BAT GENOMES

• Bats typically have large and complex genomes. The genome size varies among different bat species, but many have genomes that are relatively large compared to other mammals.
• Bats are one of the most genetically diverse groups of mammals. This diversity allows them to adapt to a wide range of ecological niches, from fruit-feeding bats to insect-eating bats
• Bats have undergone specific genetic adaptations to support their unique ability to fly. This includes changes in genes related to wing development, muscle structure, and energy metabolism
• Bats are known for their use of echolocation, a system of using sound waves to navigate and locate prey. Genes associated with echolocation have been of particular interest in bat genomics
• Comparative genomics studies have been conducted to compare bat genomes with those of other mammals. These studies have provided insights into the genetic basis of various traits, such as flight, echolocation, and longevity
• Bats have also been the focus of genomic research related to disease transmission. They are reservoir hosts for several viruses, including coronaviruses, and understanding their genomes can help in disease prevention and management.

• Immunity-related genes have been one of the more well-studied gene classes in bats. The fraction of these genes is also unique in bats: some 2.7-3.5% of the bat genome versus roughly 7% of the human genome.
• Emerging evidence also suggests that a set of immune-related genes have been undergoing positive selection in bats, adapting them to control the spread of viruses while mitigating the antiviral inflammatory response
• One of the first Bat1K genome consortium papers described six high-quality bat species genomes in the journal Nature.
• It suggested that echolocation, loss of pro-inflammatory genes, and expansion of antiviral genes are ancestral traits of bats. This suggests that bats have molecular mechanisms that allow them to host a range of deadly viruses but evade clinical disease.
• Long-read sequencing technologies are those that can ‘read’ thousands to tens of thousands of bases of a genome at a time
• It has become possible today for scientists to quickly assemble the nearly complete whole genomes of organisms. Another benefit to them is that they no longer had to use more complex, time-consuming, and expensive molecular technologies in the pursuit of building complete genomes
• The researchers reported that subsets of genes involved in mounting an immune response – which encode proteins called interferons (IFN) – had contracted significantly. This in turn changed the relative proportions of two subsets, interferon-alpha (IFN-α) and interferon-omega (IFN-ω), relative to each other.
• The researchers attributed bats’
  immune properties to these changes. By shedding the genes for IFN-α, bats can dampen the pro-inflammatoryresponse against a number of viruses, thus protecting themselves from clinical disease.