The Anopheles gambiae alpha-tubulin-1b promoter directs neuronal, testes and developing imaginal tissue specific expression and is a sensitive enhancer detector

A knowledge gap in mosquito functional genetic analysis is the dearth of characterized regulatory regions that can target tissue specific transgene expression. To broaden the tools available, a promoter region of the Anopheles gambiae a-tubulin1b gene has been assayed following fusion to the green fluorescent protein (GFP) reporter gene and stable transformation of An. gambiae. In eight transgenic lines,

the Angtub a1b regulatory region directed a core profile of tissue specific expression in the head, chordotonal organs, ventral nerve cord and testes. This profile overlaps those seen for a2-tubulin expression in Drosophila melanogaster and Bombyx mori. In addition, widespread position dependant expression was observed in other specific tissues that were unique to each line. For example, in different lines, expression was observed in larval and adult muscles, fatbody, cuticle and midgut secretory cells. The majority of

genomic transgene insertions were mapped to within 10 kb of a gene, suggesting that the Angtub a1b basal promoter is particularly sensitive to enhancers and may be suitable to form the basis of a sensitive enhancer trapping construct, in combination with a binary expression system such as Gal4-UAS.