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from
Astrobiology Website
Samples of a red rain that fell across the state of Kerala in India
in July-August 2001 have been found to contain microscopic red cells
(Louis and Kumar, 2006) of unknown origin. The early fall was
associated with the 'thunder' and flash of a large meteor. They
report that the cells appear to be very unusual in lacking a nucleus
and DNA. Dr. Godfrey Louis kindly supplied us with a sample of this
material for independent investigation in Cardiff.
High resolution electron microscopy has revealed internal structures
as well as evidence of a replication cycle not commonly found in
either bacteria or yeasts. These images are of thin cell slices
viewed in the transmission electron microscope.
The first (above) shows three cells
around 3 micrometers in diameter, with thick cell walls and a
variety of nanostructures within a membrane, but with no
identifiable nucleus. Apparent holes in the cell wall are real.
The cell on the right has larger holes
and may have lost its cytoplasm.
The second picture shows a cell with
shrunken membrane containing 'daughters' - two have well-defined
cell walls while the third structure may be a further daughter in
the process of development.
The latter picture (scale bar is 300 nanometers) shows the full
resolution of that pictured in New Scientist magazine of 1st April
2006 (No. 2545, p.12;
www.newscientist.com) with the
caption "Does it look alien to you?". New Scientist letters have
also carried various suggestions for known terrestrial
micro-organisms - these pictures should stimulate further ideas!
Further work in progress has yielded positive for DNA using DAPI
staining in the cells and daughters. However, this identification is
not yet fully confirmed, and might be considered equivocal. We hope
to pursue our efforts in extracting DNA (if it exists), amplifying
it and carrying out genetic sequencing, but his work takes time.
References
Persons associated
with this work
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Cardiff University: N.C.
Wickramasinghe, N. Miyake, S.Al-Mufti, M.K.Wallis (CCAB), A.C.
Hann (Biosci. EM Lab), D. Lloyd, S.K. Sheppard (Microbiology
group)
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Mahatma Gandhi University, Kerala.
India: G. Louis and S. Kumar
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