Global Courant 2023-05-23 14:01:46
The only flying mammals are divided into more than 21 families and 1,300 types, whose genes are currently being studied in order to find the key that answers the secret that regulates their immune system.
Bats -which is about them- are not only the animals that the Covid narrative has located as triggers for the first infections in the Chinese city of Wuhan, but also seem to be the key that would help humans fight a next pandemic.
Different scientific institutions from around the world participate in the research, baptized Bat1K, which -as they have already announced- have deciphered the genome of 80 species of bats.
“The answer has to do with its ability to fly,” explained Emma Teeling, a researcher at the University of Dublin, one of the directors of the work involving some 180 scientists from different countries.
Teeling gave some details about the progress of the research in an article in The Guardian, slipping into why bats would have an enormous capacity to harbor viruses without getting sick.
A fish and turtle vendor at the Wuhan market in January 2020, where Covid was discovered in January 2020. Photo: AFP
According to his argument, the flight is enormously demanding and requires the expenditure of a lot of energy. The idea is that the release of this energy within a mammal’s body should lead to the breakdown of some of its cells. And you would expect bits of DNA to break off and float around your body.
“Given the high metabolic requirements of flight and the high levels of damaging free radicals that are generated, bats had to evolve a unique immune system to rapidly reduce the constant inflammation they experience from such cell damage,” Teeling added.
In flightless mammals, those pieces of genetic material are identified by immune cells and are often treated as signs that an invasion by a disease-causing pathogen is underway.
From that reaction, the body launches a counterattack that can trigger an inflammatory syndrome. In many cases, including Covid-19, this inflammation is often the main cause of severe reactions that can lead to death.
“Bats lack that intense response,” Teeling explained. Over the course of their evolution, which began around 80 million years ago, they have modulated their immune systems so that their responses have been dampened. The inflammation does not occur as often or as severely. As a result they can carry all these viruses without suffering dangerous reactions.”
The international consortium aims to decipher the genome of some 1,300 species of bats. Photo: AFP
Which would mean that bats, because they evolved to be able to fly, had to evolve immune systems that are much less likely to trigger that damaging inflammation.
That would be the key that would put them in a position to face viruses without suffering the intense reactions that affect other mammals. Since it’s unclear how they achieve this, the Bat1K project is looking to be the one to answer it.
The initiative, strictly speaking, predates the Covid pandemic. Its origin was in 2017, but depending on subsequent events and the uncertainty generated by the health future of humanity, the data it can provide now seems to become more relevant.
Another of the directors of the consortium, Sonja Vernes from New Zealand, assured in a presentation of the project that all the data collected would form a public platform available to any interested party, something that today is already a reality on the site. www.bat1K.com. In turn, periodic newsletters allow us to follow the evolution of the work.
Online presentation by Sonja Vernes of the project that has already described 80 bat genomes.
Genome and longevity
The research involves researchers from the University of St. Andrews, the Max Planck Institute for Molecular Cell Biology and Genetics, in Dresden, and the Sanger Institute, near Cambridge.
The goal is to create high-quality genomes for all bat species. Thus they could decipher the complete instructions of the DNA carried by the 1,288 registered species of bats.
“The longevity of an animal is usually directly proportional to its size. Bats, however, are an exception to this rule. Brandt’s bat (Myotis brandtii) is the longest-lived bat, with a lifespan of up to 40 years. Mammals that are of a similar weight, such as mice, typically only live 2-3 years. Because? A bat’s ability to fly may have extended its lifespan,” Vernes explained.
There are recent scientific investigations that account for how evolution has allowed bats to optimize their survival.
One of them, on the genome of six species, was published in the journal Natura in 2020. The authors -who participate in the Bat1K group of researchers- explain that they found in the bats analyzed “selection and loss of genes related to immunity ( including the pro-inflammatory regulators NF-κB) and APOBEC3 antiviral gene expansions, highlighting molecular mechanisms that may contribute to the exceptional immunity of bats.” And he adds that “the genomic integrations of various viruses provide a genomic record of historical tolerance to viral infection in bats.”
The Bat1K consortium website, where the material collected so far is available.
To the extent that they can pinpoint the ways in which bats resist the viruses they harbor and transform into asymptomatic hosts, the goal is to use that data to develop drugs that can mimic that behavior in people.
If it comes to fruition, the “Batman” would stop being just a fiction invented in the United States, the superhero who fights against the underworld, to also become a creation of science against a number of potentially fatal diseases.
In short, it is a race against time in laboratories against pathogens. Some experts already predict that the next pandemic could occur in approximately a decade, and the unknown is whether basic and applied science will come to provide new weapons that will mitigate its eventual impact.
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