title: Manipulating insulin signaling to enhance mosquito reproduction.
abstract: BACKGROUND
  In the mosquito Aedes aegypti the insulin/insulin growth factor I signaling (IIS) cascade is a key regulator of many physiological processes, including reproduction. Two important reproductive events, steroidogenesis in the ovary and yolk synthesis in the fat body, are regulated by the IIS cascade in mosquitoes. The signaling molecule phosphatase and tensin homolog (PTEN) is a key inhibitor of the IIS cascade that helps modulate the activity of the IIS cascade. In Ae. aegypti, six unique splice variants of AaegPTEN were previously identified, but the role of these splice variants, particularly AaegPTEN3 and 6, were unknown.
  
  
  RESULTS
  Knockdown of AaegPTEN or its specific splice variant AaegPTEN6 (the splice variant thought to regulate reproduction in the ovary and fat body) using RNAi led to a 15-63% increase in egg production with no adverse effects on egg viability during the first reproductive cycle. Knockdown of AaegPTEN3, expressed predominantly in the head, had no effect on reproduction. We also characterized the protein expression patterns of these two splice variants during development and in various tissues during a reproductive cycle.
  
  
  CONCLUSIONS
  Previous studies in a range of organisms, including Drosophila melanogaster and Caenorhabditis elegans, have demonstrated that disruption of the IIS cascade leads to decreased reproduction or sterility. In this study we demonstrate that knockdown of the IIS inhibitor PTEN can actually increase reproduction in the mosquito, at least during the first reproductive cycle.
authors.affiliation: Department of Entomology, University of Arizona, Tucson, AZ, USA. anamj@email.arizona.edu
authors.forename: Anam J
authors.initials: AJ
authors.lastname: Arik
authors.forename: Jason L
authors.initials: JL
authors.lastname: Rasgon
authors.forename: Kendra M
authors.initials: KM
authors.lastname: Quicke
authors.forename: Michael A
authors.initials: MA
authors.lastname: Riehle
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified / Q000502:physiology*; D009033:Culicidae / Q000502:physiology*; D005260:Female; D024861:Genetic Enhancement / Q000379:methods*; D007328:Insulin / Q000235:genetics / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000378:metabolism*; D010063:Ovum / Q000254:growth & development*; D012098:Reproduction / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology
chemical_list: D007328:Insulin; D007334:Insulin-Like Growth Factor I
references.citation: Cell. 2005 Feb 25;120(4):461-72
references.pmid: 15734679
references.citation: Insect Biochem Mol Biol. 2008 Oct;38(10):932-9
references.pmid: 18718536
references.citation: Insect Biochem Mol Biol. 2007 Dec;37(12):1317-26
references.pmid: 17967350
references.citation: J Insect Physiol. 2002 May;48(5):547-554
references.pmid: 12770082
references.citation: Trends Biochem Sci. 2001 Nov;26(11):657-64
references.pmid: 11701324
references.citation: Mol Endocrinol. 2008 Sep;22(9):2128-40
references.pmid: 18606860
references.citation: Hum Mol Genet. 2004 Oct 1;13 Spec No 2:R275-88
references.pmid: 15358735
references.citation: Dev Dyn. 2005 Mar;232(3):845-54
references.pmid: 15712201
references.citation: J Biol Chem. 1998 Oct 9;273(41):26908-14
references.pmid: 9756938
references.citation: Proc Natl Acad Sci U S A. 1997 Nov 11;94(23):12479-84
references.pmid: 9356475
references.citation: Science. 2000 Oct 6;290(5489):147-50
references.pmid: 11021802
references.citation: Science. 2008 Feb 1;319(5863):611-3
references.pmid: 18239123
references.citation: J Exp Biol. 2008 Mar;211(Pt 5):741-8
references.pmid: 18281336
references.citation: Proc Natl Acad Sci U S A. 2007 Nov 27;104(48):19046-50
references.pmid: 18025456
references.citation: J Med Entomol. 2001 Jan;38(1):22-8
references.pmid: 11268686
references.citation: FEBS Lett. 2004 May 7;565(1-3):43-7
references.pmid: 15135050
references.citation: Cell Tissue Res. 2002 Jun;308(3):409-20
references.pmid: 12107434
references.citation: Am J Hum Genet. 2006 Jul;79(1):23-30
references.pmid: 16773562
references.citation: Nature. 1999 May 27;399(6734):362-6
references.pmid: 10360574
references.citation: Insect Mol Biol. 2007 Jun;16(3):277-86
references.pmid: 17433073
references.citation: Trends Endocrinol Metab. 2002 May-Jun;13(4):156-62
references.pmid: 11943559
references.citation: Annu Rev Microbiol. 2008;62:71-92
references.pmid: 18429680
references.citation: Science. 1999 Dec 24;286(5449):2521-4
references.pmid: 10617470
references.citation: Cell. 2001 Apr 20;105(2):165-8
references.pmid: 11336665
references.citation: Proc Biol Sci. 2004 Dec 7;271(1556):2523-6
references.pmid: 15590605
references.citation: Science. 2001 Apr 6;292(5514):104-6
references.pmid: 11292874
references.citation: J Med Entomol. 1975 Apr 30;12(1):92-8
references.pmid: 240028
references.citation: J Biol Chem. 2001 Dec 28;276(52):48627-30
references.pmid: 11707428
references.citation: Proc Natl Acad Sci U S A. 2008 Apr 29;105(17):6368-73
references.pmid: 18434551
references.citation: Nature. 2004 Jun 3;429(6991):562-6
references.pmid: 15175753
references.citation: Insect Biochem Mol Biol. 1999 Oct;29(10):855-60
references.pmid: 10528406
references.citation: Insect Biochem Mol Biol. 2002 Oct;32(10):1275-86
references.pmid: 12225918
references.citation: Exp Gerontol. 2001 Apr;36(4-6):869-83
references.pmid: 11295520
references.citation: J Biol Chem. 2005 Jun 10;280(23):22523-9
references.pmid: 15824124