ABSTRACT
Studies based on the bacterial diversity present in Mansonia spp. are limited; therefore, the aim of this study was to investigate the bacterial diversity in females and larvae of Mansonia spp., describe the differences between the groups identified, and compare the microbiota of larvae from different collection sites. Sequences of the 16S rRNA region from the larvae and females of Mansonia spp. were analyzed. Diversity analyzes were performed to verify the possible bacterial differences between the groups and the collection sites. The results showed Pseudomonas was the most abundant genus in both females and larvae, followed by Wolbachia in females and Rikenellaceae and Desulfovibrio in larvae. Desulfovibrio and Sulfurospirillum, sulfate- and sulfur-reducing bacteria, respectively, were abundant on the larvae. Aminomonas, an amino acid-degrading bacterium, was found only in larvae, whereas Rickettsia was identified in females. Bacterial diversity was observed between females and larvae of Mansonia and between larvae from different collection sites. In addition, the results suggest that the environment influenced bacterial diversity.
Subject(s)
Culicidae , Female , Animals , Larva/microbiology , Brazil , RNA, Ribosomal, 16S/genetics , Culicidae/genetics , Bacteria/geneticsABSTRACT
Here, the main goal is to assess natural infections of Plasmodium spp. in anophelines in a forest reserve from the same region where we previously found a surprisingly high rate (5.2%) of plasmodia infections (n = 25) in Kerteszia mosquitoes (N = 480) on the slopes of Serra do Mar, Atlantic Forest, Brazil. The mosquito collection sampling was carried out at the Legado das Águas Forest Reserve using CDC light traps and Shannon traps at night (5-10 pm) in 3-day collections in November 2021 and March, April, May, and November 2022. The captured specimens were morphologically identified at the species level and had their genomic DNA extracted in pools of up to 10 mosquitoes/pool. Each pool was tested using 18S qPCR and cytb nested PCR plus sequencing. A total of 5301 mosquitoes, mostly belonging to the genus Kerteszia (99.7%), were sampled and sorted into 773 pools. Eight pools positive for Plasmodium spp. were identified: four for Plasmodium spp., one for P. vivax or P. simium, one for P. malariae or P. brasilianum, and two for the P. falciparum-like parasite. After Sanger sequencing, two results were further confirmed: P. vivax or P. simium and P. malariae or P. brasilianum. The minimum infection rate for Kerteszia mosquitoes was 0.15% (eight positive pools/5285 Kerteszia mosquitoes). The study reveals a lower-than-expected natural infection rate (expected = 5.2% vs. observed = 0.15%). This low rate relates to the absence of Alouatta monkeys as the main simian malaria reservoir in the studied region. Their absence was due to a significant population decline following the reemergence of yellow fever virus outbreaks in the Atlantic Forest from 2016 to 2019. However, this also indicates the existence of alternative reservoirs to infect Kerteszia mosquitoes. The found zoonotic species of Plasmodium, including the P. falciparum-like parasite, may represent a simian malaria risk and thus a challenge for malaria elimination in Brazil.
ABSTRACT
Mosquitoes (Diptera: Culicidae) are found widely throughout the world. Several species can transmit pathogens to humans and other vertebrates. Mosquitoes harbor great amounts of bacteria, fungi, and viruses. The bacterial composition of the microbiota of these invertebrates is associated with several factors, such as larval habitat, environment, and species. Yet little is known about bacterial interaction networks in mosquitoes. This study investigates the bacterial communities of eight species of Culicidae collected in Vale do Ribeira (Southeastern São Paulo State) and verifies the bacterial interaction network in these species. Sequences of the 16S rRNA region from 111 mosquito samples were analyzed. Bacterial interaction networks were generated from Spearman correlation values. Proteobacteria was the predominant phylum in all species. Wolbachia was the predominant genus in Haemagogus leucocelaenus. Aedes scapularis, Aedes serratus, Psorophora ferox, and Haemagogus capricornii were the species that showed a greater number of bacterial interactions. Bacterial positive interactions were found in all mosquito species, whereas negative correlations were observed in Hg. leucocelaenus, Ae. scapularis, Ae. serratus, Ps. ferox, and Hg. capricornii. All bacterial interactions with Asaia and Wolbachia were negative in Aedes mosquitoes.
Subject(s)
Culicidae , Mercury , Microbiota , Wolbachia , Humans , Animals , RNA, Ribosomal, 16S/genetics , Brazil , Culicidae/genetics , Bacteria/genetics , Wolbachia/genetics , Microbiota/geneticsABSTRACT
INTRODUCTION: Mosquitoes (Diptera: Culicidae) are vectors that transmit numerous pathogens to humans and other vertebrates. Haemagogus leucocelaenus is a mosquito associated with transmission of yellow fever virus. The insect gut harbors a variety of microorganisms that can live and multiply within it, thus contributing to digestion, nutrition, and development of its host. The composition of bacterial communities in mosquitoes can be influenced by both biotic and abiotic factors. The goal of this study was to investigate the bacterial diversity of Hg. leucocelaenus and verify the differences between the bacterial communities in Hg. leucocelaenus from three different locations in the Atlantic tropical rain forest and southeastern state of São Paulo State, Brazil. RESULTS: The phylum Proteobacteria was found in mosquitoes collected from the three selected study sites. More than 50% of the contigs belong to Wolbachia, followed by 5% Swaminathania, and 3% Acinetobacter. The genus Serratia was found in samples from two locations. CONCLUSIONS: Wolbachia was reported for the first time in this species and may indicates that the vector competence of the populations of the species can vary along its geographical distribution area. The presence of Serratia might facilitate viral invasion caused by the disruption of the midgut barrier via action of the SmEnhancin protein, which digests the mucins present in the intestinal epithelium.
Subject(s)
Culicidae , Mercury , Yellow Fever , Animals , Brazil , Humans , Mosquito VectorsABSTRACT
Identifying the species of the subfamily Anophelinae that are Plasmodium vectors is important to vector and malaria control. Despite the increase in cases, vector mosquitoes remain poorly known in Brazilian indigenous communities. This study explores Anophelinae mosquito diversity in the following areas: (1) a Yanomami reserve in the northwestern Amazon Brazil biome and (2) the Pantanal biome in southwestern Brazil. This is carried out by analyzing cytochrome c oxidase (COI) gene data using Refined Single Linkage (RESL), Assemble Species by Automatic Partitioning (ASAP), and tree-based multi-rate Poisson tree processes (mPTP) as species delimitation approaches. A total of 216 specimens collected from the Yanomami and Pantanal regions were sequenced and combined with 547 reference sequences for species delimitation analyses. The mPTP analysis for all sequences resulted in the delimitation of 45 species groups, while the ASAP analysis provided the partition of 48 groups. RESL analysis resulted in 63 operational taxonomic units (OTUs). This study expands our scant knowledge of anopheline species in the Yanomami and Pantanal regions. At least 18 species of Anophelinae mosquitoes were found in these study areas. Additional studies are now required to determine the species that transmit Plasmodium spp. in these regions.
Subject(s)
Anopheles/genetics , Mosquito Vectors/genetics , Plasmodium/parasitology , Animals , Brazil/epidemiology , Disease Vectors , Malaria/transmission , Mosquito Vectors/metabolism , Plasmodium/genetics , Species SpecificityABSTRACT
BACKGROUND: Environmental disturbance, deforestation and socioeconomic factors all affect malaria incidence in tropical and subtropical endemic areas. Deforestation is the major driver of habitat loss and fragmentation, which frequently leads to shifts in the composition, abundance and spatial distribution of vector species. The goals of the present study were to: (i) identify anophelines found naturally infected with Plasmodium; (ii) measure the effects of landscape on the number of Nyssorhynchus darlingi, presence of Plasmodium-infected Anophelinae, human biting rate (HBR) and malaria cases; and (iii) determine the frequency and peak biting time of Plasmodium-infected mosquitoes and Ny. darlingi. METHODS: Anopheline mosquitoes were collected in peridomestic and forest edge habitats in seven municipalities in four Amazon Brazilian states. Females were identified to species and tested for Plasmodium by real-time PCR. Negative binomial regression was used to measure any association between deforestation and number of Ny. darlingi, number of Plasmodium-infected Anophelinae, HBR and malaria. Peak biting time of Ny. darlingi and Plasmodium-infected Anophelinae were determined in the 12-h collections. Binomial logistic regression measured the association between presence of Plasmodium-infected Anophelinae and landscape metrics and malaria cases. RESULTS: Ninety-one females of Ny. darlingi, Ny. rangeli, Ny. benarrochi B and Ny. konderi B were found to be infected with Plasmodium. Analysis showed that the number of malaria cases and the number of Plasmodium-infected Anophelinae were more prevalent in sites with higher edge density and intermediate forest cover (30-70%). The distance of the drainage network to a dwelling was inversely correlated to malaria risk. The peak biting time of Plasmodium-infected Anophelinae was 00:00-03:00 h. The presence of Plasmodium-infected mosquitoes was higher in landscapes with > 13 malaria cases. CONCLUSIONS: Nyssorhynchus darlingi, Ny. rangeli, Ny. benarrochi B and Ny. konderi B can be involved in malaria transmission in rural settlements. The highest fraction of Plasmodium-infected Anophelinae was caught from midnight to 03:00 h. In some Amazonian localities, the highest exposure to infectious bites occurs when residents are sleeping, but transmission can occur throughout the night. Forest fragmentation favors increases in both malaria and the occurrence of Plasmodium-infected mosquitoes in peridomestic habitat. The use of insecticide-impregnated mosquito nets can decrease human exposure to infectious Anophelinae and malaria transmission.
Subject(s)
Culicidae , Animals , Brazil/epidemiology , Culicidae/parasitology , Culicidae/physiology , Ecosystem , Feeding Behavior , Humans , Insect Bites and Stings , Malaria/epidemiology , Malaria/transmission , Mosquito Vectors/parasitology , Mosquito Vectors/physiology , Plasmodium/isolation & purification , PrevalenceABSTRACT
The relationship between deforestation and malaria is a spatiotemporal process of variation in Plasmodium incidence in human-dominated Amazonian rural environments. The present study aimed to assess the underlying mechanisms of malarial exposure risk at a fine scale in 5-km2 sites across the Brazilian Amazon, using field-collected data with a longitudinal spatiotemporally structured approach. Anopheline mosquitoes were sampled from 80 sites to investigate the Plasmodium infection rate in mosquito communities and to estimate the malaria exposure risk in rural landscapes. The remaining amount of forest cover (accumulated deforestation) and the deforestation timeline were estimated in each site to represent the main parameters of both the frontier malaria hypothesis and an alternate scenario, the deforestation-malaria hypothesis, proposed herein. The maximum frequency of pathogenic sites occurred at the intermediate forest cover level (50% of accumulated deforestation) at two temporal deforestation peaks, e.g., 10 and 35 years after the beginning of the organization of a settlement. The incidence density of infected anophelines in sites where the original forest cover decreased by more than 50% in the first 25 years of settlement development was at least twice as high as the incidence density calculated for the other sites studied (adjusted incidence density ratio = 2.25; 95% CI, 1.38-3.68; p = 0.001). The results of this study support the frontier malaria as a unifying hypothesis for explaining malaria emergence and for designing specific control interventions in the Brazilian Amazon.
Subject(s)
Anopheles/physiology , Conservation of Natural Resources , Malaria/transmission , Mosquito Vectors/physiology , Animals , Anopheles/parasitology , Brazil , Humans , Malaria/epidemiology , Mosquito Vectors/parasitology , Plasmodium falciparum/pathogenicity , Rainforest , Spatio-Temporal AnalysisABSTRACT
BACKGROUND: Brazilian malaria control programmes successfully reduced the incidence and mortality rates from 2005 to 2016. Since 2017, increased malaria has been reported across the Amazon. Few field studies focus on the primary malaria vector in high to moderate endemic areas, Nyssorhynchus darlingi, as the key entomological component of malaria risk, and on the metrics of Plasmodium vivax propagation in Amazonian rural communities. METHODS: Human landing catch collections were carried out in 36 houses of 26 communities in five municipalities in the Brazilian states of Acre, Amazonas and Rondônia states, with API (> 30). In addition, data on the number of locally acquired symptomatic infections were employed in mathematical modelling analyses carried out to determine Ny. darlingi vector competence and vectorial capacity to P. vivax; and to calculate the basic reproduction number for P. vivax. RESULTS: Entomological indices and malaria metrics ranged among localities: prevalence of P. vivax infection in Ny. darlingi, from 0.243% in Mâncio Lima, Acre to 3.96% in Machadinho D'Oeste, Rondônia; daily human-biting rate per person from 23 ± 1.18 in Cruzeiro do Sul, Acre, to 66 ± 2.41 in Lábrea, Amazonas; vector competence from 0.00456 in São Gabriel da Cachoeira, Amazonas to 0.04764 in Mâncio Lima, Acre; vectorial capacity from 0.0836 in Mâncio Lima, to 1.5 in Machadinho D'Oeste. The estimated R0 for P. vivax (PvR0) was 3.3 in Mâncio Lima, 7.0 in Lábrea, 16.8 in Cruzeiro do Sul, 55.5 in São Gabriel da Cachoeira, and 58.7 in Machadinho D'Oeste. Correlation between P. vivax prevalence in Ny. darlingi and vector competence was non-linear whereas association between prevalence of P. vivax in mosquitoes, vectorial capacity and R0 was linear and positive. CONCLUSIONS: In spite of low vector competence of Ny. darlingi to P. vivax, parasite propagation in the human population is enhanced by the high human-biting rate, and relatively high vectorial capacity. The high PvR0 values suggest hyperendemicity in Machadinho D'Oeste and São Gabriel da Cachoeira at levels similar to those found for P. falciparum in sub-Saharan Africa regions. Mass screening for parasite reservoirs, effective anti-malarial drugs and vector control interventions will be necessary to shrinking transmission in Amazonian rural communities, Brazil.
Subject(s)
Anopheles/parasitology , Basic Reproduction Number , Insect Bites and Stings/epidemiology , Malaria, Vivax/epidemiology , Mosquito Vectors/parasitology , Animals , Brazil/epidemiology , Humans , Malaria, Vivax/parasitology , Plasmodium vivax/physiologyABSTRACT
BACKGROUND: Deforestation in the Amazon and the social vulnerability of its settler communities has been associated with increased malaria incidence. The feeding biology of the most important malaria vectors in the region, notably Nyssorhynchus darlingi, compounds efforts to control vectors and reduce transmission of what has become known as "Frontier Malaria". Exploring Anophelinae mosquito diversity is fundamental to understanding the species responsible for transmission and developing appropriate management and intervention strategies for malaria control in the Amazon River basin. METHODS: This study describes Anophelinae mosquito diversity from settler communities affected by Frontier Malaria in the states of Acre, Amazonas and Rondônia by analysing COI gene data using cluster and tree-based species delimitation approaches. RESULTS: In total, 270 specimens from collection sites were sequenced and these were combined with 151 reference (GenBank) sequences in the analysis to assist in species identification. Conservative estimates found that the number of species collected at these sites was between 23 (mPTP partition) and 27 (strict ABGD partition) species, up to 13 of which appeared to be new. Nyssorhynchus triannulatus and Nyssorhynchus braziliensis displayed exceptional levels of intraspecific genetic diversity but there was little to no support for putative species complex status. CONCLUSIONS: This study demonstrates that Anophelinae mosquito diversity continues to be underestimated in poorly sampled areas where frontier malaria is a major public health concern. The findings will help shape future studies of vector incrimination and transmission dynamics in these areas and support efforts to develop more effective vector control and transmission reduction strategies in settler communities in the Amazon River basin.
Subject(s)
Biodiversity , Culicidae/classification , Mosquito Vectors/classification , Animals , Brazil , Cluster Analysis , DNA Barcoding, Taxonomic , Malaria/transmission , Poisson DistributionABSTRACT
The subgenus Melanoconion of the mosquito genus Culex is taxonomically diverse and is widely distributed in the Neotropical Region, with 10 species occurring in the Nearctic Region. Species of this subgenus pose a taxonomical challenge because morphological identification is based largely on anatomical characters of the male genitalia. We addressed the monophyly of the Spissipes and Melanoconion Sections of the subgenus Melanoconion and some of the informal groups in each section. Our sample taxa included 97 specimens representing 43 species, from which we analysed fragments of two single-copy nuclear genes (CAD, HB) and one mitochondrial gene (COI). Phylogenetic relationships within the subgenus are presented based on results of maximum-likelihood and Bayesian analyses using a multi-locus matrix of DNA sequences. We show a molecular phylogeny of Melanoconion in which both sections were recovered as monophyletic groups. The monophyly of the Atratus and Pilosus groups was confirmed. Within each section, other monophyletic groups were recovered highlighting the potential need for future nomenclature rearrangement. The phylogenetic signal contained in nuclear genes, when analysed together, was more informative than each gene analysed separately, corroborating monophyly of Melanoconion relative to Culex (Culex) species included in the analyses, the Melanoconion and Spissipes Sections and some species groups. Our results provide new information for the classification of the subgenus and additional data that can be used to improve species identification when a more representative taxon sampling is available.
ABSTRACT
Culex coronator Dyar and Knab and Culex usquatus Dyar belong to the Coronator Group of the subgenus Culex. Culex coronator and Cx. usquatus are widespread and sympatric throughout their distribution range, which includes Brazil. Morphological identification of these species is based primarily on the characteristics of the male genitalia; females are indistinguishable using the qualitative characteristics employed in identification keys. The primary objective of this study was to distinguish females of Cx. coronator from those of Cx. usquatus employing both wing geometric morphometrics, and DNA sequences (NADH5, COI, Hunchback, and CAD). Additionally, we employed the isolation with migration model (IMa) to evaluate: 1) the migration rates and 2) the divergence time, between Cx. coronator and Cx. usquatus. Specimens were captured in Pariquera-Açu and Cananéia south-eastern São Paulo, Ribeira Valley, Brazil. Canonical variate analysis (CVA) demonstrated two groups in the morphospace. The accuracy of species recognition was moderate (82.6%) for Cx. coronator and low (60.8%) for Cx. usquatus. Bayesian analyses of concatenated gene sequences recovered from specimens of Cx. coronator separated the species into three lineages (herein referred to as Culex coronator A, B, and C), whereas Cx. usquatus specimens clustered into a single lineage. Lineages A and B of Cx. coronator intermixed with specimens of Cx. usquatus, and one specimen of Cx. coronator clustered into the Cx. usquatus lineage. The IMa analysis indicated that the divergence of Cx. coronator and Cx. usquatus is a slow process, with some degree of gene flow between the two species.
Subject(s)
Culex/anatomy & histology , Culex/genetics , Evolution, Molecular , Wings, Animal/anatomy & histology , Animals , Brazil , Female , Insect Proteins/genetics , Male , Phylogeny , Sequence Analysis, DNAABSTRACT
The subgenus Melanoconion is the second largest subgenus within the genus Culex, with 160 described species. Several of the species are proven vectors of arboviruses, including West Nile virus, Venezuelan equine encephalitis virus complex and Eastern equine encephalomyelitis virus. Species of Melanoconion are well distributed from southern North America to most countries of South America and display the highest species diversity in tropical regions. Taxonomical identification within this group has been primarily based on morphological characters, with the male genitalia as the source of the most solid diagnostic features. The difficulty in reaching accurate species determinations when studying specimens of Culex (Melanoconion) has been extensively documented as a real limitation to expand knowledge of these insects. We tested the utility of the mitochondrial gene COI as a complementary tool in the taxonomy of Melanoconion. Using a data set of 120 COI sequences from Culex specimen captured in several localities in Brazil, the utility of COI barcodes for species delimitation is discussed through the evaluation of genetic divergences among specimens and the clustering patterns of species in three topologies obtained with Neighbor Joining, Maximum Likelihood and Bayesian phylogenetic inference. For all specimens included in this study a previous morphological examination was performed, and most of the taxonomical determinations were corroborated using the COI barcode. We generated COI sequences that belong to 48 species of Melanoconion, with a mean intraspecific K2P genetic divergence of 3%; and all interspecific divergence values higher than the intraspecific divergence values. This is the first comprehensive study of subgenus Melanoconion, with evidence of COI as a useful and accessible DNA barcode.
Subject(s)
Culex/genetics , Cyclooxygenase 1/genetics , Insect Proteins/analysis , Insect Vectors/genetics , Mitochondria/genetics , Animals , Bayes Theorem , Brazil , Cluster Analysis , Culex/classification , DNA Barcoding, Taxonomic , Insect Vectors/classification , PhylogenyABSTRACT
BACKGROUND: The Coronator Group currently encompasses six morphologically similar species (Culex camposi Dyar, Culex coronator Dyar and Knab, Culex covagarciai Forattini, Culex usquatus Dyar, Culex usquatissimus Dyar, and Culex ousqua Dyar). Culex coronator has been incriminated as a potential vector of West Nile Virus (WNV), Saint Louis Encephalitis Virus (SLEV), and Venezuelan Equine Encephalitis Virus (VEEV). The complete mitochondrial genome of Cx. coronator, Cx. usquatus, Cx.usquatissimus, and Cx. camposi was sequenced, annotated, and analyzed to provide genetic information about these species. RESULTS: The mitochondrial genomes of Cx. coronator, Cx. usquatus, Cx.usquatissimus, and Cx. camposi varied from 15,573 base pairs in Cx. usquatus to 15,576 in Cx. coronator. They contained 37 genes (13 protein-encoding genes, 2 rRNA genes, and 22 tRNA genes) and the AT-rich control region. Comparative analyses of the 37 genes demonstrated the mitochondrial genomes to be composed of variable and conserved genes. Despite the small size, the ATP8, ATP6 plus NADH5 protein-encoding genes were polymorphic, whereas tRNAs and rRNAs were conserved. The control region contained some poly-T stretch. The Bayesian phylogenetic tree corroborated that both the Coronator Group and the Culex pipens complex are monophyletic taxa. CONCLUSIONS: The mitochondrial genomes of Cx. coronator, Cx. usquatus, Cx. usquatissimus and Cx. camposi share the same gene composition and arrangement features that match to those reported for most Culicidae species. They are composed of the same 37 genes and the AT-rich control region, which contains poly-T stretches that may be involved in the functional role of the mitochondrial genome. Taken together, results of the dN/dS ratios, the sliding window analyses and the Bayesian phylogenetic analyses suggest that ATP6, ATP8 and NADH5 are promising genes to be employed in phylogenetic studies involving species of the Coronator Group, and probably other species groups of the subgenus Culex. Bayesian topology corroborated the morphological hypothesis of the Coronator Group as monophyletic lineage within the subgenus Culex.
Subject(s)
Culex/genetics , Genome, Insect , Genome, Mitochondrial , Animals , Base Composition , Brazil , Codon , Computational Biology , Culex/classification , Genes, Insect , Genes, Mitochondrial , Genomics/methods , High-Throughput Nucleotide Sequencing , Insect Vectors , Molecular Sequence Annotation , Open Reading Frames , PhylogenyABSTRACT
The Anopheles albitarsis group of mosquitoes comprises eight recognized species and one mitochondrial lineage. Our knowledge of malaria vectorial importance and the distribution and evolution of these taxa is incomplete. We constructed ecological niche models (ENMs) for these taxa and used hypothesized phylogenetic relationships and ENMs to investigate environmental and ecological divergence associated with speciation events. Two major clades were identified, one north (Clade 1) and one south (Clade 2) of the Amazon River that likely is or was a barrier to mosquito movement. Clade 1 species occur more often in higher average temperature locations than Clade 2 species, and taxon splits within Clade 1 corresponded with a greater divergence of variables related to precipitation than was the case within Clade 2. Comparison of the ecological profiles of sympatric species and sister species support the idea that phylogenetic proximity is related to ecological similarity. Anopheles albitarsis I, An. janconnae, and An. marajoara ENMs had the highest percentage of their predicted suitable habitat overlapping distribution models of Plasmodium falciparum and P. vivax, and warrant additional studies of the transmission potential of these species. Phylogenetic proximity may be related to malaria vectorial importance within the Albitarsis Group.
Subject(s)
Anopheles/physiology , Animals , Biological Evolution , Ecology , PhylogenyABSTRACT
Specimens of neotropical Anopheles (Nyssorhynchus) were collected and identified morphologically. We amplified three genes for phylogenetic analysis-the single copy nuclear white and CAD genes, and the COI barcode region. Since we had multiple specimens for most species we were able to test how well the single or combined genes were able to corroborate morphologically defined species by placing the species into exclusive groups. We found that single genes, including the COI barcode region, were poor at confirming species, but that the three genes combined were able to do so much better. This has implications for species identification, species delimitation, and species discovery, and we caution that single genes are not enough. Higher level groupings were partially resolved with some well-supported groupings, whereas others were found to be either polyphyletic or paraphyletic. There were examples of known groups, such as the Myzorhynchella Section, which were poorly supported with single genes but were well supported with combined genes. From this we can infer that more sequence data will be needed in order to show more higher-level groupings with good support. We got unambiguously good support (0.94-1.0 Bayesian posterior probability) from all DNA-based analyses for a grouping of An. dunhami with An. nuneztovari and An. goeldii, and because of this and because of morphological similarities we propose that An. dunhami be included in the Nuneztovari Complex. We obtained phylogenetic corroboration for new species which had been recognised by morphological differences; these will need to be formally described and named.
Subject(s)
ATP-Binding Cassette Transporters/genetics , Anopheles/genetics , DNA/genetics , Electron Transport Complex IV/genetics , Insect Proteins/genetics , Phylogeny , Transcription Factors/genetics , ATP-Binding Cassette Transporters/classification , Animals , Anopheles/classification , Bayes Theorem , DNA/classification , Electron Transport Complex IV/classification , Female , Insect Proteins/classification , Male , Phylogeography , South America , Species Specificity , Transcription Factors/classificationABSTRACT
Sequences of the cytochrome c oxidase subunit I (COI) mitochondrial gene from adults of 22 Culex (Culex) species from Argentina and Brazil were employed to assess species identification and to test the usefulness of COI for barcoding using the best close match (BCM) algorithm. A pairwise Kimura two-parameter distance matrix including the mean intra and interspecific distances for 71 COI barcode sequences was constructed. Of the 12 COI lineages recovered in the Neighbour-joining topology, five confirmed recognised morphological species (Cx. acharistus, Cx. chidesteri, Cx. dolosus, Cx. lygrus and Cx. saltanensis) with intraspecific divergences lower than 1.75%. Cx. bilineatus is formally resurrected from the synonymy of Cx. dolosus. Cx. maxi , Cx. surinamensis and the Coronator group species included were clustered into an unresolved lineage. The intraspecific distance of Cx. pipiens (3%) was almost twice the interspecific between it and Cx. quinquefasciatus (1.6%). Regarding the BCM criteria, the COI barcode successfully identified 69% of all species. The rest of the sequences, approximately 10%, 18% and 3%, remained as ambiguously, mis and unidentified, respectively. The COI barcode does not contain enough information to distinguish Culex (Cux.) species.
Subject(s)
Animal Identification Systems/statistics & numerical data , Classification/methods , Culex/anatomy & histology , Culex/genetics , DNA Barcoding, Taxonomic/statistics & numerical data , Electron Transport Complex IV/genetics , Algorithms , Animals , Argentina , Brazil , Cluster Analysis , Culex/classification , Polymerase Chain ReactionABSTRACT
Two new records of Anopheles homunculus in the eastern part of the Atlantic Forest are reported. This species was found for the first time in Barra do Ouro district, Maquiné municipality, Rio Grande do Sul state, located in the southern limit of the Atlantic Forest. The 2nd new record was in the Serra Bonita Reserve, Camacan municipality, southeast Bahia state. These records extend the geographical distribution of An. homunculus, suggesting that the species may be widely distributed in coastal areas of the Atlantic Forest. It is hypothesized that the disjunct distribution of the species may be caused by inadequate sampling, and also difficulties in species identification based only on female external characteristics. Species identification was based on morphological characters of the male, larva, and pupa, and corroborated by DNA sequence analyses, employing data from both 2nd internal transcribed spacer of nuclear ribosomal DNA and of mitochondrial cytochrome c oxidase subunit I.