title: Analysis of esterase enzyme activity in adults of the major malaria vector Anopheles funestus.
abstract: BACKGROUND
  Anopheles funestus is a major vector of malaria in sub-Saharan Africa. In order to apply effective control measures against this vector, it is necessary to understand the underlying physiological factors that play a critical role in its development, reproduction, fertility and susceptibility to insecticides. One enzyme family involved in the above mentioned biological pathways is the esterases. The aim of this study was to analyse esterase activity levels at different ages during the life-span of adult Anopheles funestus Giles in order to better understand the complex biological processes in this species.
  
  
  METHODS
  Isoenzyme electrophoresis (IEE) was used to examine the esterase activity in laboratory colonised An. funestus adults aged between 2 h (h) and 30 days post eclosion as well as in wild An. funestus adults aged between 2 h and 15 days post eclosion. Esterase activity was quantified by densitometry analysis of the IEE gels. Esterases were classified according to their activity inhibition by organic phosphates, eserine sulphate and sulphydryl reagents.
  
  
  RESULTS
  Nine esterases IEE profiles were common to both the laboratory colonised and wild An. funestus adults. These esterases were further divided into acetylesterases, arylesterases, carboxylesterases and acetylcholinesterase. The activity level of certain specific esterases was primarily influenced by age and/or gender.
  
  
  CONCLUSIONS
  The information from this study contributes towards the general understanding of esterase enzyme activity variation in adults of a major malaria vector An. funestus. This variation likely carries physiological and adaptive significance and may influence specific characteristics, such as reproductive fitness and insecticide resistance that are epidemiologically important.
authors.affiliation: Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa. yaeld@nicd.ac.za.|Centre for Opportunistic, Tropical and Hospital Infections, National Institute for Communicable Diseases, a Division of the National Health Laboratory Service, Sandringham, Johannesburg, South Africa. yaeld@nicd.ac.za.
authors.forename: Yael Leah
authors.initials: YL
authors.lastname: Dahan-Moss
authors.affiliation: Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa. lizettek@nicd.ac.za.|Centre for Opportunistic, Tropical and Hospital Infections, National Institute for Communicable Diseases, a Division of the National Health Laboratory Service, Sandringham, Johannesburg, South Africa. lizettek@nicd.ac.za.
authors.forename: Lizette Leonie
authors.initials: LL
authors.lastname: Koekemoer
mesh_terms: D000818:Animals; D000852:Anopheles / Q000201:enzymology*; D003720:Densitometry; D004586:Electrophoresis; D004791:Enzyme Inhibitors / Q000378:metabolism; D004950:Esterases / Q000032:analysis* / Q000145:classification; D007303:Insect Vectors; D007527:Isoenzymes / Q000032:analysis / Q000145:classification
chemical_list: D004791:Enzyme Inhibitors; D007527:Isoenzymes; D004950:Esterases