Revista de biología vectorial

Genetic Structure of Sympatric Populations of Female Lutzomyia Longipalpis (Diptera: Psychodidae) In Sobral and Caririaçu, Ceará State, Brazil

Moises Thiago de Souza Freitas*, César Raimundo Lima Costa Jr, Lidiane Gomes da Silva, Tereza Cristina Leal- Balbino, Reginaldo Peçanha Brazil and Valdir de Queiroz Balbino

Objectives: Accurate identification of these insects is critical to avoiding mistakes in the recognition of vector and non-vector species, so the invariant phenotypic patterns displayed by the females of L. longipalpis require the implementation of molecular methods of identification. Our goal was to examine genetic variation in the females of L. longipalpis using the SNPs reported in the males of this vector species.

Methods: We trapped sand flies near houses and domestic animal shelters at two localities in the state of Ceará, Brazil, using two to five CDC miniature light traps. Genomic DNA was separately extracted from each female using 100 μl of Chelex resin, and a 525 bp fragment of the period gene was used to assess genetic polymorphism in the two geographically isolated populations.

Results: The results indicate the presence of three fixed polymorphisms (T124C, C171T, and C424T) within this gene. Genetic structure analysis indicated that the studied L. longipalpis populations can be divided into two main subgroups (1S-like and 2S-like), with the ad hoc quantity supporting the number K = 2.

Conclusion: Collectively, our results suggest a direct relationship between the number of spots found in the males’ tergites and the genetic variation observed in the L. longipalpis females in the state of Ceará. The SNPs observed in the period gene will be useful for future studies of molecular eco-epidemiology in areas where these species occur in sympatry.