While the UK and US are just out of the ‘pandemic phase’ for Covid-19, scientists are already eyeing the next global health crisis – and say it could be triggered by a microbe trapped in a Tibetan glacier.
Researchers from Lanzhou University studied 21 glaciers on the Tibetan Plateau and found evidence of 968 microbes, most of which have never been seen before.
Disturbingly, the team also identified more than 25 million protein-coding genes, including some that could affect the ability to cause disease.
“Modern and ancient pathogenic microbes trapped in ice could lead to localized epidemics and even pandemics,” the researchers write in their study published in Nature Biotechnology.
Researchers from Lanzhou University studied 21 glaciers on the Tibetan Plateau and found evidence of 968 microbes, most of which have never been seen before
Researchers sequenced 883 bacterial genomes from cultured glacial bacteria and 85 metagenomes from 21 Tibetan glaciers covering different habitats including snow (bottom left map), ice (top left map) and cryoconite (top right map).
The Tibetan Plateau
The Tibetan Plateau is an important source of water for some of the world’s largest rivers, which means dangerous microbes can quickly reach large numbers of people.
‘Known as the water tower of Asia, the Tibetan Plateau originates from several of the world’s largest rivers, including the Yangtze, Yellow River, Ganges and Yarlung Tsangpo (Brahmaputra River),’ the researchers explained.
“The release of potentially dangerous bacteria could affect the world’s two most populous countries: China and India.”
In the study, the team collected bacteria and microscopic life forms called archaea from 21 glaciers on the Tibetan Plateau from 2016 to 2020.
Using genetic sequencing, the researchers uncovered evidence of 968 species of microbes.
Some of the microbes are widespread such as Pseudomonas aeruginosa found in soil and water.
However, it has been found that the vast majority (82 percent) share little genetic similarity to microbes found in other environments.
Eleven percent of the species were found in just one glacier, while 10 percent were found in almost all glaciers surveyed.
The team also discovered more than 25 million protein-coding genes – including some that could affect the ability to cause disease.
“Here we present the first, to our knowledge, dedicated genome and gene catalog for glacial ecosystems, comprising 3,241 genomes and composite metagenome genomes and 25 million non-redundant proteins from 85 Tibetan glacial metagenomes and 883 cultured isolates,” the researchers wrote.
The results suggest many microbes have evolved to withstand extreme conditions, the team said.
‘The surfaces of glaciers harbor a wide variety of life forms, including bacteria, algae, archaea, fungi and other microeukaryotes,’ they explained.
“Microorganisms have demonstrated that they can adapt to these extreme conditions and contribute to vital ecological processes.
Some of the microbes are widespread such as Pseudomonas aeruginosa found in soil and water. However, it has been found that the vast majority (82 percent) share little genetic similarity to microbes found in other environments
“Glacial ice can also serve as a record of microorganisms from the past, successfully reviving ancient (more than 10,000 years old) airborne microorganisms.
“Therefore, the Ice Age microbiome also represents an invaluable chronology of microbial life on our planet.”
The Tibetan Plateau is an important source of water for some of the world’s largest rivers, meaning that if released, dangerous microbes could quickly reach large numbers of people.
‘Known as the water tower of Asia, the Tibetan Plateau originates from several of the world’s largest rivers, including the Yangtze, Yellow River, Ganges and Yarlung Tsangpo (Brahmaputra River),’ the researchers explained.
“The release of potentially dangerous bacteria could affect the world’s two most populous countries: China and India.”
Worryingly, a 2019 report by the Intergovernmental Panel on Climate Change (IPCC) warned that up to two-thirds of the Tibetan Plateau’s remaining glaciers will disappear by the end of the century.
A third of the ice is expected to be lost during that time – even if global warming is limited to 2.7°F (1.5°C) above pre-industrial levels.
The team hopes the project, which they call the Tibetan Glacier Genome and Gene (TG2G) Catalog, will be useful to researchers in the future.
“The TG2G catalog provides a database and platform for archiving, analysis and comparison of glacier microbiomes at the genome and gene level. It is particularly timely as glacial ecosystems are threatened by global warming and glaciers are retreating at an unprecedented rate,” they concluded.
“We anticipate that the catalog will form the basis for a comprehensive global archive of glacial microbiome data.”
The research was published in Nature Biotechnology.
HOW DO VIRUSES WORK?
A virus particle, or virion, consists of three parts: a set of genetic instructions, either DNA or RNA; protein coat that surrounds the DNA or RNA to protect it; a lipid membrane surrounding the protein shell.
Unlike human cells or bacteria, viruses do not contain the chemical machinery called enzymes needed to carry out the chemical reactions needed to divide and spread.
They only carry one or two enzymes that decode their genetic instructions and need a host cell, such as a bacteria, plant or animal, in which to live and produce more viruses.
When a virus infects a living cell, it hijacks and reprograms the cell to turn it into a virus-producing factory.
Proteins on the virus interact with specific receptors on the target cell.
The virus then inserts its genetic code into the target cell while breaking down the cell’s own DNA.
The target cell is then “hijacked” and begins using the virus’s genetic code as a blueprint to produce more viruses.
The cell eventually ruptures to release the new, intact viruses, which then infect other cells and begin the process again.
Once freed from the host cell, the new viruses can attack other cells.
Because a virus can reproduce thousands of new viruses, viral infections can spread quickly throughout the body.