Paris (AFP)
An infectious cancer has spread to two different species of mussels on both sides of the Atlantic Ocean, according to a study that points to shipping as a vector of the disease.
Cancers are rarely contagious but it happens. "The Tasmanian devil, dogs and bivalves have all developed cancers that can spread from one individual to another, acting more like a pathogen or parasite," says Marisa Yonemitsu of the Pacific Northwest Research Institute in Seattle , co-author of the study published in the scientific journal eLife.
One of these cancers, called neoplasia or molluscan leukemia, has been detected in Mytilus trossulus, mussels from British Columbia, Canada.
But also in M. edulis in France and the Netherlands and in M. chilensis along the coasts of Chile and Argentina.
By analyzing the DNA of the different cancer cells, Marisa Yonemitsu and her team discovered that "those taken in mussels from Europe and South America were genetically almost identical, suggesting that they had a common origin".
The common "ancestor" of these contagious cancers is "probably a single mold (M. trossulus) infected in the past by a primary form of the disease," a statement said.
But since British Columbia mussels, M. trossulus, are not present in equatorial areas, Michael Metzger, also of the Pacific Northwest Research Institute and co-author of the study, believes that infected molluscs "were accidentally transported on an international shipping vessel ".
"Our study shows that infectious bivalve cancers are very common pathogens and that humans may be responsible for introducing them to new vulnerable species," Metzger concludes.
© 2019 AFP