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Persistence of plasmid
DNA in different soils
Meenakshisundaram
Kandhavelu* and S. John Vennison*
Post
graduate and Research Department of Zoology (Division of
Biotechnology), The American College, Madurai Kamaraj
University, Madurai, Tamilnadu, India.
*Corresponding authors.
E-mail:
imsk1982@gmail.com,
sjvennison@rediffmail.com. Tel: 0452-2530967. Fax :
0452-2520711.
Accepted
15 July, 2008 |
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Natural
genetic transformation is believed to be the essential
mechanism for the attainment of genetic plasticity in many
species of bacteria. Dying cells are likely to release naked
DNA that may survive for many hours. Although numerous
studies have shown that horizontal gene transfer between
distantly related genera, but how long that DNA persists in
the environment is yet be reported. We present evidence from
studying the plasmid DNA retaining capability of different
sterilized/abiotic soils (red, black, river, silt and loose
sand soils). The study also explains how long DNA molecules
are in the active transformable form in the above soils.
Plasmid DNA after purification was quantified and 2 µg DNA
was mixed in 2 kg of sterile soils having less than 20%
moisture and experimental set up was maintained in
laboratory conditions at 31ºC. Every 7 days 1 g of soil was
taken, DNA purified from it and then that DNA was used for
transformation with the E. coli DH5α competent cells
and the results showed that DNA would persist till 35 days
and it had transforming ability.
Key
words:
Horizontal gene transfer, plasmid pUC18, persistence,
abiotic. |
