Vectors
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BACKGROUND: Sand flies are vectors of Leishmania spp., the causative agents of leishmaniasis in vertebrates, including man. The sand fly saliva contains powerful pharmacologically active substances that prevent hemostasis and enhance Leishmania spp. infections. On the other hand, salivary proteins can protect vaccinated mice challenged with parasites. Therefore, sand fly salivary proteins are relevant for the epidemiology of leishmaniasis and can be a potential target for a vaccine against leishmaniasis. Despite this, studies on sand fly salivary glands (SGs) are limited. METHODS: The present study analyzes, in detail, the morphology, anatomy and ultrastructure of the SGs of sand fly vectors of the genera Lutzomyia and Phlebotomus. We used histology, transmission and scanning electron microscopy and lectin labeling associated with confocal laser microscopy. RESULTS: The SGs have conserved and distinct morphological aspects according to the distinct sand fly species. Each SG has a single rounded lobe constituting of c.100-120 secretory cells. The SG secretory cells, according to their ultrastructure and lectin binding, were classified into five different subpopulations, which may differ in secretory pathways. CONCLUSIONS: To the best of our knowledge, these morphological details of sand fly salivary glands are described for the first time. Further studies are necessary to better understand the role of these different cell types and better relate them with the production and secretion of the saliva substances, which has a fundamental role in the interaction of the sand fly vectors with Leishmania.
- Klíčová slova
- Lectin binding, Sand fly vectors, Secretory cell population, Ultrastructure,
- MeSH
- elektronová mikroskopie MeSH
- infekce přenášené vektorem MeSH
- komáří přenašeči anatomie a histologie parazitologie ultrastruktura MeSH
- leishmanióza přenos MeSH
- Phlebotomus anatomie a histologie parazitologie ultrastruktura MeSH
- Psychodidae anatomie a histologie parazitologie ultrastruktura MeSH
- slinné žlázy parazitologie ultrastruktura MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The review is devoted to the gut lectins/hemagglutinins of the following representatives of important disease vectors: ticks, kissing-bugs, mosquitoes, sandflies and tsetse flies. The paper surveys the recent knowledge on these carbohydrate binding factors with respect to their structural and functional properties, and their significance for pathogen/parasite transmission by the blood-sucking arthropods. Recent results suggest that in most vectors the gut lectin activities are blood-meal enhanced, might participate in blood-meal processing and digestion and could serve as antibacterial and antiparasitic agents.
A method for the preparation and regeneration of protoplasts of Streptomyces lincolnensis is described. Mycelium in the early exponential phase appeared to be most suitable for this purpose and yielded up to 25% regenerated intact cells. Transformation of S. lincolnensis protoplasts was achieved using broad-host-range streptomycete plasmid vectors pIJ622, pMP66, pRS410 and pIJ943 constructed from replicons pIJ101, pSLG33 and SCP2. The efficiency of transformation was 3.10(3) transformants per micrograms plasmid DNA when (2-5).10(7) recipient protoplasts were used. Interspecific transformations showed that there is no efficient restriction system in S. lincolnensis that would limit the transfer of genetic information from S. lividans or E. coli.
Arthropod disease vectors not only transmit malaria but many other serious diseases, many of which are, to a greater or lesser degree, neglected [...].
New cloning vectors were prepared with the aid of a large plasmid isolated from Acetobacter pasteurianus and from plasmids pBR322 and pUC4-KAPA. Of the prepared cloning vectors, pACK5 contains a gene coding for kanamycin resistance, pACT7 and pACT71 contain a gene coding for tetracycline resistance and vector pACG3 with a gene coding for both kanamycin and tetracycline resistance. The vectors prepared only contained the beginning of replication from the pAC1 plasmid and possessed the ability to replicate within E. coli and A. pasteurianus. The vectors are highly stable in both strains and during the 5-d cultivation under nonselective conditions are not eliminated.
- MeSH
- Acetobacter genetika MeSH
- DNA bakterií genetika ultrastruktura MeSH
- elektronová mikroskopie MeSH
- Escherichia coli genetika MeSH
- genetické vektory * MeSH
- klonování DNA MeSH
- plazmidy MeSH
- rezistence na kanamycin genetika MeSH
- rezistence na tetracyklin genetika MeSH
- transformace genetická MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- DNA bakterií MeSH
Novel shuttle promoter-probe vectors replicating in Escherichia coli, Corynebacterium glutamicum, and Rhodococcus erythropolis were constructed on the basis of the C. glutamicum plasmid pCG1. The vectors carry reporter genes coding for fluorescent proteins, which allow the measurement of promoter activities in vivo. The promoter-probe vector pPRE11 contains the rsgfp reporter gene, coding for a variant of green fluorescent protein (GFP) with a red-shifted excitation maximum. To ensure efficient expression of the gfp gene in R. erythropolis from the tested promoters, the promoterless gene gfpuv, with 5' end fusion with the initial six codons of the aph gene and upstream insertion of the aph Shine-Dalgarno sequence, was used as a reporter gene in the promoter-probe vector pEPR1. Insertion of the rfp reference gene, coding for a variant of the red fluorescent protein DsRed.T4 and cloned under the strong constitutive C. glutamicum promoter P-45, into the vector pEPR1 resulted in a new-generation promoter-probe vector (pRAG5). All vectors were tested using a set of mutant P-dapA promoters displaying various transcriptional activities. The vector pRAG5 is suitable for normalized measurements of promoter activities during the growth of bacterial batch cultures because estimation of the GFP-to-red fluorescent protein fluorescence ratio in strains carrying the plasmid pRAG5 with the tested promoters upstream of gfpuv avoids the influence of plasmid copy number variations on the promoter activity assay.
- MeSH
- Corynebacterium glutamicum genetika MeSH
- genetické vektory * MeSH
- plazmidy genetika MeSH
- promotorové oblasti (genetika) * MeSH
- Rhodococcus genetika MeSH
- zelené fluorescenční proteiny MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- zelené fluorescenční proteiny MeSH
Site-specific recombinases (SSRs) are critical for achieving precise spatiotemporal control of engineered alleles. These enzymes play a key role in facilitating the deletion or inversion of loci flanked by recombination sites, resulting in the activation or repression of endogenous genes, selection markers or reporter elements. However, multiple recombination in complex alleles can be laborious. To address this, a new and efficient method using AAV vectors has been developed to simplify the conversion of systems based on Cre, FLP, Dre and Vika recombinases. In this study, we present an effective method for ex vivo allele conversion using Cre, FLP (flippase), Dre, and Vika recombinases, employing adeno-associated viruses (AAV) as delivery vectors. AAVs enable efficient allele conversion with minimal toxicity in a reporter mouse line. Moreover, AAVs facilitate sequential allele conversion, essential for fully converting alleles with multiple recombination sites, typically found in conditional knockout mouse models. While simple allele conversions show a 100% efficiency rate, complex multiple conversions consistently achieve an 80% conversion rate. Overall, this strategy markedly reduces the need for animals and significantly speeds up the process of allele conversion, representing a significant improvement in genome engineering techniques.
- Klíčová slova
- 3R, AAV, Flp/FRT, Gene delivery, IVF, Site-specific recombinase,
- MeSH
- alely * MeSH
- blastocysta metabolismus MeSH
- Dependovirus * genetika MeSH
- DNA-nukleotidyltransferasy genetika metabolismus MeSH
- genetické vektory * genetika MeSH
- genová konverze MeSH
- myši MeSH
- rekombinace genetická MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- DNA-nukleotidyltransferasy MeSH
- Site-specific recombinase MeSH Prohlížeč
Viruses from each genus of Bunyaviridae have preferential relationships to the arthropods of only one or two families, i.e. Bunyavirus to mosquitoes (Culicidae), Phlebovirus to sand flies (Psychodidae) and mosquitoes, Uukuvirus and Nairovirus to ticks (Ixodidae and Argasidae). An exception is genus Hantavirus not proven to be transmitted by vectors. Within the Bunyavirus genus 16 serogroups have been recognized on the basis of their antigenic relationship. Based on isolations from the nature each serogroup is preferentially linked with arthropod species (mostly mosquitoes) of one, or two genera. For 8 out of 16 serogroups Culex mosquitoes are the main insect vectors. Two serogroups are linked with Aedes mosquitoes, three with Anopheles mosquitoes. Aedeomyia mosquitoes, Culicoides bitting miges and Hyalomma ticks are vectors of one serogroup each. Evolutionary trends within the genus Bunyavirus and within the family Bunyaviridae can be recognized based on relationships of bunyaviruses to their arthropod vectors.
- MeSH
- antigeny virové imunologie MeSH
- biologická evoluce MeSH
- Bunyaviridae klasifikace genetika imunologie izolace a purifikace fyziologie MeSH
- Ceratopogonidae mikrobiologie MeSH
- členovci - vektory mikrobiologie MeSH
- Culicidae mikrobiologie MeSH
- hmyz - vektory mikrobiologie MeSH
- klíšťata mikrobiologie MeSH
- Psychodidae mikrobiologie MeSH
- RNA virová genetika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- antigeny virové MeSH
- RNA virová MeSH
BACKGROUND: Mosquitoes are arthropods of major importance to animal and human health because they are able to transmit pathogenic agents such as filarioids (Spirurida), vector-borne nematodes, which reside in the tissues of vertebrates. In Europe, recent research has mostly focused on mosquito-borne zoonotic species, while others remain neglected. Mosquitoes are also vectors of avian malaria, which has an almost worldwide distribution, and is caused by several Plasmodium species and lineages, the most common being P. relictum. The Danube Delta region of Romania is one of the most important stopover sites for migratory birds. The local mosquito fauna is diverse and well represented, while filarial infections are known to be endemic in domestic dogs in this area. The aim of the present study was thus to assess the potential vector capacity for various filarial helminths and avian malaria of mosquitoes trapped in the Danube Delta. METHODS: In July 2015, mosquitoes were collected at seven sites located in and around a rural locality in the Danube Delta region of Romania, using CO2-baited traps and hand aspirators. Additionally, a trap was placed next to a microfilaremic dog co-infected with Dirofilaria repens and D. immitis. All randomly trapped mosquitoes were identified to the species level and pooled according to date, sampling site, and taxon. Three hundred individual mosquitoes sampled next to the microfilaremic dog were processed individually and divided into abdomen and thorax/head. Following DNA extraction, all samples were screened for the presence of DNA of filarioid helminths and avian malaria agents by PCR techniques. RESULTS: All 284 pools (a total of 5855 mosquitoes) were negative for filarioid DNA. One pool of Culex modestus mosquitoes was positive for Plasmodium sp. lineage Donana03. In the individually extracted mosquitoes, one abdomen of Aedes vexans was positive for D. repens DNA, one thorax/head of Ae. vexans was positive for DNA of Setaria labiatopapillosa, and two thorax/head of Cx. pipiens f. pipiens were positive for P. relictum lineage pSGS1. CONCLUSION: The present study suggests the vector competence of Cx. modestus and Cx. pipiens for avian Plasmodium including pathogenic species P. relictum and Ae. vexans for mammalian filarioids. Moreover, it indicates the role of Cx. pipiens f. pipiens as a potential natural vector of P. relictum lineage pSGS1 in nature.
- Klíčová slova
- Avian malaria, Danube Delta, Filarioids, Mosquito vectors,
- MeSH
- Aedes klasifikace parazitologie MeSH
- Culex klasifikace parazitologie MeSH
- Culicidae klasifikace parazitologie MeSH
- Dirofilaria immitis genetika izolace a purifikace MeSH
- Dirofilaria repens genetika izolace a purifikace MeSH
- Filarioidea genetika izolace a purifikace MeSH
- filarióza epidemiologie parazitologie MeSH
- hmyz - vektory parazitologie MeSH
- lidé MeSH
- malárie ptačí epidemiologie parazitologie MeSH
- Plasmodium genetika izolace a purifikace MeSH
- psi MeSH
- Setaria (Nematoda) genetika izolace a purifikace MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- psi MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Rumunsko epidemiologie MeSH
In carrying out the national surveillance of vectors and animal reservoirs in Czechoslovakia the theory of the natural focus infections has been taken into account. In order to achieve a successful surveillance, besides studying the distribution of vectors and vertebrate hosts, the greatest emphasis has been put on the compilation of important data concerning their ecology, ethology and phenology. The author refers to some of the practical rsults of the national surveillance programme in Czechoslovakia.
- MeSH
- arachnida jako vektory * MeSH
- ekologie MeSH
- hmyz - vektory * MeSH
- klíšťata MeSH
- lidé MeSH
- zdroje nemoci * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Československo MeSH
