Devil Chromosomes: Basis For Cytogenetic Analysis Of Tumours
Devil Facial Tumour Disease (DFTD) is a large invasive tumour that develops around the mouth and neck of Tasmanian devils and is eventually lethal. The gross, histological and immunohistochemical characteristics of the tumour tissue are consistent with tissue of neuroendocrine origin. Cytogenetic analysis of DFTD cells has revealed a characteristic tumour karyotype exhibiting cytogenetic abnormalities in the way of chromosomal rearrangements. Information regarding the devil genome is extremely limited, with no sequence data available. I will discuss our efforts to sequence and map three genes (ATR, DFFB and TERT) that may be involved in tumourogenesis in the Tasmanian devil. The three candidate tumour genes are found at or near the chromosomal breakpoints in the human neuroendocrine tumour Merkel Cell Carcinoma (MCC), which appears to be similar to DFTD. Using a comparative genomics approach, these genes are being mapped by fluorescence in situ hybridisation (FISH) of BACs containing orthologous sequences from the closely related dasyurid marsupial Sminthopis macroura. This gene mapping endeavour is a step towards the characterization of the Tasmanian devil genome so that we can contribute to an understanding of the genetic basis of DFTD.