitter @geneticsunzip, and the Genetics Society at @GenSocUK