Friday, May 4, 2012

BAC library provides clue to transmissible tumors in Tasmanian devils

The Tasmanian devil was recently listed as an endangered species, primarily due to the emergence of a fatal, transmissible cancer known as devil facial tumour disease (DFTD). The disease was recently reported in Northern Tasmania, and has resulted in depletion of populations that could ultimately make the animals extinct within 25 to 35 years. Recently, Deakin et al. conducted a genetic survey of a BAC library created with the CopyControl™ BAC Library Construction Kit (EcoR I) from genomic DNA extracted from the liver of a deceased two-year-old male Tasmanian devil. Physical maps were compared to the genomes of other marsupials to determine the genesis of this particular disease.

The results showed that massive genomic restructuring appears to be a catalyst for development of the DFTD syndrome, based on chromosome painting and fluorescence in situ hybridization (FISH) experiments conducted using the BAC library. The authors developed a detailed map of the global chromosome restructuring and intricate gene rearrangements that characterize DFTD. Only limited regions of the genome were found to be highly rearranged. After the rearrangements occur, the tumor karyotype is remarkably stable during its clonal transmission from animal to animal. By anchoring genes to a reference and tumor maps, the authors believe that they can predict the locations of common tumor suppressor genes and oncogenes. This study provides an important framework for future genomic studies into DFTD and enhances the value of the creation of large-insert genomic libraries.

ResearchBlogging.orgDeakin, J. et al. (2012). Genomic Restructuring in the Tasmanian Devil Facial Tumour: Chromosome Painting and Gene Mapping Provide Clues to Evolution of a Transmissible Tumour PLoS Genetics, 8 (2) DOI: 10.1371/journal.pgen.1002483

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