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View Full Version : Koala bears in danger of extinction? Passing viral genes to our offsprings.


Wise Young
11-24-2006, 03:36 PM
A recent paper in Genome Biology suggested that koala bears may be in danger of extinction, not necessarily from habitat destruction which nearly drove them into extinction about a hundred years ago (Source (http://en.wikipedia.org/wiki/Koala)), but from a retrovirus infection. According to an article by Tarlinton, et al. (2005) in the Journal of General Virology (Source (http://vir.sgmjournals.org/cgi/content/full/86/3/783)), the Koala Retrovirus (KoRV) inserts a full length replication competent into cells in koalas and that this leads to leukemia and lymphoma in the animals. It also seems to increase koala susceptibility to chlamydiosis and contributes to blindness, infertility, urinary tract infections, and pneumonia in the koalas (Source (http://www.wildlifewarriors.org.au/research/koalas.html)). The retrovirus is similar to the feline leukemia virus in cats. However, the virus incorporates itself into the koalas and is transmitted to offsprings (Source (http://www.abc.net.au/news/newsitems/200607/s1680261.htm))

This way for a virus to spread is alarming. It is neither new nor restricted to koalas. There are many examples of viral genes that are incorporated into our genomes.



http://genomebiology.com/2006/7/11/241/abstract
Minireview

Koala retrovirus: a genome invasion in real time
Jonathan P Stoye
Division of Virology, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK

Genome Biology 2006, 7:241 doi:10.1186/gb-2006-7-11-241

Published 21 November 2006

Subject areas: Evolution, Virology

Abstract

Koalas are currently undergoing a wave of germline infections by the retrovirus KoRV. Study of this phenomenon not only provides an opportunity for understanding the processes regulating retrovirus endogenization but may also be essential to preventing the extinction of the species.

timmy78
11-25-2006, 02:46 AM
sorry to be picky but they are not koala bears just koalas

IanTPoulter
11-25-2006, 02:59 AM
Wikpedia has some interesting information on Koalas including the fact that a Koala fingerprint is very similar to a humans which apparently is a sign of convergent evolution
http://www.bbc.co.uk/dna/actionnetwork/A14608541
Henneberg had stumbled upon a perfect example of convergent evolution. This means that different species in different parts of the world develop the same physical characteristics for the same purpose2 (http://www.bbc.co.uk/dna/actionnetwork/A14608541#footnote2) Just like our ape ancestors, the koala has developed fingerprints in order to achieve a better grip while climbing
. They also eat only eucalyptus leaves in contrast to its closest living relative, a wombat which eats roots shoots and leaves.
http://en.wikipedia.org/wiki/Koala
A Koala also has an unusually small brain.