Abstract (provisional)

Background Anopheles (Kerteszia) cruzii (Diptera: Culicidae) is a primary vector of human and simian malaria parasites in southern and southeastern Brazil. Earlier studies using chromosome inversions, isoenzymes and a number of molecular markers have suggested that An. cruzii is a species complex.

Results

In this study, a multilocus approach using six loci, three circadian clock genes and three encoding ribosomal proteins, was carried out to investigate in more detail the genetic differentiation between the An. cruzii populations from Florian?polis?Santa Catarina (southern Brazil) and Itatiaia?Rio de Janeiro States (southeastern Brazil). The analyses were performed first comparing Florian?polis and Itatiaia, and then comparing the two putative sympatric incipient species from Itatiaia (Itatiaia A and Itatiaia B). The analysis revealed high F ST values between Florian?polis and Itatiaia (considering Itatiaia A and B together) and also between the sympatric Itatiaia A and Itatiaia B, irrespective of their function. Also, using the IM program, no strong indication of migration was found between Florian?polis and Itatiaia (considering Itatiaia A and B together) using all loci together, but between Itatiaia A and Itatiaia B, the results show evidence of migration only in the direction of Itatiaia B.

Conclusions

The results of the multilocus analysis indicate that Florian?polis and Itatiaia represent different species of the An. cruzii complex that diverged around 0.6 Mya , and also that the Itatiaia sample is composed of two sympatric incipient species A and B, which diverged around 0.2 Mya . Asymmetric introgression was found between the latter two species despite strong divergence in some loci.

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