liquid

A group of researchers are putting forward the possibility that tiny spherical structures found in the body may be an undiscovered form of life, which they are calling 'nanobacteria'.

http://news.bbc.co.uk/1/hi/sci/tech/3729487.stm

Not everyone's convinced based on the evidence so far, but let's see if anything else interesting pops up in the future.

Jet Black

The thing I don't get is why they are so hung up on looking for DNA in them. why not look for a hypercycle of something else? Life wasn't always DNA based, so I see no reason to think it should all be now.

liquid

In fact, I think it would be more interesting if we did find something non-DNA based.

stray bullet

If it is living and self-reproducing, I'm curious as to how they obtain the energy to do so.

SonicHedgehog

It would be a lot more interesting if the nanobacteria weren't DNA-based. That would point to a primarily RNA-based life form, given RNA's ability to self-replicate itself and the evidence that these nanobacteria absored uridine.

Yeah, the energy question is bugging me, though I'm guessing the energy might come from the host itself. It's just a guess... Anyone else here with knowledge of nucleic acid biochemistry wanna add to that?

SH

stray bullet

I think the answer lies in how they are causing problems in humans. As far as nucleic acids, ATP/GTP are known energy sources in all sorts of living cells, UTP and CTP also are used in oxidation/synthesis of di/poly-saccharides and fats/membranes respectively.

- However, I don't see anything in the article about the cells taking in RNA precursors.

SEF

I think one way to start would be the smash-em-to-bits and count the atoms approach - a primitive approach (if one is allowed to call use of a hi-tech mass spectrometer that!) but effective in that it would indicate by the proportions what sort of inorganic/organic thing they have. For example, if they found they had mostly calcium there it would be rather telling (perhaps fat soluble vitamins/proteins and minerals clustering). If they had C H N O etc in interesting proportions and only minimal amounts of other elements, that would point to something more organic in one sense at least.

Roland98

This was when I was in college, and the micro profs were very skeptical. As mentioned in the article, it's simply too small to contain the DNA and proteins we think are necessary for life. And if it's not DNA-based, then trumpeting that they stain for it is rather strange. If it is DNA-based, then why can't it be extracted? It would be exciting if these are indeed involved in disease, but I'm not convinced they're actually "nanobacteria" yet.

Gooch's dad

Fascinating stuff...but the only evidence that they have for "life" is that the liquid's optical density increased? This bugs me a bit. They ran the stuff through a bunch of filtration first, it seems that reactions with the "sterile medium" might be occurring, and the reaction products might absorb more light. I'd like to know what they used to measure the optical density (how many wavelengths of light they used).

There are some microscopy techniques that might work to take apart those little buggers. A company here in Madison makes a microscope system that can apparently take something apart molecule by molecule.

Weird that they couldn't find any nucleic acids in the buggers either.

Doubting Didymus

Hmm. I don't want to give anyone fuel for wildly unsupported speculation, but aren't these little blighters about the same size and shape as those so-called "bacteria" fossils from mars? i.e. <about 200nm