title: Anthropogenic selection enhances cancer evolution in Tasmanian devil tumours.
abstract: The Tasmanian Devil Facial Tumour Disease (DFTD) provides a unique opportunity to elucidate the long-term effects of natural and anthropogenic selection on cancer evolution. Since first observed in 1996, this transmissible cancer has caused local population declines by >90%. So far, four chromosomal DFTD variants (strains) have been described and karyotypic analyses of 253 tumours showed higher levels of tetraploidy in the oldest strain. We propose that increased ploidy in the oldest strain may have evolved in response to effects of genomic decay observed in asexually reproducing organisms. In this study, we focus on the evolutionary response of DFTD to a disease suppression trial. Tumours collected from devils subjected to the removal programme showed accelerated temporal evolution of tetraploidy compared with tumours from other populations where no increase in tetraploid tumours were observed. As ploidy significantly reduces tumour growth rate, we suggest that the disease suppression trial resulted in selection favouring slower growing tumours mediated by an increased level of tetraploidy. Our study reveals that DFTD has the capacity to rapidly respond to novel selective regimes and that disease eradication may result in novel tumour adaptations, which may further imperil the long-term survival of the world's largest carnivorous marsupial.
authors.affiliation: Faculty of Veterinary Science, University of Sydney Sydney, NSW, Australia.
authors.forename: Beata
authors.initials: B
authors.lastname: Ujvari
authors.affiliation: Animal Health Laboratory Department of Primary Industries, Parks and Water and Environment Launceston Tas., Australia.
authors.forename: Anne-Maree
authors.initials: AM
authors.lastname: Pearse
authors.affiliation: Animal Health Laboratory Department of Primary Industries, Parks and Water and Environment Launceston Tas., Australia.
authors.forename: Kate
authors.initials: K
authors.lastname: Swift
authors.affiliation: Animal Health Laboratory Department of Primary Industries, Parks and Water and Environment Launceston Tas., Australia.
authors.forename: Pamela
authors.initials: P
authors.lastname: Hodson
authors.affiliation: Animal Health Laboratory Department of Primary Industries, Parks and Water and Environment Launceston Tas., Australia.
authors.forename: Bobby
authors.initials: B
authors.lastname: Hua
authors.affiliation: Animal Health Laboratory Department of Primary Industries, Parks and Water and Environment Launceston Tas., Australia ; School of Animal & Veterinary Science, Faculty of Science, University of Adelaide Adelaide, SA, Australia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Pyecroft
authors.affiliation: Animal Health Laboratory Department of Primary Industries, Parks and Water and Environment Launceston Tas., Australia.
authors.forename: Robyn
authors.initials: R
authors.lastname: Taylor
authors.affiliation: School of Zoology, University of Tasmania Hobart, Tas., Australia.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Hamede
authors.affiliation: School of Zoology, University of Tasmania Hobart, Tas., Australia.
authors.forename: Menna
authors.initials: M
authors.lastname: Jones
authors.affiliation: Faculty of Veterinary Science, University of Sydney Sydney, NSW, Australia.
authors.forename: Katherine
authors.initials: K
authors.lastname: Belov
authors.affiliation: School of Biological Sciences, University of Wollongong Wollongong, NSW, Australia.
authors.forename: Thomas
authors.initials: T
authors.lastname: Madsen
keywords: Tasmanian Devil Facial Tumour Disease; cancer evolution; genomic decay; tetraploidy