1 September 2009 Origins and Evolution of a Transmissible Cancer
Clare A. Rebbeck, Rachael Thomas, Matthew Breen, Armand M. Leroi, Austin Burt
Author Affiliations +

Canine transmissible venereal tumor (CTVT) is an infectious disease of dogs. Remarkably, the infectious agent is the cancerous cell itself. To investigate its origin and spread, we collected 37 tumor samples from four continents and determined their evolutionary relationships using microsatellite length differences and microarray-based comparative genomic hybridization (aCGH). The different tumors show very little microsatellite variation, and the pattern of variation that does exist is consistent with a purely asexual mode of transmission. Approximately one quarter of the loci scored by aCGH show copy number variation relative to normal dogs, again with little variation among different tumor samples. Sequence analysis of the RPPH1 gene indicates an origin from either dogs or wolves, and microsatellite analysis indicates that the tumor is more than 6000 years old, and perhaps originated when dogs were first domesticated. By contrast, the common ancestor of extant tumors lived within the last few hundred years, long after the first tumor. The genetic and genomic patterns we observe are typical of those expected of asexual pathogens, and the extended time since first origin may explain the many remarkable adaptations that have enabled this mammalian cell lineage to live as a unicellular pathogen.

© 2009 The Society for the Study of Evolution.
Clare A. Rebbeck, Rachael Thomas, Matthew Breen, Armand M. Leroi, and Austin Burt "Origins and Evolution of a Transmissible Cancer," Evolution 63(9), 2340-2349, (1 September 2009). https://doi.org/10.1111/j.1558-5646.2009.00724.x
Received: 21 January 2009; Accepted: 1 April 2009; Published: 1 September 2009

This article is only available to subscribers.
It is not available for individual sale.

chromosomal evolution
evolutionary genomics
genetic variation
molecular evolution
population genetics
Get copyright permission
Back to Top