Genetic features of bivalve transmissible neoplasia in blue mussels from the Kola Bay (Barents Sea) suggest a recent trans‐Arctic migration of the cancer lineages

• Published in: Molecular Ecology
• Main Authors: Skazina, Maria, Ponomartsev, Nikita, Maiorova, Mariia, Khaitov, Vadim, Marchenko, Julia, Lentsman, Natalia, Odintsova, Nelly, Strelkov, Petr
• Other Authors: Russian Science Foundation
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2023
• Subjects: Genetics; Ecology, Evolution, Behavior and Systematics; Arctic; Barents Sea; Pacific; Kola Bay; Northern Sea Route
• Online Access: http://dx.doi.org/10.1111/mec.17157; https://onlinelibrary.wiley.com/doi/pdf/10.1111/mec.17157

Abstract Ecology and biogeography of bivalve transmissible neoplasia (BTN) are underexplored due to its recent discovery and a challenging diagnostics. Blue mussels harbour two evolutionary lineages of BTN, Mtr BTN1 and Mtr BTN2, both derived from Mytilus trossulus . Mtr BTN1 has been found only in M. trossulus from North Pacific. Mtr BTN2 parasitizes different Mytilus spp. worldwide. BTN in M. trossulus in the Atlantic sector has never been studied. We looked for BTN in mussels from the Barents Sea using flow cytometry of cells, qPCR with primers specific to cancer‐associated alleles and sequencing of mtDNA and nuclear loci. Both Mtr BTN1 and Mtr BTN2 were present in our material, though their prevalence was low (~0.4%). All cancers parasitized M. trossulus except one, Mtr BTN1, which was found in a hybrid between M. trossulus and M. edulis . The mtDNA haplotypes found in both lineages were nearly identical to those known from the Northwest Pacific but not from elsewhere. Our results suggest that these two lineages may have arrived in the Barents Sea in recent decades with the maritime transport along the Northern Sea Route. A young evolutionary age of Mtr BTN1 seems to indicate that it is an emerging disease in the process of niche expansion. Comparing the new and the published sequence data on tumour suppressor p53, we proved that the prevalence of BTN in mussels can reach epizootic levels. The finding of diverse recombinants between paternally and maternally inherited mtDNAs in somatic tissues of M. trossulus was an unexpected result of our study.