Tsetse flies: Genetics, evolution, and role as vectors

Tsetse flies (Diptera: Glossinidae) are an ancient taxon of one genus, Glossina, and limited species diversity. All are exclusively haematophagous and Confined to sub-Saharan Africa. The Glossina are the principal vectors of African trypanosomes Tryponosoma sp. (Kinetoplastida: Trypanosomatidae) and as such, are of great medical and economic importance. Clearly tsetse flies and trypanosomes are coadapted and evolutionary interactions between them are manifest. Numerous clonally reproducing strains of Trypanosoma sp. exist and their genetic diversities and spatial distributions are in a inadequately known. Here I review the breeding structures of the principle trypanosome vectors, G. morsitans s.l., G. pallidipes, G. palpalis s.l. and G. fuscipes fuscipes. All show highly structured populations among which there is Surprisingly little detectable gone flow. Rather less is known of the breeding structure of T brucei seosulato vis a vis their vector tsetse flies but many genetically differentiated Strains exist in nature. Genetic recombination in Tryponosoma via meiosis has recently been demonstrated in the laboratory thereby furnishing a mechanism of strain differentiation in addition to that of simple mutation. Spatially and genetically representative sampling of both trypanosome species and strains and their Glossina vectors is a major barrier to a comprehensive understanding of their mutual relationships. (c) 2008 Elsevier B.V. All rights reserved.