[meteorite-list] DNA Discovered, Algae Cultured From 'Red Rain'

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed Jun 7 00:07:11 2006
Message-ID: <200606061514.IAA20004_at_zagami.jpl.nasa.gov>

http://www.newscientistspace.com/article/mg19025453.100-red-rain-puzzle-is-still-up-in-the-air.html

'Red Rain Puzzle is Still Up in the Air'
by Hazel Muir
New Scientist
March 31, 2006

When red rain fell over southern India in 2001 it was
sensationally suggested that the red particles in the rain could
be alien microbes. Now, after weeks of analysis at two labs in
the UK, microbiologists are still struggling to identify them.
It sounds like an episode of The X-Files, but a down-to-Earth
explanation is looking the more likely outcome.

Astronomer Chandra Wickramasinghe is studying the cells with
microbiologists at Cardiff University. "As the days pass, I'm
getting more and more convinced that these are exceedingly
unusual biological cells," he says.

The red rain fell sporadically over Kerala during two months in
2001. Godfrey Louis, a physicist at Mahatma Gandhi University in
Kottayam in Kerala, examined the red particles and, unable to
find DNA, suggested that they might be alien microbes that had
fallen to Earth on a comet (New Scientist, 4 March, p 34).

If so, they would be the best evidence to date of "panspermia",
the theory that primitive life forms fly around interplanetary
space on chunks of rock and ice. However, other scientists who
read Louis's report thought the red particles could be
terrestrial cells that had somehow blown up into the rain
clouds. Suggestions included fungal spores, red algae and
mammalian red blood cells.

At the end of February, Louis sent samples of the red rain to
Wickramasinghe, a champion of the panspermia theory. His team
has analysed the samples, as has a second team led by Milton
Wainwright, a microbiologist at the University of Sheffield.

Both teams say microscopy confirms that the particles are
biological cells. They are not red blood cells because they do
not contain haemoglobin. It's unlikely that they are fungal
spores or red algae. They don't contain chitin, a key component
of fungal cell walls. Nor do they contain the chloroplasts, the
organelles in which photosynthesis takes place, that are typical
of red algae.

But they do, after all, contain DNA. A simple DNA stain test in
Sheffield came back positive. However, more rigorous tests in
Cardiff that try to amplify specific DNA sequences have so far
failed. "That doesn't mean there's no DNA, it means that the DNA
is probably unusual," Wickramasinghe suggests.

The red cells have unusually thick, sturdy walls, and some
contain daughter cells that Wainwright says are puzzling. He
stresses, though, that the cells could be ordinary, terrestrial
organisms he is not familiar with.

Something like the Trentepohlia alga, perhaps? That's the
conclusion of microbiologists at the Tropical Botanic Garden and
Research Institute in Kerala, who say they have cultured the
cells and grown Trentepohlia, an alga common in Kottayam, where
the first report of the red rain originated. Formal DNA
identification awaits.

Both UK teams will continue DNA tests and say they will not
release full details of their results until they have been peer
reviewed. Sadly for X-Files fans, a terrestrial origin is
looking more likely. How the cells fell as rain, that's the
mystery.
Received on Tue 06 Jun 2006 11:14:40 AM PDT