The Glossina proteolytic lectin (Gpl) gene is expressed only in members of Glossina species

Differentiation of bloodstream-form trypanosomes into procyclics in tsetse flies (Diptera: Glossinidae) is a crucial step in the establishment of midgut infections. A number of factors have been implicated in the transformation process, including enzymes and lectins or lectin-like molecules. Recently, Glossina proteolytic lectin (Gpl) gene, which encodes a protein with both lectin and trypsin activities has been shown to stimulate transformation of bloodstream-form trypanosomes into procyclics in vitro. Using RT-PCR, we show that the induction of Gpl gene expression by blood meal occurs only in Glossina fuscipes fuscipes Newstead, Glossina austeni Newstead, Glossina pallidipes Austen, and not in the Anopheles gambiae Giles sensu stricto, Phlebotomus duboscqi Neveu-Lemaire, Rhipicephalus appendiculatus Neumann and Stomoxys calcitrans (Linnaeus). The expression means of Gpl mRNA in G. f. fuscipes following a blood meal were significant (P