The Virosphere: Welcome to this new expanding world

Scientists have discovered 1,500 new viruses. Though very small & hard to see, viruses are everywhere.

SCIENCE

The Virosphere: Welcome to this new expanding world

Scientists have recently discovered nearly 1,500 new viruses, the largest discovery to date.

An international research team led from Australia and China published an article in the science journal Nature this week with the new results (see here).

Viruses are much more difficult to see than larger microorganisms such as bacteria, which can be seen under a regular microscope.

Because they are so small, scientists were uncertain whether viruses were as numerous and exist everywhere (ubiquitous) as bacteria do.

WE KNOW MORE ABOUT BACTERIA

Because bacteria are a lot larger than viruses, we already know a lot more about bacteria.

Bacteria were among the first forms of life to appear on planet earth and can be found everywhere on earth.

Bacteria inhabit our intestine helping you to digest food, they live in the soil, deep under the earth, at the bottom of the sea, in radioactive waste and even in highly acidic hotsprings.

There is hardly a place on earth where bacteria are not to be found.

There are a million bacteria in a single millilitre of water and in one gram of soil there are about 40 million bacteria.

Lumped together their biomass would exceed all plants and animals on earth. 

Bacteria are very small, only a few micrometres in length, but can be seen with and were first discovered with, an ordinary light microscope, unlike a virus.

Bacteria have many different shapes from spheres to rods and spirals (for more on bacteria see Wikipedia here).

IDENTIFYING VIRUSES

In a first step to unlock the world of viruses (the virosphere studied by virologists) scientists began looking at the viruses that infect invertebraes.

It turns out, viruses have been infecting invertebrae animals for billions of years (watch BBC special on the origin of viruses here).

Invertebrae are animals without a backbone or spine (vertebral column) and this includes insects, spiders and worms, a slippery snail being a particularly good example of an invertebrate.

NEW RNA SEQUENCING TECHNOLOGY

Viruses are so small and simple that they do not quite qualify as living things.

Everyone knows about DNA, the blueprint of life that makes up our genomes.

Viruses use a different chemical to build their genomes, namely RNA, so new genetic sequencing techniques are needed.

The potential for discovering new viruses with the new technology is great.

THE RESEARCH PROJECT

In the research project, 220 different species of invertebrae living in the water and land of China were collected.

Many of the viruses discovered in the project did not easily fit into the existing virus family tree, meaning that their discovery was truly new and a contribution to knowledge.

Over time viruses exchange genetic material to create new species. This is another finding of the study. 

Viruses have been infecting invertebrae for possibly billions of years.

Some invertebrae do carry viruses such as Zika and dengue that can infect humans.

Some diseases such as influenza which infects humans are, in fact, derived from bacteria that infect invertebrae.

The virosphere of identified viruses is set to explode in the future.

This, however, is not a bad thing but will likely help scientists better cope with future viral outbreaks such as Ebola.

Watch the rest of the videos in the course here , This Week in Virology here and  Virus Watch here.

http://www.bbc.com/news/science-environment-38095585

https://en.wikipedia.org/wiki/Bacteria

http://www.nature.com/articles/nature20167.epdf

สามารถฝึกอ่านออกเสียงและดูคำแปลได้ที่ : http://www.bangkokpost.com/learning/learning-from-news/1145912/the-virosphere-welcome-to-this-new-expanding-world