CRISPR-like ‘immune’ system discovered in giant virus | Hacker News Reader

CRISPR-like ‘immune’ system discovered in giant virus

nature.com

131 pointsAmorymeltzer20 comments

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Getting a look at that mimivirus makes me think whatever gets infected by it failed its saving roll.

I think you mean "role", though I love the image of a virus rolling a d6 to determine whether it succeeded or failed.

What, did you see the picture?

That virus is literally a D20.

pretty much all virii are "D20"s.

Really? The pictures I've seen of ebola make it look like spaghetti.

You're quite right, GP is being mistakenly over-broad. Mimivirus (APMV) is an encapsidated virus, and the capsid is what forms that shape. Capsids[1] generally contain the DNA or RNA of the virus' genome and often appear quite geometric. Capsids have a T-number, which determines how many faces of triangles or hexagons+pentagons exist. It's a deeply mathematical field of study since these are, essentially, tiny repetitive building blocks.

Some (tobacco mosaic virus being the most famous) are helical, while others (bacteriophages) look completely different[2]. Viruses appearing spherical are generally enveloped, meaning they contain part of the cellular plasma membrane surrounding their capsid (HIV). Ebola is part of the filovirus family[3], which are characterized by, among other things, their long, filamentous shape (hence the name).

1: https://en.wikipedia.org/wiki/Capsid

2: https://en.wikipedia.org/wiki/Bacteriophage

3: https://en.wikipedia.org/wiki/Filoviridae

this is fascinating... makes me want to go back to school and study viruses (what field would that be?)

Virology, I believe.

Bacteriophages are often icosahedral in the headpiece. In fact, the packing motor portion of the icosahedral bacteriophage was not solved until recently because the symmetry averaged structure washed out the stalk part in crystallography and cryo-EM techniques. (it was machine-vision-assisted cryo-EM class averaging technique that helped elucidate the structure)

Yes, there are some filamental viruses such as TMV and ebola, and the P22 bacteriophage, but most viruses, even membrane-enveloped ones, seem to have icosahedral or pseudo-icosahedral structures.

My original point being: "d20"-ness is the rule, not the exception.

"Virii" isn't a generally acceptable plural form of "virus", and was only really a thing because the insular 90's hacker community started using it to refer to computer viruses. https://en.wikipedia.org/wiki/Plural_form_of_words_ending_in...

https://en.wikipedia.org/wiki/Capsid doesn't seem to say which ones are d12's, but it's in the list! Pretty neat.

the d12 ones are effectively equivalent to d20s because an icosahedron is the dual solid of the dodecahedron; depending on "how you look at it", T1 virus capsids can either be "d20s" or "d12s".

I think "roll" is the right term. You "fail" the roll of the die, you get infected.

D&D is a role playing game, but you roll the dice to see what happens.

Really makes you wonder if viruses were the first forms of life, contrary to popular opinion.

No. The viruses were probably the second. You need some form of self replicating metabolism, before having a virus to be able to feed on it.

I would imagine the earliest forms of life (proto-life if we use cellular structure in the definition of life) were free-floating strands of genetic material, more similar to viruses than to fully formed cells. Or if that's on the right track, we could say the first "cells" were large bowls of the primordial soup.

Take a look at the videos at this link. (the ones showing the fatty acids holding onto each other)

http://exploringorigins.org/fattyacids.html

There is a related Radiolab episode: http://www.radiolab.org/story/shrink/

Fascinating article, but it was hard for me to get past 'Immune defence'. I'm sure they meant no offence, but it coloured the rest of the text for me. (If it had been on a .co.uk, I'd have left them alone, scout's honour).

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