Structuration of Vairimorpha (Nosema) ceranae populations in the South Western Indian Ocean

Article abstract : The microsporidian Vairimorpha ceranae is one of the most common parasites of the honeybee worldwide. A single honeybee carries multiple alleles of V. ceranae genes that seem to be ubiquitous. As a consequence, nucleotide diversity analyses have not allowed discriminating genetic structuration of parasite populations yet. We performed deep loci-targeted sequencing to monitor the haplotype frequencies of genetic markers in isolates from discontinuous territories, namely the tropical islands of the South West Indian Ocean. While oceanic isolates differed from Eur-pean and Asian outgroups, parasite populations from distinct archipelagoes also differed in their haplotype distribution. Interestingly an original and very divergent Malagasy isolate was detected. The population structuration allowed formulating hypothesis upon the natural history on V. ceranae in this oceanic area.