Bats can fly and orient themselves effortlessly in total darkness with the help of echolocation; they survive deadly diseases and are surprisingly resistant to aging and cancer. Researchers have now for the first time almost completely deciphered the genetic material of bats, which is responsible for the unique adaptation and superpowers of these animals.
Bat1K is a worldwide consortium of scientists dedicated to sequencing the genetic make-up of each of the 1421 live bat species. Now these scientists have created and analyzed six high-precision bat genomes. These are ten times more complete than all previously published bat genomes. They form the basis for exploring the unique properties of bats.
“We can now better understand how bats tolerate viruses, slow down aging, and develop flight and echolocation. This knowledge of the genetic properties of bats may help human aging processes and diseases in the future,” says Emma Teeling, lead author from University College Dublin and co-founder of Bat1K.
The researchers have deciphered the bat genomes using the latest technologies from the DRESDEN-concept Genome Center (DGC). The DGC is a collaborative state-of-the-art technology platform in Dresden, Germany. The team was able to sequence the BAT’s DNA and develop new methods to assemble the individual parts in the correct order and determine the existing genes.
“With the latest DNA sequencing technologies and new computer methods for such data, we have reconstructed 96 to 99 percent of each bat genome at the chromosome level in an unprecedented quality. This is comparable, for example, to the current quality of the human genome – the result of more than a decade of intensive efforts. Therefore, these bat genomes provide an excellent basis for experiments and evolutionary studies of the fascinating abilities and physiological properties of these animals,” said Eugene Myers, lead author and director of the Max Planck Institute for Molecular Cell Biology and Genetics and the Center for Systems Biology in Dresden.
The team compared these bat genomes with 42 other mammals to answer the still contentious question of where bats are located in the mammals’ pedigree. Using novel methods and comprehensive molecular data sets, the team found that bats are most closely related to a group called Ferungulata. These include carnivores (e.g. dogs, cats and seals), scale animals, whales and ungulates (hoof mammals).
To detect the genomic changes that led to the unique adaptations of bats, the team systematically searched for genetic differences between bats and other mammals. The researchers found regions in the genome that evolved differently in bats. Thus, genes were lost in the course of evolution or new ones were added that might have influenced the unique properties of bats.
“Our genome-wide searches have found changes in the genes responsible for hearing. These changes could contribute to echolocation. In addition, we have discovered duplications of antiviral genes, changes in immune system genes, and loss of genes that promote inflammation. These changes could contribute to the exceptional immunity of bats and their tolerance to coronaviruses,” explains Michael Hiller, lead author and head of the research group at the Max Planck Institute for Molecular Cell Biology and Genetics in Dresden, at the Max Planck Institute for the Physics of Complex Systems, and at the Center for Systems Biology Dresden.
The team also found evidence that bats’ ability to tolerate viruses is reflected in their genomes. The high-quality genomes contained “fossil virus sequences” from a wide variety of viruses. This shows that bats have survived viral infections in the past.
The high quality of bat genomes has allowed the team to clearly identify and experimentally confirm several regulatory regions in the genome. These regions may have influenced the main evolutionary developments of bats.
“With such complete genomes, we were able to identify regulatory regions that control the activity of the genes that are unique to bats. In particular, we were able to check specific bat micro RNAs in the laboratory to show their effects on gene regulation. In the future, we could use these genomes to understand how regulatory regions and epigenomics contributed to the extraordinary adaptations,” said Sonja Vernes, lead author and co-founding director of Bat 1K, Max Planck Institute for Psycholinguistics, Nijmegen, Netherlands.
But this is just the beginning. The remaining 1,400 live bat species have an incredible diversity in terms of ecology, longevity, sensory perception and immunology. The genetic basis of these spectacular properties is still unclear, many questions remain unanswered. Bat1K will help answer these questions as more and more high-quality bat genomes are generated and thus the genetic basis of the wonderful superpowers of bats can be further explored.