Metaphase karyotypes of Anopheles (Nyssorhynchus) darlingi Root and A. (N.) nuneztovari Gabaldon (Diptera; Culicidae)

Metaphase karyotypes of Anopheles (Nyssorhynchus) darlingi and Anopheles (N.) nuneztovari from Manaus and Highway BR-174 (Manaus-Boa Vista), State of Amazonas, and Macapa, State of Amapa, Brazil, showed 2n = 6. They consisted of a pair of metacentric (chromosome II) and a pair of submetacentric (chromosome III) autosomes as well as sex chromosomes X and Y. In the sex chromosomes, the X was acrocentric in A. darlingi and submetacentric in A. nuneztovari. The Y chromosome was pointed in both species. The chromosomes of A. nuneztovari were larger than those of A. darlingi except for the Y chromosome. A. nuneztovari showed size polymorphism in the X chromosome. Somatic pairing and a strong constriction around the centromeric region in chromosomes II and III were exhibited in both species. The secondary constriction was only detected in chromosome II of A. darlingi from the Manaus population and chromosome III from the Macapa population

Differential expression of genes related to the immune response of anopheles (Nyssorhynchus) darlingi in the brazilian amazon basin

Anopheles (Nyssorhynchus) darlingi is the primary vector of human malaria in South America. Immune responses in mosquito vectors of malaria are mainly regulated by genes of the Toll and IMD pathways through the transcription factors NF-kappa-β, Rel1 and Rel2, which are controlled by the negative regulatory genes Cactus and Caspar. We measured the expression levels of Rel1, Rel2, Caspar and Cactus genes, which are related to the immune system, in adult females of A. darlingi after blood feeding compared to adult females without blood feeding (controls) due to their possible effects on the ability of becoming infected with species of Plasmodium and spreading malaria. Quantitative expression was determined by real-time PCR, using the reference genes GAPDH and β-actin. The expression levels of Rel1, Rel2, Caspar and Cactus varied significantly at 4, 8, 14 and 24 h in mosquitoes that had fed on blood compared to control insects (0 h), with significantly greater expression at 24 h after blood feeding. Relative expression levels among these genes varied at the different post blood feeding times. This information adds to our understanding of the insect immune response system and related questions involved in understanding the biology and control of this mosquito. © FUNPEC-RP

Effect of isodillapiole on the expression of the insecticide resistance genes GSTE7 and CYP6N12 in Aedes aegypti from central Amazonia

The yellow fever mosquito Aedes (Stegomyia) aegypti is the main vector of dengue arbovirus and other arboviruses. Dengue prevention measures for the control of A. aegypti involve mainly the use of synthetic insecticides. The constant use of insecticides has caused resistance in this mosquito. Alternative studies on plant extracts and their products have been conducted with the aim of controlling the spread of the mosquito. Dillapiole is a compound found in essential oils of the plant Piper aduncum (Piperaceae) which has been effective as a biopesticide against A. aegypti. Isodillapiole is a semisynthetic substance obtained by the isomerization of dillapiole. In the present study, isodillapiole was evaluated for its potential to induce differential expression of insecticide resistance genes (GSTE7 and CYP6N12) in 3rd instar larvae of A. aegypti. These larvae were exposed to this compound at two concentrations (20 and 40 μg/mL) for 4 h during four generations (G1, G2, G3, and G4). Quantitative RT-PCR was used to assess the expression of GSTE7 and CYP6N12 genes. GSTE7 and CYP6N12 relative expression levels were higher at 20 than at 40 μg/mL and varied among generations. The decrease in GSTE7 and CYP6N12 expression levels at the highest isodillapiole concentration suggests that larvae may have suffered from metabolic stress, revealing a potential alternative product in the control of A. aegypti. © FUNPEC-RP

Isolation and characterization of polymorphic DNA microsatellite loci for Anopheles triannulatus sensu lato (Diptera: Culicidae) and cross-amplification in congeneric species

Anopheles (Nyssorhynchus) triannulatus is a complex of 3 species. Thirteen polymorphic microsatellite loci were isolated and characterized in 20 to 25 individuals from Manaus (AM, Brazil). The number of alleles per locus varied from 3 to 10 (mean = 6.0). The observed heterozygosity ranged from 0.250 to 0.875 (mean = 0.680) and expected heterozygosity ranged from 0.376 to 0.844 (mean = 0.698). Two loci exhibited null alleles and all loci were in Hardy-Weinberg equilibrium. No linkage disequilibrium between loci was observed. These loci were used in 4 congeneric species and provide a useful tool for studying population genetics and other aspects of the biology of this and other Anopheles species. ©FUNPEC-RP

Physical Mapping of the \u3ci\u3eAnopheles\u3c/i\u3e (\u3ci\u3eNyssorhynchus\u3c/i\u3e) \u3ci\u3edarlingi\u3c/i\u3e Genomic Scaffolds

The genome assembly of Anopheles darlingi consists of 2221 scaffolds (N50 = 115,072 bp) and has a size spanning 136.94 Mbp. This assembly represents one of the smallest genomes among Anopheles species. Anopheles darlingi genomic DNA fragments of ~37 Kb were cloned, end-sequenced, and used as probes for fluorescence in situ hybridization (FISH) with salivary gland polytene chromosomes. In total, we mapped nine DNA probes to scaffolds and autosomal arms. Comparative analysis of the An. darlingi scaffolds with homologous sequences of the Anopheles albimanus and Anopheles gambiae genomes identified chromosomal rearrangements among these species. Our results confirmed that physical mapping is a useful tool for anchoring genome assemblies to mosquito chromosomes

Differential expression of trypsin-3 and phosrestin ii genes in the main malaria vector, Anopheles darlingi, from the Brazilian Amazon Region

Anopheles darlingi is the most anthropophilic mosquito related to Plasmodium infection of malaria, causing significant morbidity and mortality in South America. Pyrethroid chemical has been used to control mosquitos. We analyzed the expression of trypsin-3 and phosrestin II genes implicated to feeding and resistance to insecticides, immune response and sensory antenna mechanisms, respectively, of larvae and adult of A. darlingi, through quantitative reverse transcription polymerase chain reaction (qRT-PCR). We aimed to validate the similarity in nucleotide sequences of A. darlingi RNA sequencing libraries by in silico, and qRT- PCR, owing to their possible effects on the ability to spread disease. The expression of trypsin-3 and phosrestin II was higher in the first and second instar larvae as compared with that in adults. These differentially expressed trypsin-3 and phosrestin II genes do not provide us evidence that both genes participate in pyrethroid resistance. The signaling pathway involving both genes requires further study. Preliminary phylogenetic relationships and the accumulation of mutations analysis in both genes were also compared with trypsin and phosrestin sequences of 15 and 17 other anopheline species, respectively, to obtain a mutational rate of 0.02 on phylogenetic trees. Trypsin gene of A. darlingi and A. albimanus clustered into the same group and was distinct from the species of A. gambiae complex and other anopheline. For phosrestin II, A. darlingi was separated from the remaining species from Africa, Asia, and Europe. Although the groups showed low to moderate support, it is possible to infer that both genes may belong to two evolutionary groups: one presents in the anopheline species of New World and other in the anopheline species of Old World, and be useful for future studies. © 2017 The Authors

Cytogenetic study of Anopheles albitarsis (Diptera: Culicidae) by C-banding and in situ hybridization

The C-banding pattern and the size and location of the nucleolar organizer regions (NORs) are described for the first time in Brazilian populations of Anopheles (Nyssorhynchus) albitarsis sensu lato. C-banding revealed variation in the size of the centromeric heterochromatic blocks in autosomal chromosomes and in the acrocentric (X) and puntiform (Y) sex chromosomes. Fluorescence in situ hybridization showed that the NORs were located in the pericentromeric region of the sex (XX/XY) chromosomes and that this coincided with the number and location of centromeric constitutive heterochromatin blocks previously revealed by C-banding. The NORs varied in size among the homologues of the three populations. These findings of the populations studied support the hypothesis that the stability of NORs in the A. albitarsis complex is characterized by the presence of clustered and conserved sites in a unique pair of chromosomes

Isolation and characterization of 25 microsatellite DNA loci for Anopheles albitarsis sensu lato and inter-specific amplification in 5 congeneric species.

The Anopheles albitasis complex includes 6 species, and 3 are considered as malaria vectors in Brazil. Twenty-five polymorphic microsatellite DNA loci were isolated and characterized in 24-36 individuals from the neighborhood of Puraquequara, Manaus, Amazonas State, Brazil. The number of estimated alleles ranged from 2 to 10, the observed heterozygosity ranged from 0.182 to 0.897, and the expected heterozygosity ranged from 0.260 to 0.854. Eleven loci showed significant deviation from Hardy-Weinberg equilibrium. Eleven loci were cross-amplified successfully in 5 Anopheles species. These microsatellite loci will be useful in studies investigating population structure and evolutionary genetics in A. albitarsis sensu lato and other A. albitarsis complex species

Anopheles darlingi polytene chromosomes: Revised maps including newly described inversions and evidence for population structure in Manaus

Salivary gland polytene chromosomes of 4th instar Anopheles darlingi Root were examined from multiple locations in the Brazilian Amazon. Minor modifications were made to existing polytene photomaps. These included changes to the breakpoint positions of several previously described paracentric inversions and descriptions of four new paracentric inversions, two on the right arm of chromosome 3 and two on the left arm of chromosome 3 that were found in multiple locations. A total of 18 inversions on the X (n = 1) chromosome, chromosome 2 (n = 7) and 3 (n = 11) were scored for 83 individuals from Manaus, Macapá and Porto Velho municipalities. The frequency of 2Ra inversion karyotypes in Manaus shows significant deficiency of heterozygotes (p < 0.0009). No significant linkage disequilibrium was found between inversions on chromosome 2 and 3. We hypothesize that at least two sympatric subpopulations exist within the An. darlingi population at Manaus based on inversion frequencies. © Instituto Oswaldo Cruz - Fundação Oswaldo Cruz - Ministério da Saúde 2016