title: Probing functional polymorphisms in the dengue vector, Aedes aegypti.
abstract: BACKGROUND
  Dengue is the most prevalent arboviral disease world-wide and its primary vector is the mosquito Aedes aegypti. The current lack of commercially-available vaccines makes control of vector populations the only effective strategy to prevent dengue transmission. Aedes aegypti geographic populations exhibit great variability in insecticide resistance and susceptibility to dengue infection. The characterization of single nucleotide polymorphisms (SNPs) as molecular markers to study quantitatively this variation is needed greatly because this species has a low abundance of microsatellite markers and limited known restriction fragments length polymorphisms (RFLPs) and single-strand conformation polymorphism (SSCP) markers.
  
  
  RESULTS
  We used RNA-seq to characterize SNPs in three Ae. aegypti strains, including the Liverpool (LVP) strain, from which the current genome annotation is derived. We identified 131,764 unique genome locations with at least one alternative nucleotide to what is reported in the reference annotation. These comprised changes in both open-reading frames (ORFs) and untranslated regions (UTRs) of transcripts. An in depth-look at sequence variation in immunity genes revealed that those associated with autophagy, MD2-like receptors and Peptidoglycan Recognition Proteins had more sequence variation in their 3'UTRs than mutations associated with non-synonymous changes. This supports the conclusion that these genes had maintained their functional specificity while being adapted to different regulatory domains. In contrast, a number of peroxidases, serpins and Clip-domain serine proteases exhibited conservation of putative UTR regulatory sequences while displaying diversification of the ORFs. Transcriptome evidence also was found for ~2500 novel transcriptional units (NTUs) not annotated in the reference genome.
  
  
  CONCLUSIONS
  The transcriptome-wide assessment of within and inter-strain polymorphisms in Ae. aegypti adds considerably to the number of molecular markers available for genetic studies in this mosquito. Additionally, data supporting NTU discovery emphasizes the need for continuous amendments of the reference genome annotation.
authors.forename: Mariangela
authors.initials: M
authors.lastname: Bonizzoni
authors.forename: Monica
authors.initials: M
authors.lastname: Britton
authors.forename: Osvaldo
authors.initials: O
authors.lastname: Marinotti
authors.forename: William Augustine
authors.initials: WA
authors.lastname: Dunn
authors.forename: Joseph
authors.initials: J
authors.lastname: Fass
authors.affiliation: Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA. aajames@uci.edu.
authors.forename: Anthony A
authors.initials: AA
authors.lastname: James
mesh_terms: D000330:Aedes / Q000235:genetics*; D000818:Animals; D003716:Dengue Virus / Q000502:physiology*; D005260:Female; D015723:Gene Library; D016678:Genome; D007303:Insect Vectors / Q000378:metabolism; D058977:Molecular Sequence Annotation; D016366:Open Reading Frames / Q000235:genetics; D020641:Polymorphism, Single Nucleotide; D017423:Sequence Analysis, RNA; D059467:Transcriptome; D020506:Untranslated Regions / Q000235:genetics
chemical_list: D020506:Untranslated Regions