Molecular taxonomy of the two Leishmania vectors Lutzomyia umbratilis and Lutzomyia anduzei (Diptera: Psychodidae) from the Brazilian Amazon

Abstract

BackgroundLutzomyia umbratilis (a probable species complex) is the main vector of Leishmania guyanensis in the northern region of Brazil. Lutzomyia anduzei has been implicated as a secondary vector of this parasite. These species are closely related and exhibit high morphological similarity in the adult stage; therefore, they have been wrongly identified, both in the past and in the present. This shows the need for employing integrated taxonomy.MethodsWith the aim of gathering information on the molecular taxonomy and evolutionary relationships of these two vectors, 118 sequences of 663 base pairs (barcode region of the mitochondrial DNA cytochrome oxidase I – COI) were generated from 72 L. umbratilis and 46 L. anduzei individuals captured, respectively, in six and five localities of the Brazilian Amazon. The efficiency of the barcode region to differentiate the L. umbratilis lineages I and II was also evaluated. The data were analyzed using the pairwise genetic distances matrix and the Neighbor-Joining (NJ) tree, both based on the Kimura Two Parameter (K2P) evolutionary model.ResultsThe analyses resulted in 67 haplotypes: 32 for L. umbratilis and 35 for L. anduzei. The mean intra-specific genetic distance was 0.008 (0.002 to 0.010 for L. umbratilis; 0.008 to 0.014 for L. anduzei), whereas the mean interspecific genetic distance was 0.044 (0.041 to 0.046), supporting the barcoding gap. Between the L. umbratilis lineages I and II, it was 0.009 to 0.010. The NJ tree analysis strongly supported monophyletic clades for both L. umbratilis and L. anduzei, whereas the L. umbratilis lineages I and II formed two poorly supported monophyletic subclades.ConclusionsThe barcode region clearly separated the two species and may therefore constitute a valuable tool in the identification of the sand fly vectors of Leishmania in endemic leishmaniasis areas. However, the barcode region had not enough power to separate the two lineages of L. umbratilis, likely reflecting incipient species that have not yet reached the status of distinct species.

A phylogeny of sand flies (Diptera: Psychodidae: Phlebotominae), using recent Ethiopian collections and a broad selection of publicly available DNA sequence data

“…Phlebotomine DNA sequence data are increasingly common, although they are usually restricted to particular species or species groups (Di Muccio et al, 2000;Soto et al, 2001;Depaquit et al, , 2008Aransay et al, 2003;Mazzoni et al, 2008;Franco et al, 2010;Scarpassa & Alencar, 2013) or regions (Di Muccio et al, 2000;Aransay et al, 2003;Lins et al, 2008;Franco et al, 2010;Gutiérrez et al, 2014) and are often focused on population genetics (Soto et al, 2001;Depaquit et al, 2008) or the identification of informative markers (Peixoto et al, 2001;Lins et al, 2008). Most importantly, it is rare for individual specimens to be sequenced for multiple markers.…”

Genetic diversity and population structure in the Leishmania guyanensis vector Lutzomyia anduzei (Diptera, Psychodidae) from the Brazilian Amazon

“…In contrast, the fragment at the 3 0 end of this gene 155 has demonstrated to be highly variable at the intra-specific level 156 and has therefore been a useful marker in studies on the genetic 157 diversity, population structure and phylogeographic studies of a 158 great number of insect species, including anophelines (Scarpassa 159 and Conn, 2006;revision in Loaiza et al, 2011) and sandflies 160 (Arrivillaga et al, 2002;Scarpassa and Alencar, 2012). Unlike COI, (1) Novo Airão, Amazonas 2°47 0 S; 60°55 0 W 23 H25(2), H26 (6) Table 3 also shows the average number of nucleotide differ- the Barcode region in this species (Scarpassa and Alencar, 2013). 398 Comparing these results with those obtained for L. umbratilis, using and São Gabriel da Cachoeira (both loci: P < 0.001), which suggests 420 population expansion.…”

Speciation in the Leishmania guyanensis Vector Lutzomyia umbratilis (Diptera: Psychodidae) from Northern Brazil — Implications for Epidemiology and Vector Control

“…In fact, most of L. anduzei specimens found to be naturally infected with Leishmania before this date (1977) could actually be L. umbratilis. After this date, it has been possible distinguish L. umbratilis and L. anduzei morphologically, based on the internal and external genitalia of males and females [2,70]. Currently, they can also be identified molecularly by using DNA barcode sequences from COI of mitochondrial DNA [70].…”

“…After this date, it has been possible distinguish L. umbratilis and L. anduzei morphologically, based on the internal and external genitalia of males and females [2,70]. Currently, they can also be identified molecularly by using DNA barcode sequences from COI of mitochondrial DNA [70]. The phylogenetic analysis of this dataset found two strongly supported monophyletic clades, although the genetic distances between them, based on the Kimura 2 Parameters (K2P) model, were very small (4.4%), suggesting that these species are very closely related (sister species) [70].…”