Identification and characterization of a putative sevenless homologue in the malaria vector Anopheles gambiae

Tyrosine kinase sequences were identified and characterized in Anopheles ga mbiae, the major vector of malaria in subsaharan Africa. One of these seque nces has the characteristics expected for a homologue of the Drosophila sev enless gene, which is necessary for R7 photoreceptor cell fate determinatio n in the developing compound eye. The putative Anopheles sevenless gene hom ologue is located in a telomeric region of the X chromosome and is expresse d in the head of late larval and pupal stage mosquitoes. Identification of the Anopheles homologue of the sevenless gene is a first step towards the d evelopment of a dominant phenotypic marker that could be used for detecting transformed Anopheles mosquitoes in a wide variety of genetic backgrounds and, as such, could be used in the development of transgenic mosquitoes for the control of parasite transmission. Preliminary evidence for sevenless s equences were also found in DNA from blackfly, Mediterranean fruit fly and the honeybee.