| genome organization of the chelonus inanitus polydnavirus: excision sites, spacers and abundance of proviral and excised segments. | polydnaviruses are only found in symbiotic association with parasitic wasps within the families ichneumonidae and braconidae (ichnoviruses and bracoviruses). they have a segmented genome consisting of circular double-stranded dna. in the proviral linear form they are integrated in the wasp's genome; in two bracoviruses, segments were found to be clustered. proviral segments have direct terminal repeats. segment excision has been proposed to occur through juxtaposition of these repeats by formati ... | 2007 | 17251562 |
| identification of bracovirus particle proteins and analysis of their transcript levels at the stage of virion formation. | polydnaviruses (pdvs) are unique symbiotic viruses associated with parasitic wasps; they replicate only in the calyx cells of a wasp's ovaries and are transferred at oviposition along with the parasitoid egg into the lepidopteran host. the dna packaged in the viral particles encodes factors that manipulate the host's immune defences and development to benefit the parasitoid. pdvs are found in two subfamilies of ichneumonids (ichnoviruses) and in braconids of the microgastroid complex (bracovirus ... | 2010 | 20554796 |
| the venom composition of the parasitic wasp chelonus inanitus resolved by combined expressed sequence tags analysis and proteomic approach. | parasitic wasps constitute one of the largest group of venomous animals. although some physiological effects of their venoms are well documented, relatively little is known at the molecular level on the protein composition of these secretions. to identify the majority of the venom proteins of the endoparasitoid wasp chelonus inanitus (hymenoptera: braconidae), we have randomly sequenced 2111 expressed sequence tags (ests) from a cdna library of venom gland. in parallel, proteins from pure venom ... | 2010 | 21138570 |
| response of immunocompetent and immunosuppressed spodoptera littoralis larvae to baculovirus infection. | the mediterranean lepidopteran pest spodoptera littoralis is highly resistant to infection with the autographa californica multiple nucleopolyhedrovirus (acmnpv) via the oral route, but highly sensitive to infection with budded virus (bv) via the intrahaemocoelic route. to study the fate of acmnpv infection in s. littoralis, vhsgfp, an acmnpv recombinant that expresses the reporter green fluorescent protein gene under the control of the drosophila heat-shock promoter, and high-resolution fluores ... | 2006 | 16847117 |
| stage-dependent expression of chelonus inanitus polydnavirus genes in the host and the parasitoid. | chelonus inanitus (braconidae) is a solitary egg-larval parasitoid of spodoptera littoralis (noctuidae). along with the egg it also injects polydnaviruses (civ) and venom, which are prerequisites for successful parasitoid development. civ protects the parasitoid from encapsulation by the host's immune system and induces a developmental arrest in the prepupal stage. the polydnavirus genome consists of several double-stranded circular dna segments. proviral dna is integrated in the wasp's genome a ... | 2004 | 15607504 |
| characterization of two genes of the polydnavirus of chelonus inanitus and their stage-specific expression in the host spodoptera littoralis. | chelonus inanitus (braconidae, hymenoptera) is a solitary egg-larval parasitoid of spodoptera littoralis. along with the egg the female wasp injects polydnaviruses, which are prerequisites for successful parasitoid development. the polydnavirus genome is segmented and consists of double-stranded circular dna. proviral dna is integrated in the wasp's genome; virus replication is restricted to the wasp's ovary and does not occur in the parasitized host. the polydnavirus of c. inanitus (civ) protec ... | 2002 | 11961262 |
| characterization of chelonus inanitus polydnavirus segments: sequences and analysis, excision site and demonstration of clustering. | polydnaviruses (genera ichnovirus and bracovirus) have a segmented genome of circular double-stranded dna molecules, replicate in the ovary of parasitic wasps and are essential for successful parasitism of the host. here we show the first detailed analysis of various segments of a bracovirus, the chelonus inanitus virus (civ). four segments were sequenced and two of them, civ12 and civ14, were found to be closely related while civ14.5 and civ16.8 were unrelated. civ12, civ14.5 and civ16.8 are un ... | 2002 | 11752722 |
| polydnavirus of the parasitic wasp chelonus inanitus (braconidae): characterization, genome organization and time point of replication. | ultrastructural analysis of the polydnavirus of the braconid wasp chelonus inanitus revealed that virions consist of one cylindrical nucleocapsid enveloped by a single unit membrane. nucleocapsids have a constant diameter of 33.7 +/- 1.4 nm and a variable length of between 8 and 46 nm. spreading of viral dna showed that the genome consists of circular dsdna molecules of variable sizes and measurement of the contour lengths indicated sizes of between 7 and 31 kbp. when virions were exposed to osm ... | 1994 | 7996130 |
| ovary development and polydnavirus morphogenesis in the parasitic wasp chelonus inanitus. ii. ultrastructural analysis of calyx cell development, virion formation and release. | polydnaviruses are unique symbiotic viruses that are formed only in calyx cells in the ovary of parasitic wasps in the families braconidae and ichneumonidae; accordingly, two genera, bracovirus and ichnovirus are recognized. we have presented a detailed ultrastructural analysis of ovary and calyx cell differentiation and virion morphogenesis, together with the first data on virion release in a bracovirus. differentiation of the ovary into germarium/vitellarium and the calyx region begins immedia ... | 2003 | 12692280 |
| overview of parasitism associated effects on host haemocytes in larval parasitoids and comparison with effects of the egg-larval parasitoid chelonus inanitus on its host spodoptera littoralis. | in the first part we review the effects of larval endoparasitoids and their polydnavirus and venom on the immune system of their hosts. in all systems investigated, haemocyte spreading and encapsulation activity was reduced; in some cases effects on total (thc) or differential (dhc) haemocyte count as well as modification of haemocyte morphology and ultrastructure were also documented. in many cases polydnavirus (and venom) were shown to play a major role in abrogation of the host's immune react ... | 1998 | 12769877 |
| physiological and endocrine changes associated with polydnavirus/venom in the parasitoid-host system chelonus inanitus-spodoptera littoralis. | as shown earlier, parasitization by the egg-larval parasitoid c. inanitus causes in its host the precocious onset of metamorphosis in the 5th instar followed by developmental arrest in the prepupal stage. polydnavirus/venom were shown to be responsible for the developmental arrest. we investigated how polydnavirus/venom affect growth of the host larvae and found that head capsule widths were smaller from the 4th to 6th stadium and weights were lower in the 6th stadium in polydnavirus/venom-conta ... | 1998 | 12769965 |
| characterization of a 212kd protein, released into the host by the larva of the endoparasitoid chelonus inanitus (hymenoptera, braconidae). | previous studies have shown that the larva of chelonus inanitus plays an essential role in inducing the precocious onset of metamorphosis in polydnavirus/venom-containing spodoptera littoralis, and that this effect might be due to proteins released by the parasitoid larva into the host. here we show that a 212kd protein is the predominant protein released in vitro by late first instar parasitoids. this protein does not accumulate anywhere in the parasitoid body. polyclonal antibodies specific fo ... | 2001 | 12770184 |
| analysis of endoparasitoid-released proteins and their effects on host development in the system chelonus inanitus (braconidae)-spodoptera littoralis (noctuidae). | having shown earlier that the larva of c. inanitus is essential in inducing the precocious onset of metamorphosis in polydnavirus/venom containing s. littoralis, we here analysed release of proteins by parasitoid larvae and their effects on host development. parasitoid larvae released proteins in vivo and in vitro in a stage dependent manner. an approximately 212 kd protein was released from the mid 1st instar onwards and additional smaller proteins could be associated mainly with the 2nd and 3r ... | 1999 | 12770295 |
| titres of juvenile hormone i, ii and iii in spodoptera littoralis (noctuidae) from the egg to the pupal moult and their modification by the egg-larval parasitoid chelonus inanitus (braconidae). | physico-chemical analysis of juvenile hormones (jhs) of spodoptera littoralis revealed highest quantities in the second half of embryonic development and in newly hatched 1st instar larvae. at these stages, mostly jh ii, jh i and little jh iii were found, while in later stages only jh ii and jh iii were found. titres fluctuated in a similar manner in all larval instars, being lowest during the moults. in last (=6th) instar larvae, jhs disappeared in the late feeding-digging stage and again incre ... | 1999 | 12770366 |
| fate of polydnavirus dna of the egg-larval parasitoid chelonus inanitus in the host spodoptera littoralis. | in situ hybridizations show that 5 min after parasitization, polydnavirus dna is in close vicinity of the parasitoid egg, but 5 h later also in the yolk and partially in the host embryo. fifteen hours after parasitization, the viral dna is seen all over the host embryo and hardly in the yolk. the tissue distribution of the viral dna was analysed and quantified by dot blots in the fifth instar parasitized larvae. on a per host basis, haemocytes and fat body contained the highest amount of viral d ... | 2003 | 12770628 |
| stage-dependent strategies of host invasion in the egg-larval parasitoid chelonus inanitus. | chelonus inanitus (braconidae) is a solitary egg-larval parasitoid which lays its eggs into eggs of spodoptera littoralis (noctuidae); the parasitoid larva then develops in the haemocoel of the host larva. host embryonic development lasts approx. 3.5 days while parasitoid embryonic development lasts approx. 16 h. all stages of host eggs can be successfully parasitized, and we show here that either the parasitoid larva or the wasp assures that the larva eventually is located in the host's haemoco ... | 2005 | 15749111 |
| cloning, characterization and analysis by rna interference of various genes of the chelonus inanitus polydnavirus. | successful parasitism of some endoparasitic wasps depends on an obligately symbiotic association with polydnaviruses. these unique viruses have a segmented genome consisting of circles of double-stranded (ds) dna and do not replicate in the parasitized host. they are produced in the wasp's ovary and injected into the host along with the egg. chelonus inanitus is an egg-larval parasitoid; its polydnavirus (civ) has been shown to protect the parasitoid larva from the host's immune system and to in ... | 2005 | 15784890 |
| changes in the haemolymph proteome of spodoptera littoralis induced by the parasitoid chelonus inanitus or its polydnavirus and physiological implications. | the egg-larval parasitoid chelonus inanitus induces in its host spodoptera littoralis two major developmental effects, namely a precocious onset of metamorphosis followed by a developmental arrest in the prepupal stage. along with each egg, the wasp injects polydnavirus and venom into the host egg. the polydnavirus has been shown to play a major role in inducing the developmental arrest while the parasitoid larva is instrumental in inducing the precocious onset of metamorphosis. here we report t ... | 2005 | 15936028 |
| influence of the parasitoid chelonus inanitus and its polydnavirus on host nutritional physiology and implications for parasitoid development. | chelonus inanitus is a solitary egg-larval endoparasitoid, which feeds on host haemolymph during its internal phase. parasitization induces in the host spodoptera littoralis a precocious onset of metamorphosis and a developmental arrest in the prepupal stage. at this stage the parasitoid larva emerges from the host and consumes it. we show here that parasitization and the co-injected polydnaviruses affect the nutritional physiology of the host mainly in the last larval instar. polydnaviruses cau ... | 2005 | 16203013 |
| development of the anal vesicle, salivary glands and gut in the egg-larval parasitoid chelonus inanitus: tools to take up nutrients and to manipulate the host? | larvae of endoparasitoids undergo extensive morphological changes and often have special features to allow their development inside the host. we present the first detailed study on the development of the anal vesicle and the gut. the analyses reveal that the anal vesicle is first seen on the dorsal side of the abdomen as an internal structure covered by a membrane. the morphology of the abdomen then changes intensively: new segments are formed and the anal vesicle develops from a crest of large ... | 2006 | 16386270 |
| transcriptional analysis of polydnaviral genes in the course of parasitization reveals segment-specific patterns. | polydnaviruses are symbiotic viruses of endoparasitic wasps, which are formed in their ovary and injected along with the eggs into the host. they manipulate the host in a way to allow successful parasitoid development. a hallmark of polydnaviruses is their segmented genome consisting of several circles of double-stranded dna. we are studying the solitary egg-larval parasitoid chelonus inanitus (braconidae) parasitizing spodoptera littoralis (noctuidae). the polydnavirus of chelonus inanitus (civ ... | 2007 | 17694561 |
| stage dependent influences of polydnaviruses and the parasitoid larva on host ecdysteroids. | in the solitary egg-larval parasitoid chelonus inanitus (braconidae) both polydnavirus and the parasitoid larva manipulate host development. parasitization leads to a premature drop in juvenile hormone titre and a precocious onset of metamorphosis in the 5th larval instar. the c. inanitus bracovirus (cibv) alone causes a reduction in host ecdysteroid titres at the pupal cell formation stage and prevents pupation. here we report three new findings. (1) we show that parasitization causes a reducti ... | 2009 | 19446562 |
| venom of the egg-larval parasitoid chelonus inanitus is a complex mixture and has multiple biological effects. | the egg-larval parasitoid chelonus inanitus injects bracoviruses (bvs) and venom along with the egg into the host egg; both components are essential for successful parasitoid development. all stages of eggs of its natural host, spodoptera littoralis, can be successfully parasitized, i.e. from mainly a yolk sphere to a fully developed embryo. here, we show that the venom contains at least 25 proteins with masses from 14kda to over 300kda ranging from acidic to basic. the majority is glycosylated ... | 2010 | 20006617 |
| ovary development and polydnavirus morphogenesis in the parasitic wasp chelonus inanitus. i. ovary morphogenesis, amplification of viral dna and ecdysteroid titres. | polydnaviruses are unique symbiotic viruses that are replicated in the calyx cells of the ovary of some parasitic wasps. they have a segmented genome of circular double-stranded dna and are injected along with the wasp's egg into the host, where they are essential for successful parasitism. polydnaviruses replicate from integrated proviral dna, and after excision of viral segments, flanking dna is rejoined. little is known about ovarian morphogenesis, the mode of amplification of the viral dna a ... | 2003 | 12692279 |
| presence of polydnavirus transcripts in an egg-larval parasitoid and its lepidopterous host. | the parasitoid chelonus inanitus (braconidae, hymenoptera) oviposits into eggs of spodoptera littoralis (noctuidae, lepidoptera) and, along with the egg, also injects polydnaviruses and venom, which are prerequisites for successful parasitoid development. the parasitoid larva develops within the embryonic and larval stages of the host, which enters metamorphosis precociously and arrests development in the prepupal stage. polydnaviruses are responsible for the developmental arrest and interfere w ... | 1999 | 10423155 |
| polydnavirus dna of the braconid wasp chelonus inanitus is integrated in the wasp's genome and excised only in later pupal and adult stages of the female. | many endoparasitic wasps inject, along with the egg, polydnavirus into their insect hosts, the virus being a prerequisite for successful parasitoid development. the genome of polydnaviruses consists of multiple circular dsdna molecules of variable size. we show for a 12 kbp segment of the braconid chelonus inanitus (civ12) that it is integrated into the wasp genome. this is the first direct demonstration of integration for a bracovirus. pcr data indicated that the integrated form of civ12 was pr ... | 1996 | 8922483 |
| deep sequencing identifies viral and wasp genes with potential roles in replication of microplitis demolitor bracovirus. | viruses in the genus bracovirus (bv) (polydnaviridae) are symbionts of parasitoid wasps that specifically replicate in the ovaries of females. recent analysis of expressed sequence tags from two wasp species, cotesia congregata and chelonus inanitus, identified transcripts related to 24 different nudivirus genes. these results together with other data strongly indicate that bvs evolved from a nudivirus ancestor. however, it remains unclear whether bv-carrying wasps contain other nudivirus-like g ... | 2012 | 22238295 |
| kaolin and copper-based products applications: ecotoxicology on four natural enemies. | lethal and sublethal effects of kaolin clays and two copper-based products on four natural enemies found in olive orchards anthocoris nemoralis (f.) (hem. anthocoridae), chelonus inanitus (l.) (hym. braconidae), chilocorus nigritus (f.) (col. coccinellidae) and scutellysta cyanea motschulsky (hym. pteromalidae) are described. both kaolin and copper can be applied for controlling the olive fruit fly and the olive moth, two important pests of this crop. the products did not increase the mortality ... | 2013 | 23415488 |