Our Year 12 Biology students examined the story of the Tasmanian Devil, focusing on devil facial tumour disease (DFTD) and how our understanding of this devastating illness has evolved over time. They learnt first-hand how Zoos Victoria is currently working to save Tasmanian Devils through both in-situ and ex-situ breeding and research programs, and how the concepts they have learnt about in VCE Biology are being used in real life to save this endangered species. Students also considered the ethical dilemmas faced when trying to save an endangered species, and contemplated how understanding a new type of contagious disease in our increasingly globally connected world could have unforeseen importance in the future.
The DFTD within the Tasmanian Devil population could result in devil extinction. However, emerging research reveals that this disease is a strong selection pressure leading to changes in areas of the devil genome related to immune function and cancer risk. This research suggests that Tasmanian devils are evolving resistance to DFTD.
Students analysed DNA samples that were collected from Tasmanian devil populations before and after the emergence of DFTD. They used bioinformatics tools to search for Single Nucleotide Polymorphisms (SNPs) that have changed in frequency in the population as a response to the DFTD selection pressure. These regions, that show strong positive selection, contain genes. Students conducted a nucleotide BLAST to identify what the genes might be.
In the laboratory students considered a potential biotechnical application for selecting captive devils for reintroduction into the wild. Using DNA manipulation techniques they determined the alleles that a devil has for a gene thought to confer resistance to DFTD.