A single clonal lineage of transmissible

MARISA A YONEMITSU; RACHAEL M GIERSCH; MARIA POLO-PRIETO; MAURINE HAMMEL; FLORENCIA CREMONTE; NURIA VAZQUEZ; NICOLAS BIERNE; MICHAEL J METZGER*

eLife

eLife Sciences Publications

Año: 2019

Transmissible cancers, in which cancer cells themselves act as an infectious agent, havebeen identified in Tasmanian devils, dogs, and four bivalves. We investigated a disseminatedneoplasia affecting geographically distant populations of two species of mussels (Mytilus chilensisin South America and M. edulis in Europe). Sequencing alleles from four loci (two nuclear and twomitochondrial) provided evidence of transmissible cancer in both species. Phylogenetic analysis ofcancer-associated alleles and analysis of diagnostic SNPs showed that cancers in both species likelyarose in a third species of mussel (M. trossulus), but these cancer cells are independent from thepreviously identified transmissible cancer in M. trossulus from Canada. Unexpectedly, cancers fromM. chilensis and M. edulis are nearly identical, showing that the same cancer lineage affects both.Thus, a single transmissible cancer lineage has crossed into two new host species and has beentransferred across the Atlantic and Pacific Oceans and between the Northern and Southernhemispheres.