title: Culex tarsalis vitellogenin gene promoters investigated in silico and in vivo using transgenic Drosophila melanogaster.
abstract: BACKGROUND
  Genetic modification, or transgenesis, is a powerful technique to investigate the molecular interactions between vector-borne pathogens and their arthropod hosts, as well as a potential novel approach for vector-borne disease control. Transgenesis requires the use of specific regulatory regions, or promoters, to drive expression of genes of interest in desired target tissues. In mosquitoes, the vast majority of described promoters are from Anopheles and Aedes mosquitoes.
  
  
  RESULTS
  Culex tarsalis is one of the most important vectors of arboviruses (including West Nile virus) in North America, yet it has not been the subject of molecular genetic study. In order to facilitate molecular genetic work in this important vector species, we isolated four fat body-specific promoter sequences located upstream of the Cx. tarsalis vitellogenin genes (Vg1a, Vg1b, Vg2a and Vg2b). Sequences were analyzed in silico to identify requisite cis-acting elements. The ability for promoter sequences to drive expression of green fluorescent protein (GFP) in vivo was investigated using transgenic Drosophila melanogaster. All four promoters were able to drive GFP expression but there was dramatic variation between promoters and between individual Drosophila lines, indicating significant position effects. The highest expression was observed in line Vg2bL3, which was >300-fold higher than the lowest line Vg1aL2.
  
  
  CONCLUSIONS
  These new promoters will be useful for driving expression of genes of interest in transgenic Cx. tarsalis and perhaps other insects.
authors.affiliation: The W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America.
authors.forename: Song
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Entomology, The Center for Infectious Disease Dynamics and the Huck Institutes of The Life Sciences, Millennium Science Complex, The Pennsylvania State University, University Park, Pennsylvania, United States of America.
authors.forename: Jason L
authors.initials: JL
authors.lastname: Rasgon
mesh_terms: D000330:Aedes / Q000235:genetics; D000818:Animals; D030801:Animals, Genetically Modified / Q000235:genetics; D000852:Anopheles / Q000235:genetics; D003465:Culex / Q000235:genetics*; D009033:Culicidae / Q000235:genetics; D004331:Drosophila melanogaster / Q000821:virology*; D049452:Green Fluorescent Proteins / Q000235:genetics; D007303:Insect Vectors / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics*; D014819:Vitellogenins / Q000235:genetics*; D014901:West Nile Fever / Q000821:virology; D014902:West Nile virus / Q000235:genetics
chemical_list: D014819:Vitellogenins; D049452:Green Fluorescent Proteins