33 research outputs found
Novel parvovirus from the worm lizard Trogonophis wiegmanni — First virus ever detected in amphisbaenian hosts
To explore the diversity of some DNA viruses in reptiles, a continuous screening is going on, in our laboratory, by PCR using different consensus primers designed for the detection of the most conserved genome regions of adeno-, herpes- and parvoviruses. The test material consists essentially of dead specimens collected randomly from private pet owners, local pet shops, or at occasional exotic pet fairs. Here we report the partial sequence of a putative novel parvovirus obtained from a dead checkerboard worm lizard (Trogonophis wiegmanni) that had been wild-caught in its native habitat. An in-house-developed PCR with consensus primers targeting the gene of the parvoviral capsid protein was used. Other PCRs, intended to detect certain large DNA viruses, remained negative. The sequence of the PCR product indicated the presence of a hitherto unknown parvovirus in the internal organs of the checkerboard worm lizard. In phylogeny reconstruction, the novel sequence clustered with the members of the Dependovirus genus of the Parvoririnae subfamily, closest to the branch of snake adeno-associated virus. Since we could not demonstrate the presence of a potential helper virus, the putative amphisbaenian parvovirus supposedly can replicate autonomously. This is the first virus infection ever detected in any members of the suborder Amphisbaenia, and only the third parvoviral sequence obtained from any reptilian host
First detection of circovirus-like sequences in amphibians and novel putative circoviruses in fishes
The negative samples of a collection, established originally for seeking new adeno- and herpesviruses in lower vertebrates, were screened for the pres-ence of circoviruses by a consensus nested PCR targeting the gene coding for the replication-associated protein. Six fish samples representing five species, namely asp (Aspius aspius), roach (Rutilus rutilus), common bream (Abramis brama), round goby (Neogobius melanostomus) and monkey goby (Neogobius fluviatilis), as well as three frog samples were found positive for circoviral DNA. Sequence analysis of the amplicons indicated the presence of three novel putative circo-like viruses and a circovirus in Hungarian fishes and one novel circovirus in a common toad (Bufo bufo), and another one in a dead and an alive specimen of green tree frog (Litoria caerulea), respectively. In phylogeny reconstruction, the putative bream circovirus clustered together with circoviruses discovered in other cyprinid fishes recently. Three other piscine circoviral sequences appeared closest to sequences derived from different environmental samples. Surprisingly, the nucleotide sequence derived from two fish samples (a bream and a monkey goby) proved to be from porcine circovirus 2 (PCV2), almost identical to a sequence detected in Sweden previously. This is the first report on the detection of PCV2 in fish and circoviral DNA in amphibian hosts
Endogenous amdoparvovirus-related elements reveal insights into the biology and evolution of vertebrate parvoviruses
Amdoparvoviruses (family Parvoviridae: genus Amdoparvovirus) infect carnivores, and are a major cause of morbidity and mortality in farmed animals. In this study, we systematically screened animal genomes to identify endogenous parvoviral elements (EPVs) disclosing a high degree of similarity to amdoparvoviruses, and investigated their genomic, phylogenetic and protein structural features. We report the first examples of full-length, amdoparvovirus-derived EPVs in the genome of the Transcaucasian mole vole (Ellobius lutescens). We also identify four EPVs in mammal and reptile genomes that are intermediate between amdoparvoviruses and their sister genus (Protoparvovirus) in terms of their phylogenetic placement and genomic features. In particular, we identify a genome-length EPV in the genome of a pit viper (Protobothrops mucrosquamatus) that is more similar to a protoparvovirus than an amdoparvovirus in terms of its phylogenetic placement and the structural features of its capsid protein (as revealed by homology modeling), yet exhibits characteristically amdoparvovirus-like genome features including: (1) a putative middle ORF gene; (2) a capsid gene that lacks a phospholipase A2 domain; (3) a genome structure consistent with an amdoparvovirus-like mechanism of capsid gene expression. Our findings indicate that amdoparvovirus host range extends to rodents, and that parvovirus lineages possessing a mixture of proto- and amdoparvovirus-like characteristics have circulated in the past. In addition, we show that EPV sequences in the mole vole and pit viper encode intact, expressible replicase genes that have potentially been co-opted or exapted in these host species
An ancient lineage of highly divergent parvoviruses infects both vertebrate and invertebrate hosts
Chapparvoviruses (ChPVs) comprise a divergent, recently identified group of parvoviruses (family Parvoviridae), associated with nephropathy in immunocompromised laboratory mice and with prevalence in deep sequencing results of livestock showing diarrhea. Here, we investigate the biological and evolutionary characteristics of ChPVs via comparative in silico analyses, incorporating sequences derived from endogenous parvoviral elements (EPVs) as well as exogenous parvoviruses. We show that ChPVs are an ancient lineage within the Parvoviridae, clustering separately from members of both currently established subfamilies. Consistent with this, they exhibit a number of characteristic features, including several putative auxiliary protein-encoding genes, and capsid proteins with no sequence-level homology to those of other parvoviruses. Homology modeling indicates the absence of a β-A strand, normally part of the luminal side of the parvoviral capsid protein core. Our findings demonstrate that the ChPV lineage infects an exceptionally broad range of host species, including both vertebrates and invertebrates. Furthermore, we observe that ChPVs found in fish are more closely related to those from invertebrates than they are to those of amniote vertebrates. This suggests that transmission between distantly related host species may have occurred in the past and that the Parvoviridae family can no longer be divided based on host affiliation
Full genome analysis of four circoviruses newly detected in lower vertebrates (fishes, frogs and a turtle)
Random sampling of squamate reptiles in Spanish natural reserves reveals the presence of novel adenoviruses in lacertids (Family Lacertidae) and worm lizards (Amphisbaenia)
Here, we report the results of a large-scale PCR survey on the prevalence and diversity of adenoviruses (AdVs) in samples collected randomly from free-living reptiles. On the territories of the Guadarrama Mountains National Park in Central Spain and of the Chafarinas Islands in North Africa, cloacal swabs were taken from 318 specimens of eight native species representing five squamate reptilian families. The healthy-looking animals had been captured temporarily for physiological and ethological examinations, after which they were released. We found 22 AdV-positive samples in representatives of three species, all from Central Spain. Sequence analysis of the PCR products revealed the existence of three hitherto unknown AdVs in 11 Carpetane rock lizards (Iberolacerta cyreni), nine Iberian worm lizards (Blanus cinereus), and two Iberian green lizards (Lacerta schreiberi), respectively. Phylogeny inference showed every novel putative virus to be a member of the genus Atadenovirus. This is the very first description of the occurrence of AdVs in amphisbaenian and lacertid hosts. Unlike all squamate atadenoviruses examined previously, two of the novel putative AdVs had A+T rich DNA, a feature generally deemed to mirror previous host switch events. Our results shed new light on the diversity and evolution of atadenoviruses.The authors gratefully acknowledge the financial support provided by the Hungarian Scientific Research Fund (OTKA grant K100163) and by the projects MICIIN-CGL2011-24150/BOS and MINECO CGL2014-53523-P.Peer Reviewe
A pathogenitásért és az állati sejtek manipulálásáért felelős, új adenovírus fehérjék keresése = Search for novel adenovirus proteins responsible for pathogenicity and the manipulation of animal cells
Az adenovírusok sejtreceptorokhoz történő kapcsolódásában részt vevő kapszidfehérjék (a pentonbázis és fiberfej) határozzák meg a vírus szöveti és sejt-specificitását. A sejtek manipulálásáért és az adenovírusok kórokozó képességéért azonban alapvetően a korai kifejeződésű gének által kódolt fehérjék felelősek. Eddig ismeretlen adenovírusokat találva főleg hüllőkben, vadmadarakban, rágcsálókban, denevérekben és majmokban, valamint vírusgenom szekvenálást és elemzést végezve (pl. teljes hal-, gyík-, liba-, egér-, denevér-, majom- és humán adenovírus genomok) számos feltehetően korai, új gén létezését sikerült kimutatni. Vizsgáltuk az ezek által kódolt fehérjék evolúcióját, sokféleségét, változékonyságát, természetes mutáció okozta rövidülését, delécióját vagy duplikációját, a sejtreceptor-kötő helyek meglétét vagy hiányát. A hal-adenovírus feltételezett szulfotranszferáz homológjának génjét és több állati adenovírusból a fiberfejet kódoló génszakaszt bakteriális kifejező rendszerbe klónoztuk és teszteltük kifejeződésüket. Következtetéseket vontunk le a vizsgált gének funkciójára, esetleges nélkülözhetőségükre, valamint az egyes vírusok között megfigyelhető pathogenitási és más biológiai különbségek okára vonatkozóan. | The capsid proteins (penton base and the fiber knob), which take part in the attachment to the cellular receptors, play crucial role in the organ and tissue tropism of adenoviruses. Nonetheless, the proteins coded by the early genes are primarily responsible for the manipulation of cells and for the pathogenicity of these viruses. By finding novel adenoviruses mainly in reptiles, wild birds, rodents, bats and monkeys, and by sequencing and analysing adenovirus genomes (e.g., the full genome of the sturgeon, lizard, goose, mouse, bat, monkey and human adenoviruses), the existence of numerous such supposedly early genes was revealed. We studied the evolution, diversity, variability, truncation caused by natural mutation, deletion, duplication of these proteins as well as the presence or lack of cellular receptor binding sites. The gene of a sulfotransferase homologue of sturgeon adenovirus and gene fragments coding the fiber knobs of several animal adenoviruses were cloned and expressed in bacterial expression systems. We drew several conclusions concerning the function, possible non-essential status of these genes, and the reason for the observed differences in the pathogenicity and other biological properties of the adenoviruses examined
A Drosophila melanogaster sejtes immunitása = The cellular immunity of Drosophila melanogaster
A Drosophila sejtközvetítette immunválaszának szabályozását vizsgáltuk valamint molekuláris immunológiai és genetikai ismeretek elsajátítását és projekt építését tettük lehetővé a tudomány iránt érdeklődő diákok és kutatók számára.Adult Drosophila vérsejtjeire, makrofágokra és a lamellocitákra jellemző markereket azonosítottunk.Az L5 antigén a lamellociták differenciálódásának a szuppresszora.A P1 antigénről (Nimród) megállapítottuk, hogy részt vesz a fagocitózisban.A P1 molekula jellegzetes motívumot hordoz (Nim-repeat),mely egy szupercsaládot határoz meg:tagjai a kódoló gén közvetlen környezetében helyezkednek el. Javaslatot tettünk a Nim repeat kialakulásának a modelljére,leírtuk a Nimród szuprcsalád lehetséges evolúcióját.A vérképzést és a vérsejtek funkcióit szabályozó géneket és molekulákat azonosítottunk.Egy epigenetikus regulátorról megállapítottuk,hogy a vérsejtek osztódását,egy mestergénről pedig,hogy a lamellociták differenciálódását szabályozza.RNSi mutánsgyűjteményben a szesszilis szövet kialakulásában résztvevő génterméket azonosítottunk.Megállapítottuk, hogy a lamellociták a szesszilis szövetből származnak,effektorsejtekké történő differenciálódásuk lépései immunológiai markerekkel nyomonkövethetők.Eddig nem ismert sejteket találtunk Drosophila fajokban és a jellemzésükre alkalmas immunológiai markereket azonosítottunk.Az általunk felismert markereket a Drosophila vérsejt-differenciálódását és funkcióit vizsgáló laboratóriumokban rutinszerűen használják. | We studied the regulation cellular immunity of Drosophila and developed a training-unit based on the research and teaching experience of our multidisciplinary team, with a broad interest in molecular immunology. Results: We identified markers for embryonic macrophages, lamellocytes and blood cells of the adult fly. We described the L5 antigen as a suppressor of lamellocyte development. We defined P1 antigen (Nimrod) as a phagocytosis receptor with a structurally and phylogenetically conserved characteristic unit, the Nim repeat. The repeat defines a superfamily with members located in the close proximity of the p1 gene. We suggested a model for the origin of the Nim repeat, and described the possible evolution of the superfamily. We defined an epigenetic regulator of blood cell differentiation and a master gene regulating the development of lamellocytes. We defined the sessile hematopoietic tissue as the source of lamellocytee precursors. We characterized sequential events in lamellocyte development from sessile stem cells to mature lamellocytes by sequential expression of lamellocyte antigens. We found so far undefined cell types in Drosophila species and developed immunological markers for them. The hemocyte markers defined in our laboratory are used worldwide routinely in studies of blood cell development and function in Drosophila