Extensive mobilome heterogeneity in a widespread endosymbiont: A candidate dimeric plasmid and highly fragmented prophages in Wolbachia from Culex pipiens.

A near-complete Wolbachia genome and its mobilome were resolved from single ovaries of Culex pipiens molestus, revealing a new dimeric pWCP plasmid structure and fragmented WO prophages.

• Why it matters: Repeat-rich mobile elements in Wolbachia are hard to assemble, leaving gaps in how prophages and plasmids evolve and diversify in mosquito vectors.
• What they did: Using an Oxford Nanopore long-read strategy without PCR amplification on single-dissected female ovaries, the team sequenced native long-read molecules and validated candidate mutations with additional short reads.
• The result: They found a new dimeric pWCP plasmid suggesting multimeric plasmid forms linked to active replication, and extensive WO fragmentation with multiple alternative gene syntenies, indicating heterogeneous prophage architectures in Wolbachia (wPip) group strains.