Phylogeography and genetic variability of populations of Lutzomyia longipalpis (Diptera: Psychodidae) inferred from ND4 gene.

PECH-MAY A; RAMSEY J; LIOTTA D; GIULIANI M; BERROZPE P; QUINTANA MG; SALOMÓN OD

Reims

Simposio; IX International Symposium on Phlebotominae Sandflies; 2016

Lutzomyia longipalpis is the most important vector in the transmission of Leishmania infantum in the Americas; it is widelydistributed from southern Mexico to northern Argentina. This species is actually a complex of at least four sister species.In Argentina, it is distributed in the provinces of Misiones, Formosa, Corrientes, Entre Ríos and Salta. We report here the preliminary analysis of phylogeography and genetic variability of Argentinian populations of Lutzomyia longipalpis inferred from theND4 gene. For the phylogeographic analysis, we used Genbank sequences of the mitochondrial ND4 gene from Brazil, Colombia,Venezuela, Honduras, Costa Rica, and Guatemala, in addition to our 73 sequences from Argentina: Clorinda (Clo), Corrientes(Corr), Puerto Iguazú (Ig), San Ignacio (SI), Santo Tome (ST) and Tartagal (Tar). Phylogenetic analysis indicates that Lu. longipalpis populations from Argentina divide into two clades, (1) Corr, ST, Clo, Ig, Tar and SI; (2) Tar, ST and SI. These two cladeswere separated from Colombian, Venezuelan, Honduran, Costa Rican, and Guatemalan populations. The second Argentinian cladewas grouped with populations from Jacobina and Lapinha in Brazil. In terms of Inter-population genetic diversity, 68 polymorphicsites were determined and 35 haplotypes were identified, with a range of 4?14 haplotypes per population. Haplotype diversity was high Hd = 0.858 ± 0.039, while nucleotide diversity and nucleotide polymorphism were low (p = 0.014 ± 0.001 andh = 0.022 ± 0.002, respectively). Neutrality tests were not significant for population expansion. ST and Tar had the highest geneticdiversity among the six populations, while Ig and Corr had the lowest. Population expansion was found in Corr and Ig, while STand Tar had population subdivisions. The population structure of Lu. longipalpis with the ND4 fragment showed high geneticdifferentiation among Argentina populations (Fst = 0.452, p < 0.0001). High genetic differentiation was observed between SIand Corr populations (Fst = 0.86, p < 0.0001), with a genetic distance of 0.017 ± 0.004. According to these preliminary results,divergence patterns may be associated with climatic and physiographic discontinuities. In order to understand better dispersalroutes and clades involved in Argentinian populations, samples from the neighboring countries Bolivia, Paraguay, Uruguay andmore samples of Brazil will be analyzed.