Expression and function of the Drosophila melanogaster ADH in male Ceratitis capitata adults: a potential strategy for medfly genetic sexing based ongene-transfer technology

The aim of development of a Mediterranean fruit fly Ceratitis capitata gene tic sexing strain derives from the large scale SIT programmes being carried out to control this pest. Toward this direction, we present here the male- specific expression of the Drosophila melanogaster alcohol dehydrogenase (A DH) in medfly transgenic adults generated by Minos-mediated germ line trans formation. This expression pattern is obtained by using a promoter fragment of the male-specific gene MSSP-alpha2 of the medfly. We show that the hete rologous enzyme is functional in the medfly oxidizing both ethanol and 2-pr opanol. Although leading to an approximately twofold increase of total ADH activity in male compared to female transgenic adults, these expression lev els are not enough for performing genetic sexing when high doses of environ mental alcohol are applied. This could be achieved either by further enhanc ement of the transgene expression or by generating an Adh(-) line to host t he Minos insertions.