Institute of Molecular Genetics AS CR, Prague
A molecular biologist explores how new genomic tools can be applied to wild animals.
Some time ago, I learned about a bizarre cancer that is decimating populations of the Tasmanian devil (Sarcophilus harrisii), the carnivorous marsupial popularized by the cartoon character ‘Taz’. Devil facial tumour disease (DFTD) is a rapidly progressive and metastasizing facial cancer caused by a genetically altered cell line that is transmitted between devils by biting.
Studying model organisms in the lab can make the ruthlessness of nature seem distant. But when nature is brought into the lab, one can see the power that modern tools hold for exploring a biological problem — and the limited options available for solving such problems.
Elizabeth Murchison, now at the Wellcome Trust Sanger Institute in Hinxton, UK, and her colleagues performed a comprehensive genomic analysis of the DFTD cells (E. P. Murchison et al. Science 327, 84–87; 2010). They examined not only the nuclear genome, but also that of the mitochondria, cells’ energy-generating organelles. And they performed high-throughput sequencing of RNA molecules, including small RNAs.
Their analysis confirms that DFTD is caused by the transmission of genetically identical cells. The authors also found that DFTD probably originated in Schwann cells, which wrap around neurons, and identified a set of genes that could contribute to DFTD pathology. This is an outstanding example of how next-generation sequencing technologies allow for in-depth analysis of a species that has been difficult to study using other genomic tools.
The data provide diagnostic and monitoring tools that will hopefully help in vaccine development. Until then, Taz’s future lies in the hands of natural selection and conservation efforts that aim to protect healthy animals from DFTD carriers.