Although low genetic diversity may contribute to DFTD susceptibility, experiments have indicated that devils are normally capable of mounting immune reactions to allogeneic grafts ( Kreiss et al., 2011 Siddle et al., 2007).ĭFTD is one of two known naturally occurring clonally transmissible cancers, the other being the canine transmissible venereal tumor (CTVT) of dogs ( Murchison, 2009). The mechanism whereby the clone avoids immune rejection during colonization of allogeneic hosts remains unknown. DFTD is believed to be of neural crest origin, and the cancer cells express a number of genes of the Schwann cell lineage ( Loh et al., 2006b Murchison et al., 2010). Tasmanian devil facial tumor disease (DFTD) is a single cancer lineage spread by the horizontal transfer of living cancer cells.ĭFTD spreads by the direct transfer of living cancer cells, usually through bites inflicted on the face during mating and feeding interactions ( Hamede et al., 2008 Pearse and Swift, 2006). Epidemiological studies have documented the expansion of the disease down the east coast of Tasmania and its continuing progression toward the west coast ( Hawkins et al., 2006 Lachish et al., 2007). The cancer has spread rapidly through the Tasmanian devil population and has been associated with devil population decline ( Hawkins et al., 2006 Lachish et al., 2007). Most commonly observed in sexually mature individuals of 2 years or older, DFTD occurs equally in male and female devils ( Hawkins et al., 2006 Loh et al., 2006a). The disease is characterized by the appearance of tumors, usually on the face and inside the mouth of affected animals, which frequently metastasise and usually cause death within months ( Figure 1) ( Hawkins et al., 2006 Lachish et al., 2007 Loh et al., 2006a). The species has limited genetic diversity, although three genetically distinct geographically defined subpopulations have been described ( Jones et al., 2004 Miller et al., 2011).ĭFTD was first observed in northeastern Tasmania in 1996 ( Hawkins et al., 2006). They are seasonal breeders and females rear a maximum of four pouch young each year ( Owen and Pemberton, 2005). Tasmanian devils are solitary nocturnal scavengers that weigh up to 12 kg and generally live for 5 or 6 years in the wild ( Owen and Pemberton, 2005).
The Tasmanian devil ( Sarcophilus harrisii) is a marsupial carnivore endemic to the island of Tasmania, Australia. The genomes of the Tasmanian devil and its transmissible cancer, DFTD, are thus of interest both from the perspective of conservation of a threatened species as well as for the insights they may provide into the origins, somatic evolution and population genetics of an extraordinarily divergent neoplastic clonal lineage.
This cancer has spread through the Tasmanian devil population and is threatening the species with extinction ( Hawkins et al., 2006 McCallum et al., 2009). Tasmanian devil facial tumor disease (DFTD) is an unusual cancer that has survived beyond the death of the individual that spawned it by acquiring adaptations for transmission between hosts. Although natural selection operating on cancers favors the outgrowth of malignant clones with replicative immortality, the continued survival of a cancer is generally restricted by the life span of its host. Stratton 1, ∗Ĭancers are clonal cell lineages that arise due to somatic changes that promote cell proliferation and survival. Papenfuss, 4, 10 P. Andrew Futreal, 1 Peter J. Woods, 7 Niall Gormley, 2 Sean Humphray, 2 Gary Schroth, 6 Geoffrey Smith, 2 Kevin Hall, 2 Stephen M.J. McBride, 1 Lisa Murray, 2 Anne-Maree Pearse, 8 Keiran Raine, 1 Isabelle Rasolonjatovo, 2 Richard Shaw, 2 Philip Tedder, 2 Carolyn Tregidgo, 2 Albert J. Harris, 1 Irina Khrebtukova, 6 Zoya Kingsbury, 2 Mark Kowarsky, 4 Alexandre Kreiss, 7 Shujun Luo, 6 John Marshall, 1 David J. Cox, 2 Zhi-Ping Feng, 4, 5 Yong Gu, 1 Russell J. Bignell, 1 R. Keira Cheetham, 2 William Cheng, 1 Thomas R. Bauer, 2 Beiyuan Fu, 1 Matthew Hims, 2 Zhihao Ding, 1 Sergii Ivakhno, 2 Caitlin Stewart, 1 Bee Ling Ng, 1 Wendy Wong, 2 Bronwen Aken, 1 Simon White, 1 Amber Alsop, 3 Jennifer Becq, 2 Graham R. Schulz-Trieglaff, 2 Zemin Ning, 1 Ludmil B.
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