Oral Presentation Society for Molecular Biology and Evolution Conference 2016

Chromosome rearrangements in a second transmissible tumour in Tasmanian devils (#232)

Maya Kruger-Andrzejewska 1 , Janine Deakin 1
  1. Institute for Applied Ecology, University of Canberra, Canberra, ACT, Australia

Tasmanian devils are currently under the threat of extinction in the wild due to a transmissible tumour known as devil facial tumour (DFT) disease. Extensive cytogenetic and genetic characterization of tumours from different individuals have supported an allograft theory of transmission, where the tumour cells themselves are the infectious agent. Cases of transmissible tumours are rare but it appears that a second transmissible facial tumour (DFT2) has been identified in individuals from southern Tasmania (Pye et al. 2016). DFT2 is karyotypically and genetically distinct from DFT1 and also appears to be of a different cellular origin. The emergence of a second transmissible raises the question as to whether there are common genomic features shared by these two tumours. As a first step towards addressing this question, we mapped 57 bacterial artificial chromosomes, spread across all six autosomes and the X chromosome, by fluorescent in situ hybridisation. This enabled us to identify chromosome rearrangements in DFT2 and to make comparisons to DFT1. Like DFT1, chromosome 1 is the most rearranged chromosome in DFT2, having acquired fragments from all five other autosomes. Cytogenetically, this is probably the only feature shared between the two facial tumours, although the chromosome rearrangements are quite different between them. Chromosome 1 has also been highly rearranged in the course of marsupial evolution, making it tempting to suggest that this region of the genome in marsupials is more susceptible to breakage and rearrangement than other chromosomes.

 

  1. Pye RJ, Pemberton D, Tovar C, et al. (2016) A second transmissible cancer in Tasmanian devils. Proc Natl Acad Sci 113:374–379