How bat genomes provide insights into immunity and cancer Premium

Over the years, researchers have unearthed significant insights by sequencing the genomes of many bat species. One watershed moment came in 2013. In a paper published in the journal Science, scientists compared the genomes of a fruit-eating and an insect-eating species and found that genes involved in metabolism and immune response had been positively selected. In the following decade, scientists sequenced a large number of bat genomes. The ambitious Bat1K global genome consortium – to sequence all the 1,400 or so species’ genomes – is also currently underway.

Bats are extraordinary organisms in many ways. They are the only mammals on the earth that can maintain sustained flight. They also have relatively long life-spans and are relatively more protected from a variety of diseases, including cancer. They also have a unique ability in echolocation, whereby they use sound to navigate and locate objects, freeing them from being constrained by the availability of light like humans are.

By population, bats make up 20% of all mammals. There are more than 1,400 species of bats today around the world; more than 60 are endangered and 170-odd are classified as vulnerable. The bumblebee bat weighs only 2 grams whereas the flying foxes, which have a wingspan of 1.5 metres, weigh up to 1.6 kg.

In all bats play crucial roles in maintaining the ecological balance, and are essential for pollination, insect control, etc.

However, bats have grabbed the headlines of late for the wrong reasons. Their notoriety stems from the fact that many deadly viruses use bats as a reservoir host, including coronaviruses, Nipah, Ebola, Marburg virus, and Hendra virus, among others. The COVID-19 pandemic also cast a bright spotlight on the habits of bats.

Bats do host a wide variety of pathogens, including ones deadly to other mammals, but they themselves don’t get infected. Scientists have been curious about the source of this protection.

Scientists’ first object of study is the bat genome. Over the years, researchers have unearthed significant insights by sequencing the genomes of many bat species. Bats are also unique because they have a relatively small genome, around 2 billion bases.

One watershed moment came in 2013. In a paper published in the journal Science, scientists compared the genomes of a fruit-eating and an insect-eating species and found that genes involved in metabolism and immune response had been positively selected. That is, these bats had evolved by improving these two biological domains.