It ’s a dog - eat - dog world out there , and even virus are n’t safe from attack by their own variety . But how does something so little , so round-eyed , protect itself from invaders ? It turns out that some unfeignedly alone virus , called mimiviruses , actually have a kind of antivirus organization that lets them lay in information on assaulter , prepping themselves for next round of assault .
Intriguingly , it seems to forge like the lifelike defence chemical mechanism found in bacterium , called CRISPR , which scientists borrow to create a highly effective and precise factor - editing tool . The presence of such an “ immune system ” only adds to the debate as to whether viruses , or at least some , should be separate as living organism , something that the lead author of this present written report is arguing the subject for , according toNature News .
goliath of the virus existence , mimivirusesmake you think that everything they taught you about viruses in school is a Trygve Lie . evaluate more than 0.7 micrometers across , they ’re seeable under a microscope and touch the size of it of a typical parasitic bacterium . They also hold back more than 1,000 genes , a staggering identification number when compared to a virus like HIV , which has just nine . But what is perhaps most riveting about these massive computer virus is that they possess the equipment to make their own protein , a process that computer virus typically demand to hijack a cellular host for , hence their definition as “ obligate intracellular parasites . ”
It seems the unique nature of these virus does not terminate there , though . Some computer virus fatally taint bacteria , and these are called bacteriophage . Similarly , those that destructively aim viruses are yell virophages , and one in finical has been found to go for mimiviruses . Interestingly , this virophage , squall Zamilon , is only capable of infect certain mimivirus variant , leading researchers to ponder whether some had developed a variety of immunity to them , perhaps similar to the one employ by bacterium – CRISPR .
This system work by the bacterium pull together an archive of routine of genetic material slip from invaders during attacks , which can be used to quickly key out succeeding threat from the same aggressor . If confronted again , the bacteria chops up the aggressor ’s genome and escapes a possible human death . So if viruses have evolved similar tactic , one would expect to find strands of Zamilon stashed away inside the mimivirus , which is precisely what the team from Aix - Marseille University in France search for .
Described inNature , that was indeed the typesetter’s case , with the researchers discovering its genome laced with repeat sequences of Zamilon DNA . And to demonstrate their justificatory intention , the researchers switched off these sequences and presented the resulting mimiviruses with Zamilon , which they were now susceptible to . But this was n’t all they found : Adjacent to these sequence were genes responsible for the debasement of foreign DNA , again resonant of CRISPR . The team has coined this system MIMIVIRE .
“ Our finding illustrate that giant virus have undergone inherited phylogeny that is exchangeable to other bug , ” the researchers conclude . Whether the front of this system is enough to gain the live vs. non - living argument remains to be escort , but it ’s an interesting discovery nevertheless .
Image in text : vanou / Flickr(CC BY - NC - ND 2.0 )
