BACKGROUND: Leishmaniasis is a group of neglected vector-borne diseases transmitted by phlebotomine sand flies. Leishmania parasites must overcome various defenses in the sand fly midgut, including the insects's immune response. Insect immunity is regulated by the ecdysone hormone, which binds to its nuclear receptor (EcR) and activates the transcription of genes involved in insect immunity. However, the role of ecdysone in sand fly immunity has never been studied. Phlebotomus perniciosus is a natural vector of Leishmania infantum; here, we manipulated its neuroendocrine system using azadirachtin (Aza), a natural compound known to affect ecdysone synthesis. METHODS: Phlebotomus perniciosus larvae and adult females were fed on food containing either Aza alone or Aza plus ecdysone, and the effects on mortality and ecdysis were evaluated. Genes related to ecdysone signaling and immunity were identified in P. perniciosus, and the expression of antimicrobial peptides (AMPs), EcR, the ecdysone-induced genes Eip74EF and Eip75B, and the transcription factor serpent were analyzed using quantitative polymerase chain reaction (PCR). RESULTS: Aza treatment inhibited molting of first-instar (L1) larvae to L2, with only 10% of larvae molting compared to 95% in the control group. Serpent and Eip74EF, attacin, defensin 1, and defensin 2 genes were downregulated by Aza treatment in larvae. Similarly, Aza-treated adult females also presented suppression of ecdysone signaling-related genes and the AMPs attacin and defensin 2. Notably, all gene repression caused by Aza was reversed by adding ecdysone concomitantly with Aza to the larval or female food, indicating that these genes are effective markers for ecdysone repression. CONCLUSIONS: These results highlight the critical role of ecdysone in regulating the development and immunity of P. perniciosus, which potentially could interfere with Leishmania infection.
- Klíčová slova
- Phlebotomus perniciosus, Antimicrobial peptides, Azadirachtin, Ecdysone,
- MeSH
- antimikrobiální peptidy genetika farmakologie MeSH
- ekdyson * MeSH
- hmyz - vektory účinky léků genetika parazitologie imunologie MeSH
- hmyzí proteiny genetika metabolismus MeSH
- larva * účinky léků imunologie genetika MeSH
- limoniny * farmakologie MeSH
- Phlebotomus * účinky léků genetika parazitologie imunologie MeSH
- shazování tělního pokryvu účinky léků MeSH
- signální transdukce * účinky léků MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antimikrobiální peptidy MeSH
- azadirachtin MeSH Prohlížeč
- ekdyson * MeSH
- hmyzí proteiny MeSH
- limoniny * MeSH
We investigated gene expression patterns in Lutzomyia and Phlebotomus sand fly vectors of leishmaniases. Using quantitative PCR, we assessed the expression stability of potential endogenous control genes commonly used in dipterans. We analyzed Lutzomyia longipalpis and Phlebotomus papatasi samples from L3 and L4 larval stages, adult sand flies of different sexes, diets, dsRNA injection, and Leishmania infection. Six genes were evaluated: actin, α-tubulin, GAPDH, 60 S ribosomal proteins L8 and L32 (RiboL8 and RiboL32), and elongation factor 1-α (EF1-α). EF1-α was among the most stably expressed along with RiboL8 in L. longipalpis larvae and RiboL32 in adults. In P. papatasi, EF1-α and RiboL32 were the top in larvae, while EF1-α and actin were the most stable in adults. RiboL8 and actin were the most stable genes in dissected tissues and infected guts. Additionally, five primer pairs designed for L. longipalpis or P. papatasi were effective in PCR with Lutzomyia migonei, Phlebotomus duboscqi, Phlebotomus perniciosus, and Sergentomyia schwetzi cDNA. Furthermore, L. longipalpis RiboL32 and P. papatasi α-tubulin primers were suitable for qPCR with cDNA from the other four species. Our research provides tools to enhance relative gene expression studies in sand flies, facilitating the selection of endogenous control for qPCR.
- Klíčová slova
- Lutzomyia, Phlebotomus, Endogenous control gene, Gene expression, Gene stability, Reference gene,
- MeSH
- esenciální geny * MeSH
- hmyz - vektory genetika MeSH
- hmyzí geny MeSH
- larva genetika MeSH
- Leishmania genetika MeSH
- Phlebotomus * genetika MeSH
- Psychodidae genetika MeSH
- stanovení celkové genové exprese metody MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The interaction between pathogens and vectors' physiology can impact parasite transmission. Studying this interaction at the molecular level can help in developing control strategies. We study leishmaniases, diseases caused by Leishmania parasites transmitted by sand fly vectors, posing a significant global public health concern. Lipophosphoglycan (LPG), the major surface glycoconjugate of Leishmania, has been described to have several roles throughout the parasite's life cycle, both in the insect and vertebrate hosts. In addition, the sand fly midgut possesses a rich microbiota expressing lipopolysaccharides (LPS). However, the effect of LPG and LPS on the gene expression of sand fly midgut proteins or immunity effectors has not yet been documented. We experimentally fed Lutzomyia longipalpis and Phlebotomus papatasi sand flies with blood containing purified LPG from Leishmania infantum, Leishmania major, or LPS from Escherichia coli. The effect on the expression of genes encoding gut proteins galectin and mucin, digestive enzymes trypsin and chymotrypsin, and antimicrobial peptides (AMPs) attacin and defensins was assessed by quantitative PCR (qPCR). The gene expression of a mucin-like protein in L. longipalpis was increased by L. infantum LPG and E. coli LPS. The gene expression of a galectin was increased in L. longipalpis by L. major LPG, and in P. papatasi by E. coli LPS. Nevertheless, the gene expression of trypsins and chymotrypsins did not significantly change. On the other hand, both L. infantum and L. major LPG significantly enhanced expression of the AMP attacin in both sand fly species and defensin in L. longipalpis. In addition, E. coli LPS increased the expression of attacin and defensin in L. longipalpis. Our study showed that Leishmania LPG and E. coli LPS differentially modulate the expression of sand fly genes involved in gut maintenance and defence. This suggests that the glycoconjugates from microbiota or Leishmania may increase the vector's immune response and the gene expression of a gut coating protein in a permissive vector.
- Klíčová slova
- Bacteria LPS, Digestion, Gut protein, Innate immunity, Leishmania LPG, Lutzomyia, PAMPs, Phlebotomus,
- MeSH
- antimikrobiální peptidy * metabolismus genetika MeSH
- chymotrypsin metabolismus genetika MeSH
- Escherichia coli genetika MeSH
- exprese genu MeSH
- gastrointestinální trakt mikrobiologie parazitologie metabolismus MeSH
- glykosfingolipidy metabolismus MeSH
- hmyz - vektory parazitologie mikrobiologie genetika MeSH
- hmyzí proteiny * genetika metabolismus MeSH
- Leishmania infantum * genetika metabolismus MeSH
- Leishmania major genetika metabolismus MeSH
- lipopolysacharidy * MeSH
- membránové proteiny genetika metabolismus MeSH
- muciny metabolismus genetika MeSH
- PAMP struktury metabolismus MeSH
- Phlebotomus genetika parazitologie metabolismus MeSH
- Psychodidae * parazitologie MeSH
- regulace genové exprese MeSH
- trypsin metabolismus genetika MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antimikrobiální peptidy * MeSH
- attacin antibacterial protein, insect MeSH Prohlížeč
- chymotrypsin MeSH
- glykosfingolipidy MeSH
- hmyzí proteiny * MeSH
- lipophosphonoglycan MeSH Prohlížeč
- lipopolysacharidy * MeSH
- membránové proteiny MeSH
- muciny MeSH
- PAMP struktury MeSH
- trypsin MeSH
Phlebotomine sand flies (Diptera: Phlebotominae) are the principal vectors of Leishmania spp. (Kinetoplastida: Trypanosomatidae). In Central Europe, Phlebotomus mascittii is the predominant species, but largely understudied. To better understand factors driving its current distribution, we infer patterns of genetic diversity by testing for signals of population expansion based on two mitochondrial genes and model current and past climate and habitat suitability for seven post-glacial maximum periods, taking 19 climatic variables into account. Consequently, we elucidate their connections by environmental-geographical network analysis. Most analyzed populations share a main haplotype tracing back to a single glacial maximum refuge area on the Mediterranean coasts of South France, which is supported by network analysis. The rapid range expansion of Ph. mascittii likely started in the early mid-Holocene epoch until today and its spread possibly followed two routes. The first one was through northern France to Germany and then Belgium, and the second across the Ligurian coast through present-day Slovenia to Austria, toward the northern Balkans. Here we present a combined approach to reveal glacial refugia and post-glacial spread of Ph. mascittii and observed discrepancies between the modelled and the current known distribution might reveal yet overlooked populations and potential further spread.
- MeSH
- hmyz - vektory genetika MeSH
- Leishmania * MeSH
- Phlebotomus * genetika MeSH
- Psychodidae * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Evropa MeSH
Triatomine bugs are the blood feeding insect vectors transmitting Chagas disease to humans, a neglected tropical disease that affects over 8 million people, mainly in Latin America. The behavioral responses to host cues and bug signals in Rhodnius prolixus are state dependent, i.e., they vary as a function of post-ecdysis age. At the molecular level, these changes in behavior are probably due to a modulation of peripheral and central processes. In the present study, we report a significant modulation of the expression of a large set of sensory-related genes. Results were generated by means of antennal transcriptomes of 5th instar larvae along the first week (days 0, 2, 4, 6 and 8) after ecdysis sequenced using the Illumina HiSeq platform. Significant age-induced changes in transcript abundance were established for more than 6120 genes (54,7% of 11,186 genes expressed) in the antenna of R. prolixus. This was especially true between the first two days after ecdysis when more than 2500 genes had their expression significantly altered. In contrast, expression profiles were almost identical between day 6 and 8, with only a few genes showing significant modulation of their expression. A total of 86 sensory receptors, odorant carriers and odorant degrading enzymes were significantly modulated across age points and clustered into three distinct expression profiles. The set of sensory genes whose expression increased with age (profile 3) may include candidates underlying the increased responsiveness to host cues shown by R. prolixus during the first days after molting. For the first time, we describe the maturation process undergone at the molecular level by the peripheral sensory system of a hemimetabolous insect.
- Klíčová slova
- Age, Antennae, Rhodnius prolixus, Sensory genes, Transcriptome,
- MeSH
- Chagasova nemoc přenos MeSH
- čich genetika MeSH
- hmyz - vektory genetika metabolismus MeSH
- hmyzí geny * MeSH
- larva genetika metabolismus MeSH
- odoranty MeSH
- receptory pachové genetika metabolismus MeSH
- Rhodnius * genetika metabolismus MeSH
- smyslové orgány * embryologie fyziologie MeSH
- stanovení celkové genové exprese MeSH
- transkriptom MeSH
- tykadla členovců * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- receptory pachové MeSH
BACKGROUND: Phlebotomine sand flies (Diptera: Psychodiae) in the Republic of Moldova have been understudied for decades. Our study provides a first update on their occurrence, species composition and bloodmeal sources after 50 years. METHODS: During 5 seasons (2013-2017), 58 localities from 20 regions were surveyed for presence of sand flies using CDC light traps and manual aspirators. Species identification was done by a combination of morphological and molecular approaches (DNA barcoding, MALDI-TOF MS protein profiling). In engorged females, host blood was identified by three molecular techniques (RFLP, cytb sequencing and MALDI-TOF peptide mass mapping). Population structure of most abundant species was studied by cox1 haplotyping; phylogenetic analyses of ITS2 and cox1 genetic markers were used to resolve relationships of other detected species. RESULTS: In total, 793 sand flies were collected at 30 (51.7%) localities from 12 regions of Moldova. Three species were identified by an integrative morphological and molecular approach: Phlebotomus papatasi, P. perfiliewi and Phlebotomus sp. (Adlerius), the first being the most abundant and widespread, markedly anthropophilic based on bloodmeal analyses, occurring also indoors and showing low population structure with only five haplotypes of cox1 detected. Distinct morphological and molecular characters of Phlebotomus sp. (Adlerius) specimens suggest the presence of a yet undescribed species. CONCLUSIONS: Our study revealed the presence of stable sand fly populations of three species in Moldova that represent a biting nuisance as well as a potential threat of pathogen transmission and shall be further studied.
- Klíčová slova
- Bloodmeal analysis, Haplotype network, MALDI-TOF MS protein profiling, Phlebotomus,
- MeSH
- fylogeneze MeSH
- haplotypy MeSH
- hmyz - vektory klasifikace genetika parazitologie MeSH
- hostitelská specificita MeSH
- leishmanióza přenos MeSH
- lidé MeSH
- Phlebotomus klasifikace genetika fyziologie MeSH
- Psychodidae klasifikace genetika fyziologie MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Moldavsko epidemiologie MeSH
BACKGROUND: Phlebotomine sand flies are the principal vectors of Leishmania spp. (Kinetoplastida: Trypanosomatidae). Information on sand flies in Central Europe is scarce and, to date, in Austria, only Phlebotomus mascittii has been recorded. In 2018 and 2019, entomological surveys were conducted in Austria with the aim to further clarify sand fly distribution and species composition. RESULTS: In 2019, a Ph. simici specimen was trapped in Austria for the first time. Analyses of two commonly used marker genes, cytochrome c oxidase I (coxI) and cytochrome b (cytb), revealed high sequence identity with Ph. simici specimens from North Macedonia and Greece. Phylogenetic analyses showed high intraspecific distances within Ph. simici, thereby dividing this species into three lineages: one each from Europe, Turkey and Israel. Low interspecific distances between Ph. simici, Ph. brevis and an as yet unidentified Adlerius sp. from Turkey and Armenia highlight how challenging molecular identification within the Adlerius complex can be, even when standard marker genes are applied. CONCLUSION: To our knowledge, this study reports the first finding of Ph. simici in Austria, representing the northernmost recording of this species to date. Moreover, it reveals valuable insights into the phylogenetic relationships among species within the subgenus Adlerius. Phlebotomus simici is a suspected vector of L. infantum and therefore of medical and veterinary importance. Potential sand fly expansion in Central Europe due to climatic change and the increasing import of Leishmania-infected dogs from endemic areas support the need for further studies on sand fly distribution in Austria and Central Europe in general.
- Klíčová slova
- Adlerius, Central europe, Leishmania infantum, Phlebotomine sand fly, Refugial area,
- MeSH
- cytochromy b genetika MeSH
- fylogeneze MeSH
- hmyz - vektory klasifikace genetika MeSH
- hmyzí geny MeSH
- infekce přenášené vektorem MeSH
- klasifikace MeSH
- leishmanióza viscerální přenos MeSH
- Phlebotomus * klasifikace genetika MeSH
- Psychodidae * klasifikace genetika MeSH
- respirační komplex IV genetika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Austrálie MeSH
- Názvy látek
- cytochromy b MeSH
- respirační komplex IV MeSH
Many plant viruses are vectored by insects in a persistent circulative manner. The insect gut and salivary gland are important barriers limiting virus spread, but the mechanisms by which viruses are able to cross the gut escape barriers of the insect remain largely unknown. Wheat dwarf virus (WDV), transmitted by Psammotettix alienus in a persistent, circulative, and nonpropagative manner, causes the most economically important virus disease in wheat. In this study, ADP ribosylation factor 1 (ARF1) was found to interact with the coat protein of WDV in a yeast two-hybrid, pull-down assay and to colocalise with virions in the gut and salivary glands of P. alienus. When transcription of ARF1 was suppressed by RNA interference, the WDV titre decreased in the haemolymph and salivary glands, and transmission efficiency decreased, but titre in the gut did not differ from that of the control. These data suggest that ARF1 of P. alienus binds to the WDV virion and helps virus spread from gut to haemolymph. Our study provides direct experimental evidence that WDV can use the existing membrane trafficking mechanism to aid its spread within the insect vector. This first analysis of the molecular interaction between WDV and its vector P. alienus contributes to understanding the mechanisms involved in circulative transmission of the virus by the leafhopper vector.
- Klíčová slova
- ADP ribosylation factor, Psammotettix alienus, transmission mechanism, transport, wheat dwarf virus,
- MeSH
- ADP-ribosylační faktor 1 genetika metabolismus MeSH
- buněčné linie MeSH
- Geminiviridae patogenita MeSH
- Hemiptera genetika metabolismus virologie MeSH
- hmyz - vektory genetika MeSH
- nemoci rostlin virologie MeSH
- RNA interference MeSH
- slinné žlázy metabolismus virologie MeSH
- střeva virologie MeSH
- techniky dvojhybridového systému MeSH
- virion metabolismus MeSH
- virové plášťové proteiny metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- ADP-ribosylační faktor 1 MeSH
- virové plášťové proteiny MeSH
BACKGROUND: Phlebotomine sand flies (Diptera: Psychodidae) are haematophagous insects that transmit the protozoan parasite Leishmania infantum (Kinetoplastida: Trypanosomatidae), the main causative agent of both zoonotic visceral leishmaniasis (VL) and canine leishmaniasis (CanL) in the Mediterranean basin. Eight species of sand flies have been previously recorded in Romania: Phlebotomus papatasi, Phlebotomus alexandri, Phlebotomus sergenti, Phlebotomus perfiliewi, Phlebotomus neglectus, Phlebotomus longiductus, Phlebotomus balcanicus and Sergentomyia minuta. Three of them (P. perfiliewi, P. neglectus and P. balcanicus) were incriminated as vectors of L. infantum. Recent reports of autochthonous CanL in Romania require updates on sand fly distribution and diversity in this country. METHODS: Between 2013-2014 and 2016-2018, CDC light traps and mouth aspirators were used to collect sand flies in 132 locations from Romania, indoors and around various animal species shelters. Species identification of collected specimens was done using morphological keys, genetic tools and MALDI-TOF protein profiling. RESULTS: Sand flies were present in seven localities (5.3%): Eibenthal, Baia Nouă, Gura Văii (south-western Romania, Mehedinţi County); Fundătura, Pâhneşti, Epureni (eastern Romania, Vaslui County); and Schitu (southern Romania, Giurgiu County). Of the total number of collected sand flies (n = 251), 209 (83.27%) were Phlebotomus neglectus, 39 (15.53%) P. perfiliewi, 1 (0.40%) P. papatasi, 1 (0.40%) P. balcanicus and 1 (0.40%) P. sergenti (sensu lato). CONCLUSIONS: We confirmed the presence of five sand fly species previously recorded in Romania. However, their updated distribution differs from historical data. The diversity of sand fly species in Romania and their presence in areas with Mediterranean climatic influences constitutes a threat for the reemergence of vector-borne diseases. In the context of CanL and VL reemergence in Romania, but also due to imported cases of the diseases in both humans and dogs, updates on vector distribution are imperative.
- Klíčová slova
- Canine leishmaniasis, Distribution, Diversity, Romania, Sand flies,
- MeSH
- genetická variace * MeSH
- hmyz - vektory genetika fyziologie MeSH
- Phlebotomus genetika fyziologie MeSH
- rozšíření zvířat * MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Rumunsko MeSH
A large-scale entomological survey was carried out in summer 2016 in the Czech Republic and Slovakia. It revealed, for the first time, the presence of the phlebotomine sand fly Phlebotomus (Transphlebotomus) mascittii Grassi, 1908 (Diptera: Phlebotominae) in south-western Slovakia. Species identification of a captured female was confirmed by both morphological and sequencing (COI) analyses.
Une enquête entomologique à grande échelle a été réalisée durant l'été 2016 en République Tchèque et en Slovaquie. Elle a révélé, pour la première fois, la présence de Phlebotomus (Transphlebotomus) mascittii Grassi, 1908 (Diptera : Phlebotominae) dans le sud-ouest de la Slovaquie. Une femelle a été capturée et son identification repose sur des caractères morphologiques et moléculaires (COI).
- MeSH
- DNA chemie MeSH
- hmyz - vektory genetika fyziologie MeSH
- Phlebotomus genetika fyziologie MeSH
- polymerázová řetězová reakce MeSH
- respirační komplex IV genetika MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Slovenská republika MeSH
- Názvy látek
- DNA MeSH
- respirační komplex IV MeSH