title: Characterisation of novel microRNAs in the Black flying fox (Pteropus alecto) by deep sequencing.
abstract: BACKGROUND
  Bats are a major source of new and emerging viral diseases. Despite the fact that bats carry and shed highly pathogenic viruses including Ebola, Nipah and SARS, they rarely display clinical symptoms of infection. Host factors influencing viral replication are poorly understood in bats and are likely to include both pre- and post-transcriptional regulatory mechanisms. MicroRNAs are a major mechanism of post-transcriptional gene regulation, however very little is known about them in bats.
  
  
  RESULTS
  This study describes 399 microRNAs identified by deep sequencing of small RNA isolated from tissues of the Black flying fox, Pteropus alecto, a confirmed natural reservoir of the human pathogens Hendra virus and Australian bat lyssavirus. Of the microRNAs identified, more than 100 are unique amongst vertebrates, including a subset containing mutations in critical seed regions. Clusters of rapidly-evolving microRNAs were identified, as well as microRNAs predicted to target genes involved in antiviral immunity, the DNA damage response, apoptosis and autophagy. Closer inspection of the predicted targets for several highly supported novel miRNA candidates suggests putative roles in host-virus interaction.
  
  
  CONCLUSIONS
  MicroRNAs are likely to play major roles in regulating virus-host interaction in bats, via dampening of inflammatory responses (limiting the effects of immunopathology), and directly limiting the extent of viral replication, either through restricting the availability of essential factors or by controlling apoptosis. Characterisation of the bat microRNA repertoire is an essential step towards understanding transcriptional regulation during viral infection, and will assist in the identification of mechanisms that enable bats to act as natural virus reservoirs. This in turn will facilitate the development of antiviral strategies for use in humans and other species.
authors.affiliation: CSIRO Australian Animal Health Laboratory, 5 Portarlington Rd, Geelong East, Victoria 3220, Australia. chris.cowled@csiro.au.
authors.forename: Christopher
authors.initials: C
authors.lastname: Cowled
authors.forename: Cameron R
authors.initials: CR
authors.lastname: Stewart
authors.forename: Vladimir A
authors.initials: VA
authors.lastname: Likic
authors.forename: Marc R
authors.initials: MR
authors.lastname: Friedländer
authors.forename: Mary
authors.initials: M
authors.lastname: Tachedjian
authors.forename: Kristie A
authors.initials: KA
authors.lastname: Jenkins
authors.forename: Mark L
authors.initials: ML
authors.lastname: Tizard
authors.forename: Pauline
authors.initials: P
authors.lastname: Cottee
authors.forename: Glenn A
authors.initials: GA
authors.lastname: Marsh
authors.forename: Peng
authors.initials: P
authors.lastname: Zhou
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Baker
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Bean
authors.forename: Lin-fa
authors.initials: LF
authors.lastname: Wang
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002685:Chiroptera / Q000235:genetics*; D063990:Gene Ontology; D059014:High-Throughput Nucleotide Sequencing; D007438:Introns; D055029:Inverted Repeat Sequences; D008297:Male; D035683:MicroRNAs / Q000235:genetics*; D058977:Molecular Sequence Annotation; D008969:Molecular Sequence Data; D005810:Multigene Family; D034622:RNA Interference; D017423:Sequence Analysis, RNA; D012689:Sequence Homology, Nucleic Acid
chemical_list: D035683:MicroRNAs