World's Largest Virus

Gavinsblog writes "New Scientist is reporting that the largest virus yet discovered may have been found in a water tower in the UK. Dubbed the 'Mimivirus', it may be related to Smallpox. It is not yet known if it causes disease."

Re:"even bigger than some bacteria"

[KewlPC]

That's how all viruses reproduce. They latch onto a host cell and inject their own DNA into it. The virus DNA then proceeds to hijack the cell's reproductive mechanisms, forcing it to make more viruses inside itself until the cell becomes so full of these new viruses that it bursts open and dies, thereby unleashing the newly made viruses.

grade school biologists

[barakn]

1. Not all nucleic acid is injected. At least one bacteriophage appears to be pulled into its host on a pilus. Other methods involve fusion of the viral envelope with the host's cytoplasmic membrane (like two bubbles coalescing into one), or the virus triggering the host into endocytosing it (it gets wrapped up in membrane and swallowed).

2. Some viruses use RNA instead of DNA.

3. Some are released from the host cell via non-lethal means (budding, though budding often is lethal). Many plant viruses require mechanical damage, often from the mouthparts of an insect, to get out. Another method for plant viruses is to travel through cytoplasmic connections between cells, a process that doesn't require lysis (how could a virus burst a plant cell wall anyway?).

4. Some viruses, instead of reproducing, go latent by integrating into the host DNA. Sometimes this triggers the host cell into becoming cancerous. In this case, the host, rather than bursting, becomes "immortal."