China scientists discover giant viruses

[reader]

Let's see if I've go this right. A huge virus, buried in the seabed at a depth of 36,000 feet, is brought to a laboratory in Shanghai for sequencing.

What could possibly go wrong?

From South China Morning Post  / BP

The first known batch of viruses retrieved from the deepest point in the Mariana Trench includes giant species bigger than some bacterium, according to a research team in Shanghai.

The many legends of giant sea creatures have been largely debunked because of the challenges to large, complex life forms at the greatest ocean depths.

But the researchers discovered several giant viral species, including mimiviruses - which typically use amoeba as their hosts - in sediments taken from a seabed nearly 11,000 metres (36,000 feet) below sea level at Challenger Deep.

And, while giant viruses have been found elsewhere, they appeared to be more abundant at the extreme depth, where pressure is 1,100 times that of the atmosphere, than in other conditions, where they are usually rare.

Previous attempts to obtain viral samples from Challenger Deep failed because of the extreme technical challenges but samples collected five years ago by the advanced research ship Zhang Jian yielded enough material for the team to obtain genome sequences of 15 different types of viruses and more than 100 kinds of other microorganisms.

The researchers also raised more than 2,000 strains of microorganisms in a high pressure laboratory environment, although they were unable to revive any of the viruses, according to a paper published this month in the journal Genome Biology.

Mimiviruses -- which made up more than 4% of the total viral population in the sampled seabed -- were initially mistaken for bacteria when scientists first saw them during a pneumonia outbreak in 1992. With their hairy fibres and bodies which can be up to 700 nanometres wide, they can sometimes be visible to the naked eye.

In some experiments, these giant viruses were able to cause tissue damage in mammals, but so far there is no evidence they can directly harm human beings.

Continues at

https://www.bangkokpost.com/world/2154471/china-scientists-discover-giant-viruses-in-the-deepest-place-on-earth