Identification of cross-species microRNA-based Communication in Brugia malayi with its endosymbiont Wolbachia

Brugia malayi is a parasitic nematode that causes lymphatic filariasis in humans. A total of 178 novel microRNA were identified from short read transcriptional data, which when combined with known Brugia microRNAs yielded a total of 284 microRNA. Of these, 123 microRNA sequences (43%) are differentially expressed over the mammalian life stages of B. malayi that we examined. Putative targets of these microRNA were identified from inversely expressed target clusters that contain valid seed sequences for the corresponding microRNAs. The largest identified cluster is downregulated in adult females and enriched in zinc finger domains, helicase domains, and DNA binding domains suggesting this microRNA cluster may have regulatory control over a large proportion of adult female specific mRNA genes. MicroRNA-like molecules are identified as produced by the Wolbachia endosymbiont, providing evidence for direct nucleic acid-based interdomain communication between filarial nematodes and their bacterial obligate endosymbiont. Examination of microRNA expression over the life cycle of the filarial nematode Brugia malayi.