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Post by Shadow on Feb 2, 2006 8:39:11 GMT -5
New Scientist# 01 February 2006 # NewScientist.com news service A BIZARRE infectious cancer seems to be the cause of the fatal facial tumours that are wiping out Tasmanian devils, the world's largest surviving carnivorous marsupial. The disease, which has killed at least a third of the wild population since the mid-1990s, had now infected devils across more than half the island. Early analysis of the tumours suggested that the animals may be passing on cancerous cells during fights (New Scientist, 6 July 2005). Now a team led by Anne-Maree Pearse of Tasmania's department of primary industries has performed a genetic analysis of tumour cells from 37 animals. Results from the first 11 animals reveal that all the tumours contain cells with 13 grossly abnormal chromosomes, instead of the usual 14 healthy ones (Nature, DOI:10.1038/439549a). They were genetically identical whatever their stage of development, suggesting they did not arise in the animals' own tissue. "The cancerous cell line is leading a sort of independent existence," Pearse says. This cell line probably arose in one devil with a cancer, she says. Cancer genomes are usually very unstable, but somehow this line was stable and persistent. The only other known example of a similar "allograft" tumour disease, transmitted by direct transfer, is of a venereal sarcoma that is passed between dogs while mating. From issue 2537 of New Scientist magazine, 01 February 2006, page 20
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