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Molecular Biology and Evolution Aug 2023Though the phylogenetic signal of loci on sex chromosomes can differ from those on autosomes, chromosomal-level genome assemblies for nonvertebrates are still relatively...
Though the phylogenetic signal of loci on sex chromosomes can differ from those on autosomes, chromosomal-level genome assemblies for nonvertebrates are still relatively scarce and conservation of chromosomal gene content across deep phylogenetic scales has therefore remained largely unexplored. We here assemble a uniquely large and diverse set of samples (17 anchored hybrid enrichment, 24 RNA-seq, and 70 whole-genome sequencing samples of variable depth) for the medically important assassin bugs (Reduvioidea). We assess the performance of genes based on multiple features (e.g., nucleotide vs. amino acid, nuclear vs. mitochondrial, and autosomal vs. X chromosomal) and employ different methods (concatenation and coalescence analyses) to reconstruct the unresolved phylogeny of this diverse (∼7,000 spp.) and old (>180 Ma) group. Our results show that genes on the X chromosome are more likely to have discordant phylogenies than those on autosomes. We find that the X chromosome conflict is driven by high gene substitution rates that impact the accuracy of phylogenetic inference. However, gene tree clustering showed strong conflict even after discounting variable third codon positions. Alternative topologies were not particularly enriched for sex chromosome loci, but spread across the genome. We conclude that binning genes to autosomal or sex chromosomes may result in a more accurate picture of the complex evolutionary history of a clade.
Topics: Animals; Phylogeny; Reduviidae; Biological Evolution; Genome; X Chromosome
PubMed: 37494292
DOI: 10.1093/molbev/msad168 -
PLoS Neglected Tropical Diseases Jul 2021Updating the distribution and natural infection status of triatomine bugs is critical for planning, prioritizing, and implementing strategies to control Chagas disease...
Distribution and natural infection status of synantrophic triatomines (Hemiptera: Reduviidae), vectors of Trypanosoma cruzi, reveals new epidemiological scenarios for chagas disease in the Highlands of Colombia.
INTRODUCTION
Updating the distribution and natural infection status of triatomine bugs is critical for planning, prioritizing, and implementing strategies to control Chagas disease (CD), especially after vector reduction programs. After carrying out a control program, the Department of Boyaca contains the highest number of Colombian municipalities certified by PAHO to be free of intradomiciliary transmission of Trypanosoma cruzi by Rhodnius prolixus. The present work describes the spatial distribution, natural infection (NI), and molecular characterization of T. cruzi in synanthropic triatomines from the Department of Boyaca in 2017 and 2018.
MATERIALS AND METHODS
An entomological survey was conducted in 52 municipalities in Boyaca known to have had previous infestations of triatomine bugs. Insects were collected through active searches carried out by technical personnel from the Secretary of Health and community members using Triatomine Collection Stations (PITs-acronym in Spanish). For evaluation of natural infection, triatomines were identified morphologically and grouped in pools of one to five individuals of the same species collected in the same household. DNA derived from the feces of each pool of insects was analyzed by PCR for the presence of T. cruzi using primers flanking the satellite DNA of the parasite. SL-IR primers were used to differentiate TCI from the other DTUs and to identify different genotypes. The distribution of the collected triatomines was analyzed to determine any vector hotspots using spatial recreation.
RESULTS
A total of 670 triatomine bugs was collected, belonging to five species: Triatoma dimidiata (73.2%), Triatoma venosa (16.7%), Panstrongylus geniculatus (5.7%), Rhodnius prolixus (4.4%), and Panstrongylus rufotuberculatus (0.4%), from 29 of the 52 municipalities. In total, 71.6% of the bugs were collected within houses (intradomiciliary) and the rest around the houses (peridomiciliary). Triatoma dimidiata was the most widely distributed species and had the highest natural infection index (37.8%), followed by T. venosa and P. geniculatus. TcI was the only DTU found, with the TcI Dom genotype identified in 80% of positive samples and TcI sylvatic in the other insects. Spatial analysis showed clusters of T. dimidiata and T. venosa in the northeast and southwest regions of Boyaca.
CONCLUSIONS
After some municipalities were certified free of natural transmission within houses (intradomiciliary transmission) of T. cruzi by R. prolixus, T. dimidiata has become the most prevalent vector present, and represents a significant risk of resurgent CD transmission. However, T. venosa, P. geniculatus, and P. rufotuberculatus also contribute to the increased risk of transmission. The presence of residual R. prolixus may undo the successes achieved through vector elimination programs. The molecular and spatial analysis used here allows us to identify areas with an ongoing threat of parasite transmission and improve entomological surveillance strategies.
Topics: Animal Distribution; Animals; Chagas Disease; Colombia; Genotype; Humans; Insect Vectors; Reduviidae; Trypanosoma cruzi
PubMed: 34280203
DOI: 10.1371/journal.pntd.0009574 -
Journal of Vector Ecology : Journal of... Jun 2023is an exclusive and widely distributed species in Mexico and one of the three main vectors that transmit Chagas disease in the country. The state of Hidalgo is an...
is an exclusive and widely distributed species in Mexico and one of the three main vectors that transmit Chagas disease in the country. The state of Hidalgo is an endemic area for Chagas disease where the presence of several species of triatomines has been reported. The objective of our work was to describe the morphology, colonization process, and reproductive behavior of in Guadalupe, Tecozautla, two years after the first collection of a specimen in this region. A total of 28 specimens was collected at both domicile and peridomicile, showing a 17.8% infection rate. The main collection site was a woodshed, and despite the collection of adults in the dwelling, we did not find eggs, exuviae, or nymphs. One female monitored from collection day until death laid 566 eggs, with a hatching rate of 95%, showing an increase of oviposition when cohabited with a male. The results showed the capacity that has to infest areas (mainly human dwellings) when it settles down, which would imply a risk for the population that lives in the locality.
Topics: Male; Female; Humans; Animals; Triatoma; Mexico; Insect Vectors; Triatominae; Chagas Disease; Trypanosoma cruzi
PubMed: 37255353
DOI: 10.52707/1081-1710-48.1.1 -
Frontiers in Cellular and Infection... 2020Triatomines are hematophagous insects that transmit , the etiological agent of Chagas disease. This neglected tropical disease represents a global health issue as it is...
Triatomines are hematophagous insects that transmit , the etiological agent of Chagas disease. This neglected tropical disease represents a global health issue as it is spreading worldwide. The saliva of Triatominae contains miscellaneous proteins crucial for blood feeding acquisition, counteracting host's hemostasis while performing vasodilatory, anti-platelet and anti-coagulant activities, besides modulating inflammation and immune responses. Since a set of biological processes are mediated by protein complexes, here, the sialocomplexomes (salivary protein complexes) of five species of Triatominae were studied to explore the protein-protein interaction networks. Salivary multiprotein complexes from , and were investigated by Blue-Native- polyacrylamide gel electrophoresis coupled with liquid chromatography tandem mass spectrometry. More than 70 protein groups, uncovering the landscape of the Triatominae salivary interactome, were revealed. Triabin, actin, thioredoxin peroxidase and an uncharacterized protein were identified in sialocomplexes of the five species, while hexamerin, heat shock protein and histone were identified in sialocomplexes of four species. Salivary proteins related to triatomine immunity as well as those required during blood feeding process such as apyrases, antigen 5, procalins, and nitrophorins compose different complexes. Furthermore, unique proteins for each triatomine species were revealed. This study represents the first Triatominae sialocomplexome reference to date and shows that the approach used is a reliable tool for the analysis of Triatominae salivary proteins assembled into complexes.
Topics: Animals; Insect Vectors; Proteomics; Saliva; Triatoma; Triatominae; Trypanosoma cruzi
PubMed: 32984079
DOI: 10.3389/fcimb.2020.00459 -
Archives of Insect Biochemistry and... Jul 2023Saliva of hematophagous insects contains many different compounds, mainly acting as anticoagulants. Investigating the bacteriolytic compounds of the saliva of the...
Saliva of hematophagous insects contains many different compounds, mainly acting as anticoagulants. Investigating the bacteriolytic compounds of the saliva of the bloodsucking Triatoma infestans photometrically between pH 3 and pH 10 using unfed fifth instars and nymphs up to 15 days after feeding, we found bacteriolytic activity against lyophilized Micrococcus luteus was stronger at pH 4 and pH 6. After feeding, the activity level at pH 4 was unchanged, but at pH 6 more than doubled between 3 and 7 days after feeding. In zymographs of the saliva and after incubation at pH 4, bacteriolytic activity against Micrococcus luteus was present at eight lysis zones between 14.1 and 38.5 kDa, showing the strongest activity at 24.5 kDa. After incubation at pH 6, lysis zones only appeared at 15.3, 17, and 31.4 kDa. Comparing zymographs of the saliva of unfed and fed nymphs, bacteriolytic activity at 17 kDa increased after feeding. In total nine lysis bands appeared, also at >30 kDa, so far unreported in the saliva of triatomines. Reverse transcription polymerase chain reaction using oligonucleotides based on the previously described lysozyme gene of T. infestans, TiLys1, verified expression of genes encoding TiLys1 and TiLys2 in the salivary glands, but also of an undescribed third lysozyme, TiLys3, of which the cloned cDNA shares characteristics with other c-type lysozymes of insects. While TiLys1 was expressed in the tissue of all three salivary glands, transcripts of TiLys2 and of TiLys3 seem to be present only in the gland G1 and G3, respectively.
Topics: Animals; Triatoma; Saliva; Muramidase; Feeding Behavior; Salivary Glands
PubMed: 36973856
DOI: 10.1002/arch.22013 -
Journal of Medical Entomology Nov 2022Triatoma dimidiata (Latreille 1811) is considered the second most important vector of the Trypanosa cruzi etiological agent of Chagas disease in Colombia. It has a life...
Characterization of Feeding Behavior and its Relationship With the Longevity of Wild and Peridomestic Triatoma dimidiata, Latreille 1811 (Hemiptera, Reduviidae) Under Laboratory Conditions.
Triatoma dimidiata (Latreille 1811) is considered the second most important vector of the Trypanosa cruzi etiological agent of Chagas disease in Colombia. It has a life cycle that involves a domiciled, peridomiciled, and wild distribution. The study of feeding behavior and its influence on the survival of sylvatic and peridomestic populations can help identify a possible differential risk in the transmission of Chagas disease to humans, mainly in northwestern and east-central Colombia. We characterize the main parameters of feeding behavior and their influence on the longevity and survival of two rat-fed populations of T. dimidiata from Colombia, one in the north-west (from palms in a tropical dry forest area) and the other in the center-east (peridomiciliated), under controlled environmental conditions. The palm population took considerably longer than the peridomestic population to complete its life cycle under experimental laboratory conditions, being both populations univoltine since they have only one life cycle per year. Statistically significant differences were evidenced using Box-Cox model between the survival rates of T. dimidiata populations when the parameters related to blood intake and behavior were incorporated, in contrast to the survival models in which the origin only was considered as a factor. Our results could be used to generate recommendations to guide prevention strategies in communities near sylvatic and peridomiciliated populations of T. dimidiata.
Topics: Animals; Humans; Rats; Chagas Disease; Environment; Feeding Behavior; Longevity; Triatoma; Trypanosoma cruzi
PubMed: 35980342
DOI: 10.1093/jme/tjac122 -
Journal of Medical Entomology Nov 2017The insect integument, formed by the cuticle and the underlying epidermis, is essential for insect fitness, regulation of lipid biosynthesis and storage, insect growth...
The insect integument, formed by the cuticle and the underlying epidermis, is essential for insect fitness, regulation of lipid biosynthesis and storage, insect growth and feeding, together with development progress. Its participation in insecticide resistance has also been outlined. Triatoma infestans Klug (Hemiptera: Reduviidae) is one of the major vectors of Chagas disease in South America; however, genomic data are scarce. In this study, we performed a transcriptome analysis of the nymph integument in order to identify which genes are expressed and their putative role. Using the 454 GS-FLX sequencing platform, we obtained approximately 144,620 reads from the integument tissue. These reads were assembled into 6,495 isotigs and 8,504 singletons. Based on BLAST similarity searches, about 8,000 transcripts were annotated with known genes, conserved domains, and/or Gene Ontology terms.The most abundant transcripts corresponded to transcription factors and nucleic acid metabolism, membrane receptors, cell signaling, and proteins related to cytoskeleton, transport, and cell energy processes, among others. More than 10% of the transcripts-encoded proteins putatively involved in the metabolism of fatty acids and related components (fatty acid synthases, elongases, desaturases, fatty alcohol reductases), structural integument proteins, and the insecticide detoxification system (among them, cytochrome P450s, esterases, and glutathione transferases). Real-time qPCR assays were used to investigate their putative participation in the resistance mechanism. This preliminary study is the first transcriptome analysis of a triatomine integument, and together with prior biochemical information, will help further understandthe role of the integument in a wide array of mechanisms.
Topics: Animals; Gene Expression Profiling; Insecticide Resistance; Lipid Metabolism; Triatoma
PubMed: 29029205
DOI: 10.1093/jme/tjx151 -
Zootaxa Jun 2022The Apiomerus maya species group of the genus Apiomerus Hahn, 1831 (Hemiptera: Heteroptera: Reduviidae: Harpactorinae: Apiomerini), the bee assassins, is revised. Four...
The Apiomerus maya species group of the genus Apiomerus Hahn, 1831 (Hemiptera: Heteroptera: Reduviidae: Harpactorinae: Apiomerini), the bee assassins, is revised. Four species that are native to parts of Mexico and Central America are recognized and redescribed: Apiomerus maya Dispons, 1971, A. pipil Dispons, 1971, A. venosus Stl, 1872, and A. immundus Bergroth, 1898. Intraspecific polychromatism and male genital morphology are documented for the group. The taxonomy of two previously recognized species is updated: A. tristis Champion, 1899 syn. nov. is here synonymized with A. venosus and A. guatemalensis Dispons, 1971 syn. nov. with A. pipil.
Topics: Animal Distribution; Animals; Bees; Male; Reduviidae
PubMed: 36095603
DOI: 10.11646/zootaxa.5154.5.3 -
Acta Tropica Dec 2020Chagas disease, whose etiological agent is the protozoan Trypanosoma cruzi, affects millions of people worldwide and it is mainly transmitted by infected triatomine...
Chagas disease, whose etiological agent is the protozoan Trypanosoma cruzi, affects millions of people worldwide and it is mainly transmitted by infected triatomine feces. Triatoma is the most diverse genus and one of the most important from an epidemiological point of view. Species of this genus are grouped into eight complexes and nine subcomplexes. Triatoma sordida subcomplex consists of T. garciabesi, T. guasayana, T. patagonica, and, T. sordida. Given the recent discussions on their phylogenetic status, this study aims to evaluate morphometric and genetics characters that group and distinguish T. garciabesi, T. guasayana, T. patagonica, and T. sordida, as well as to infer the phylogenetic relationships within the group and evaluate the proximity with T. rubrovaria subcomplex. The results corroborate the phylogenetic relationship of T. guasayana and T. patagonica with the T. rubrovaria subcomplex. Molecular data confirm the proximity of T. jurbergi, T. matogrossensis, T. vandae as T. garciabesi, and T. sordida. Together, genetic variability was shown between T. sordida populations.
Topics: Animals; Chagas Disease; Insect Vectors; Phenotype; Phylogeny; Triatoma
PubMed: 32860747
DOI: 10.1016/j.actatropica.2020.105679 -
International Journal of Biological... Aug 2019The reduviid subfamily Triatominae, also called kissing bugs, are vectors of Chagas disease, which is one of the most seriously neglected tropical parasitic diseases....
The reduviid subfamily Triatominae, also called kissing bugs, are vectors of Chagas disease, which is one of the most seriously neglected tropical parasitic diseases. Only three complete mitochondrial genomes of kissing bugs from the genus Triatoma have been sequenced to date. To better understand the diversity of mitochondrial genomes and the evolution of kissing bugs, mitochondrial genomes of three kissing bugs, Triatoma migrans, Panstrongylus rufotuberculatus, and Rhodnius pictipes, were sequenced using next-generation sequencing and a comparative mitochondrial genomic analysis of three genera and two tribes in Triatominae was conducted. Kissing bug mitochondrial genomes shared a similar pattern of nucleotide composition, gene order, and structure of control region. The comparison among orthologous protein-coding genes indicated that different genes had different rates of molecular evolution and six genes (ND1, ND2, ND4L, ND5, ND6, and ATP8) had higher evolutionary rates than other protein-coding genes. Phylogenetic analyses inferred from mitochondrial genome sequences supported a sister relationship between Triatominae and Stenopodainae, and the genus Triatoma was paraphyletic. The present study revealed the high conservation of the mitochondrial genome organization of kissing bugs and highlighted the utility of mitochondrial genomes in the phylogenetic study of Triatominae.
Topics: Animals; Computational Biology; Evolution, Molecular; Gene Order; Genome, Insect; Genome, Mitochondrial; Genomics; High-Throughput Nucleotide Sequencing; Open Reading Frames; Phylogeny; Triatominae; Untranslated Regions
PubMed: 31071392
DOI: 10.1016/j.ijbiomac.2019.05.020