Unique Genomic Basis of Superpowered Immune Systems of Bats Could Hold Key to Beating COVID-19 Pandemic

The scientists have generated and analyzed six highly accurate bat genomes that are 10 times more complete than any bat genome published to date, in order to begin to uncover bats’ unique traits. To generate these exquisite bat genomes, the team used the newest technologies to sequence the bats’ DNA, and generated new methods to assemble these pieces into the correct order and to identify the genes present.

The scientists compared these bat genomes against 42 other mammals to address the unresolved question of where bats are located within the mammalian tree of life. Using novel phylogenetic methods and comprehensive molecular data sets, they found the strongest support for bats being most closely related to a group called Ferreuungulata that consists of carnivores (which includes dogs, cats and seals, among other species), pangolins, whales and ungulates (hooved mammals).

To uncover genomic changes that contribute to the unique adaptations found in bats, the scientists systematically searched for gene differences between bats and other mammals, identifying regions of the genome that have evolved differently in bats and the loss and gain of genes that may drive bats’ unique traits. They also found evidence that bats’ ability to tolerate viruses is reflected in their genomes. The exquisite genomes revealed “fossilized viruses”, evidence of surviving past viral infections, and showed that bat genomes contained a higher diversity than other species providing a genomic record of historical tolerance to viral infection. Given the quality of the bat genomes, the scientists uniquely identified and experimentally validated several non-coding regulatory regions that may govern bats’ key evolutionary innovations.

“Our genome scans revealed changes in hearing genes that may contribute to echolocation, which bats use to hunt and navigate in complete darkness. Furthermore, we found expansions of anti-viral genes, unique selection on immune genes, and loss of genes involved in inflammation in bats. These changes may contribute to bats’ exceptional immunity and points to their tolerance of coronaviruses,” said Michael Hiller, Max Planck Research Group Leader at the Max Planck Institute for Psycholinguistics, and senior author.

“Having such complete genomes allowed us to identify regulatory regions that control gene expression that are unique to bats. Importantly we were able to validate unique bat microRNAs in the lab to show their consequences for gene regulation. In the future we can use these genomes to understand how regulatory regions and epigenomics contributed to the extraordinary adaptations we see in bats.” Sonja Vernes, Co-Founding Director Bat 1K, Max Planck Institute for Psycholinguistics, and senior author.

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Max Planck Institute for Psycholinguistics