Genetic structuring and fixed polymorphisms in the gene period among natural populations of Lutzomyia longipalpis in Brazil

Abstract

BackgroundEven one hundred years after being originally identified, aspects of the taxonomy of the sand fly Lutzomyia longipalpis, the principal vector of Leishmania infantum in the Americas, remain unresolved for Brazilian populations of this vector. The diversity of morphological, behavioral, biochemical, and ethological characters, as well as the genetic variability detected by molecular markers are indicative of the presence of a complex of species.MethodsIn this study, a 525 bp fragment of the period gene was used to evaluate sympatric populations of L. longipalpis. A combination of probabilistic methods such as maximum likelihood and genetic assignment approach to investigate sympatric species of L. longipalpis were applied in three populations of Northeast Brazil.ResultsFixed polymorphisms in geographically isolated populations of L. longipalpis from two localities in the state of Ceará and one in the state of Pernambuco, Brazil, was identified in a 525 bp fragment of the gene period (per). Our results suggest a direct relationship between the number of spots found in males’ tergites and the genetic variation in cryptic species of L. longipalpis. The fragment used in this study revealed the nature of the ancestral morphotype 1S.ConclusionNew polymorphisms were identified in the gene per which can be used as a genetic barcode to sympatric taxonomy of L. longipalpis. The per gene fragment confirmed the presence of two siblings species of L. longipalpis in Sobral and showed that these same species are present in two other localities, representing an expansion within the L. longipalpis species complex with regards to the states of Ceará and Pernambuco.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-015-0785-6) contains supplementary material, which is available to authorized users.

The Lutzomyia longipalpis complex: a brief natural history of aggregation-sex pheromone communication

“…Differential rates of evolution among genes, maintenance of ancestral polymorphisms and introgression are factors that describe discordant evolutionary history, especially for very closely related species such as L. longipalpis complex [59]. Microsatellites and nuclear genes associated with sexual behavior in Drosophila such as cacophony , paralytic and period ( per ) genes are among the markers that have proven useful for identifying clusters of putative species [47, 48, 51, 52, 57, 58, 60–63]. …”

The current status of the Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae) species complex

“…Incongruent evidence shown by some molecular markers (e.g., variable levels of divergence and phylogenetic relationships) could be due to different rates of evolution, introgression between counterparts, or the relative brief time of divergence among members of this species complex, and could explain the conflicting interpretations among early studies of Brazilian populations. For example, the per gene was considered a useful molecular marker in studies of population genetics, and even more so considering the additional evidence from pheromones and copulation song analysis ( Bauzer et al 2002a , b , Araki et al 2009 ) and the fixed polymorphisms detected in nearby populations in Northeast Brazil ( Lima-Costa Jr et al. 2015 ).…”

GENETIC DIVERSITY OF Lutzomyia (Nyssomyia) intermedia IN AN ENDEMIC AREA OF AMERICAN CUTANEOUS LEISHMANIASIS, STATE OF PARANÁ, BRAZIL

“…This is contrasting to the study by Silva et al (2011), who analyzed populations of Lutozmyia (Lutzomyia) longipalpis (Lutz and Neiva, 1912) in the state of Maranhão, northeastern Brazil, using RAPD, and divided the population according to the morphological markers found in males that they used to distinguish the existing varieties within this species. In the case of L. longipalpis, the possible existence of a species complex based on the morphological markers present in males has been justified by several genetic and behavioral studies (Souza et al, 2004b;Lima Costa et al, 2015;Vigoder et al, 2015;Souza et al, 2017).…”