scholarly journals Polydnavirus Innexins Disrupt Host Cellular Encapsulation and Larval Maturation

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1621
Author(s):  
Peng Zhang ◽  
Matthew Turnbull
Keyword(s):  
Heliothis Virescens ◽  
Recombinant Baculovirus ◽  
Parasitoid Wasp ◽  
Gene Families ◽  
Host Susceptibility ◽  
Recombinant Baculoviruses ◽  
Susceptible Host ◽  
Severe Pathology ◽  
Dsdna Viruses ◽  
Insight Into

Polydnaviruses are dsDNA viruses associated with endoparasitoid wasps. Delivery of the virus during parasitization of a caterpillar and subsequent virus gene expression is required for production of an amenable environment for parasitoid offspring development. Consequently, understanding of Polydnavirus gene function provides insight into mechanisms of host susceptibility and parasitoid wasp host range. Polydnavirus genes predominantly are arranged in multimember gene families, one of which is the vinnexins, which are virus homologues of insect gap junction genes, the innexins. Previous studies of Campoletis sonorensis Ichnovirus Vinnexins using various heterologous systems have suggested the four encoded members may provide different functionality in the infected caterpillar host. Here, we expressed two of the members, vnxG and vnxQ2, using recombinant baculoviruses in susceptible host, the caterpillar Heliothis virescens. Following intrahemocoelic injections, we observed that >90% of hemocytes (blood cells) were infected, producing recombinant protein. Larvae infected with a vinnexin-recombinant baculovirus exhibited significantly reduced molting rates relative to larvae infected with a control recombinant baculovirus and mock-infected larvae. Similarly, larvae infected with vinnexin-recombinant baculoviruses were less likely to survive relative to controls and showed reduced ability to encapsulate chromatography beads in an immune assay. In most assays, the VnxG protein was associated with more severe pathology than VnxQ2. Our findings support a role for Vinnexins in CsIV and more broadly Ichnovirus pathology in infected lepidopteran hosts, particularly in disrupting multicellular developmental and immune physiology.

scholarly journals Ectopic Expression of Virus Innexins in Heliothis virescens Disrupts Hemocyte-Mediated Encapsulation and Host Viability

2019 ◽  
Author(s):  
Peng Zhang ◽  
Matthew W Turnbull
Keyword(s):  
Gene Family ◽  
Gap Junction ◽  
Host Range ◽  
Heliothis Virescens ◽  
Genome Structure ◽  
Ectopic Expression ◽  
Recombinant Baculovirus ◽  
Gene Families ◽  
Recombinant Baculoviruses ◽  
Susceptible Host

1.AbstractPolydnaviruses are dsDNA viruses associated with endoparasitoid wasps. Delivery of the virus during parasitization of a caterpillar and subsequent virus gene expression is required for production of an amenable environment for parasitoid offspring development. Consequently, understanding of Polydnavirus gene function provides insight into mechanisms of host susceptibility and parasitoid wasp host range. Polydnavirus genes predominantly are arranged in multimember gene families, one of which is the vinnexins, which are virus homologues of insect gap junction genes, the innexins. Previous studies of Campoletis sonorensis Ichnovirus Vinnexins using various heterologous systems have suggested the four encoded members may provide different functionality in the infected caterpillar host. Here, we expressed two of the members, vnxG and vnxQ2, using recombinant baculoviruses in susceptible host, the caterpillar Heliothis virescens. Following intrahemocoelic injections, we observed >90% of hemocytes (blood cells) were infected, producing recombinant protein. Larvae infected with a vinnexin-recombinant baculovirus exhibited significantly reduced molting rates relative to larvae infected with a control recombinant baculovirus and mock infected larvae. Similarly, larvae infected with vinnexin-recombinant baculoviruses were less likely to molt relative to controls, and showed reduced ability to encapsulate chromatography beads in an immune assay. In most assays, the VnxG protein was associated with more severe pathology than VnxQ2. These results, in light of previous findings, support that Polydnavirus Vinnexin gene family members may provide complementary, rather than redundant, effects. This in turn indicates a need to test gene family member functionality across infected hosts for effects to determine member contribution to host range.2.ImportancePolydnaviruses are obligate mutualistic associates of highly speciose wasp taxa that parasitize caterpillars. Expression of Polydnavirus-encoded genes in hosts parasitized by wasps is necessary for successful parasitization, and an unusual genome structure including multiple-membered gene families is hypothesized to contribute to host manipulation. We have tested this hypothesis by in vivo expression of two members of a family of Polydnavirus homologues of Innexins, or insect gap junction proteins. Previous findings demonstrated that the two Vinnexins induce different physiological alterations in heterologous systems. Here, in host caterpillars, we observed differential alteration by the two proteins of host immune cell (hemocyte) bioelectrical physiology and the immune response of encapsulation. Not only do our data suggest a linkage between cellular bioelectricity and immunity in insects, but they support that gene family expansion has functional consequences to both Polydnavirus and host wasp success.

scholarly journals Dually Functional Recombinant Baculovirus Expressing Both the Excitatory and Depressant Insect Selective Neurotoxins

1993 ◽  
Author(s):  
Nor Chejanovsky ◽  
Bruce D. Hammock ◽  
Eliahu Zlotkin ◽  
Michael Gurevitz
Keyword(s):  
Insecticidal Activity ◽  
Heliothis Virescens ◽  
Recombinant Baculovirus ◽  
Scorpion Venom ◽  
Recombinant Baculoviruses ◽  
Recombinant Viruses ◽  
Combined Application ◽  
Insect Toxins ◽  
Insect Toxin ◽  
The Impact

The present project is aimed to improve the insecticidal potency of baculoviruses, to American and Israeli lepidopterous pests of Spodoptera and Heliothis species, by engineering recombinant baculoviruses expressing anti-insect toxins derived from scorpion venom. Through this study were isolated recombinant Autographa california M Nucleopolyhedroviruses (AcNPVs) which expressed alpha (LqhaIT), excitatory (AaIT, LqhIT1 and LqhIT3) and depressant (LqhIT2) anti-insect neurotoxins. Bioassays on Heliothis species (Helicoverpa armigera and Heliothis virescens) were employed to assess the potency of the viruses. The recombinant viruses possessed an enhanced speed of kill compared to wild type AcNPV. Recombinant AcNPVs expressing the depressant toxins emerged as appealing improved baculoviruses. Applied combinations of alpha, excitatory and depressant toxins enhanced their insecticidal activity against blowfly and lepidopterous larvae. Moreover, combined application of recombinant AcNPVs expressing LqhaIT and AaIT possessed increased insecticidal activity compared to single applications of them. A reduced growth rate of H. virescens larvae was obtained by comparing the larvae infected with recombinant AcNPV expressing AaIT under the control of the AcNPV early ie1 to the very late p10 promoters. Through this project improved protocols and methods were developed to purify and bioassay the anti-insect toxins and their correspondent recombinant baculoviruses. A novel highly potent anti-insect toxin Aa IT5 was isolated and characterized. Finally, the impact of use of recombinant baculoviruses, expressing anti-insect scorpion neurotoxins to non-target insects, was evaluated.

scholarly journals The draft genome of the specialist flea beetle Altica viridicyanea (Coleoptera: Chrysomelidae)

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Huai-Jun Xue ◽  
Yi-Wei Niu ◽  
Kari A. Segraves ◽  
Rui-E Nie ◽  
Ya-Jing Hao ◽  
...  
Keyword(s):  
Host Plant ◽  
Plant Cell Wall ◽  
Flea Beetle ◽  
Repetitive Sequences ◽  
Draft Genome ◽  
Gene Families ◽  
Ecological Speciation ◽  
Secondary Chemistry ◽  
Host Plant Specialization ◽  
Insight Into

Abstract Background Altica (Coleoptera: Chrysomelidae) is a highly diverse and taxonomically challenging flea beetle genus that has been used to address questions related to host plant specialization, reproductive isolation, and ecological speciation. To further evolutionary studies in this interesting group, here we present a draft genome of a representative specialist, Altica viridicyanea, the first Alticinae genome reported thus far. Results The genome is 864.8 Mb and consists of 4490 scaffolds with a N50 size of 557 kb, which covered 98.6% complete and 0.4% partial insect Benchmarking Universal Single-Copy Orthologs. Repetitive sequences accounted for 62.9% of the assembly, and a total of 17,730 protein-coding gene models and 2462 non-coding RNA models were predicted. To provide insight into host plant specialization of this monophagous species, we examined the key gene families involved in chemosensation, detoxification of plant secondary chemistry, and plant cell wall-degradation. Conclusions The genome assembled in this work provides an important resource for further studies on host plant adaptation and functionally affiliated genes. Moreover, this work also opens the way for comparative genomics studies among closely related Altica species, which may provide insight into the molecular evolutionary processes that occur during ecological speciation.

scholarly journals C. elegans provide milk for their young

2020 ◽  
Author(s):  
Carina C. Kern ◽  
StJohn Townsend ◽  
Antoine Salzmann ◽  
Nigel B. Rendell ◽  
Graham W. Taylor ◽  
...  
Keyword(s):  
Sexual Maturity ◽  
Reproductive Effort ◽  
Pacific Salmon ◽  
Resource Transfer ◽  
C Elegans ◽  
Destructive Process ◽  
Severe Pathology ◽  
Intestinal Atrophy ◽  
Insight Into

AbstractAdult C. elegans hermaphrodites exhibit severe senescent pathology that begins to develop within days of reaching sexual maturity (Ezcurra et al., 2018; Garigan et al., 2002; Herndon et al., 2002; Wang et al., 2018). For example, after depletion of self-sperm, intestinal biomass is converted into yolk leading to intestinal atrophy and yolk steatosis (pseudocoelomic lipoprotein pools, PLPs) (Ezcurra et al., 2018; Garigan et al., 2002; Herndon et al., 2002; Sornda et al., 2019). These senescent pathologies are promoted by insulin/IGF-1 signalling (IIS), which also shortens lifespan (Ezcurra et al., 2018; Kenyon, 2010). This pattern of rapid and severe pathology in organs linked to reproduction is reminiscent of semelparous organisms where massive reproductive effort leads to rapid death (reproductive death) as in Pacific salmon (Finch, 1990; Gems et al., 2020). Moreover, destructive conversion of somatic biomass to support reproduction is a hallmark of reproductive death (Gems et al., 2020). Yet arguing against the occurrence of reproductive death in C. elegans is the apparent futility of post-reproductive yolk production. Here we show that this effort is not futile, since post-reproductive mothers vent yolk through their vulva, which is consumed by progeny and supports their growth; thus vented yolk functions as a milk, and C. elegans mothers exhibit a form of lactation. Moreover, IIS promotes lactation, thereby effecting a costly process of resource transfer from postreproductive mothers to offspring. These results support the view that C. elegans hermaphrodites exhibit reproductive death involving a self-destructive process of lactation that is promoted by IIS. They also provide new insight into how the strongly life-shortening effects of IIS in C. elegans evolved.

scholarly journals Genome-Wide Identification of CBL-CIPK Gene Family in Honeysuckle (Lonicera japonica Thunb.) and Their Regulated Expression Under Salt Stress

2021 ◽  
Vol 12 ◽  
Author(s):  
Luyao Huang ◽  
Zhuangzhuang Li ◽  
Qingxia Fu ◽  
Conglian Liang ◽  
Zhenhua Liu ◽  
...  
Keyword(s):  
Salt Stress ◽  
Protein Kinases ◽  
Stress Responses ◽  
Structure Prediction ◽  
Functional Divergence ◽  
Gene Families ◽  
Plant Responses ◽  
Interacting Protein ◽  
Protein Motifs ◽  
Insight Into

In plants, calcineurin B-like proteins (CBLs) are a unique group of Ca2+ sensors that decode Ca2+ signals by activating a family of plant-specific protein kinases known as CBL-interacting protein kinases (CIPKs). CBL-CIPK gene families and their interacting complexes are involved in regulating plant responses to various environmental stimuli. To gain insight into the functional divergence of CBL-CIPK genes in honeysuckle, a total of six LjCBL and 17 LjCIPK genes were identified. The phylogenetic analysis along with the gene structure analysis divided both CBL and CBL-interacting protein kinase genes into four subgroups and validated by the distribution of conserved protein motifs. The 3-D structure prediction of proteins shown that most LjCBLs shared the same Protein Data Bank hit 1uhnA and most LjCIPKs shared the 6c9Da. Analysis of cis-acting elements and gene ontology implied that both LjCBL and LjCIPK genes could be involved in hormone signal responsiveness and stress adaptation. Protein-protein interaction prediction suggested that LjCBL4 is hypothesized to interact with LjCIPK7/9/15/16 and SOS1/NHX1. Gene expression analysis in response to salinity stress revealed that LjCBL2/4, LjCIPK1/15/17 under all treatments gradually increased over time until peak expression at 72 h. These results demonstrated the conservation of salt overly sensitive pathway genes in honeysuckle and a model of Ca2+-LjCBL4/LjSOS3-LjCIPK16/LjSOS2 module-mediated salt stress signaling in honeysuckle is proposed. This study provides insight into the characteristics of the CBL-CIPK gene families involved in honeysuckle salt stress responses, which could serve as a foundation for gene transformation technology, to obtain highly salt-tolerant medicinal plants in the context of the global reduction of cultivated land.

scholarly journals Cotesia congregata Bracovirus Circles Encoding PTP and Ankyrin Genes Integrate into the DNA of Parasitized Manduca sexta Hemocytes

2018 ◽  
Vol 92 (15) ◽  
Author(s):  
Germain Chevignon ◽  
Georges Periquet ◽  
Gabor Gyapay ◽  
Nathalie Vega-Czarny ◽  
Karine Musset ◽  
...  
Keyword(s):  
Manduca Sexta ◽  
High Throughput Sequencing ◽  
Particle Production ◽  
Parasitoid Wasp ◽  
Gene Families ◽  
Parasitoid Wasps ◽  
Content Type ◽  
Virulence Proteins ◽  
Cotesia Congregata ◽  
Dividing Cells

ABSTRACT Polydnaviruses (PDVs) are essential for the parasitism success of tens of thousands of species of parasitoid wasps. PDVs are present in wasp genomes as proviruses, which serve as the template for the production of double-stranded circular viral DNA carrying virulence genes that are injected into lepidopteran hosts. PDV circles do not contain genes coding for particle production, thereby impeding viral replication in caterpillar hosts during parasitism. Here, we investigated the fate of PDV circles of Cotesia congregata bracovirus during parasitism of the tobacco hornworm, Manduca sexta, by the wasp Cotesia congregata. Sequences sharing similarities with host integration motifs (HIMs) of Microplitis demolitor bracovirus (MdBV) circles involved in integration into DNA could be identified in 12 CcBV circles, which encode PTP and VANK gene families involved in host immune disruption. A PCR approach performed on a subset of these circles indicated that they persisted in parasitized M. sexta hemocytes as linear forms, possibly integrated in host DNA. Furthermore, by using a primer extension capture method based on these HIMs and high-throughput sequencing, we could show that 8 out of 9 circles tested were integrated in M. sexta hemocyte genomic DNA and that integration had occurred specifically using the HIM, indicating that an HIM-mediated specific mechanism was involved in their integration. Investigation of BV circle insertion sites at the genome scale revealed that certain genomic regions appeared to be enriched in BV insertions, but no specific M. sexta target site could be identified. IMPORTANCE The identification of a specific and efficient integration mechanism shared by several bracovirus species opens the question of its role in braconid parasitoid wasp parasitism success. Indeed, results obtained here show massive integration of bracovirus DNA in somatic immune cells at each parasitism event of a caterpillar host. Given that bracoviruses do not replicate in infected cells, integration of viral sequences in host DNA might allow the production of PTP and VANK virulence proteins within newly dividing cells of caterpillar hosts that continue to develop during parasitism. Furthermore, this integration process could serve as a basis to understand how PDVs mediate the recently identified gene flux between parasitoid wasps and Lepidoptera and the frequency of these horizontal transfer events in nature.

scholarly journals Biased expression of JH-proximal VH genes occurs in the newly generated repertoire of neonatal and adult mice.

1990 ◽  
Vol 171 (3) ◽  
pp. 843-859 ◽  
Author(s):  
B A Malynn ◽  
G D Yancopoulos ◽  
J E Barth ◽  
C A Bona ◽  
F W Alt
Keyword(s):  
Gene Families ◽  
Relative Expression ◽  
Immunodeficient Mice ◽  
Regulatory Interactions ◽  
Adult Mice ◽  
Neonatal Liver ◽  
Vh Gene ◽  
Vh Genes ◽  
Adult Bone ◽  
Insight Into

We have previously demonstrated a dramatic preference for utilization of the most JH-proximal VH gene segments in the newborn liver versus adult spleen. We now examine in detail the relative expression of different VH gene families throughout ontogeny and in immunodeficient mice to gain insight into factors that cause the shift in VH usage. We find that the relative expression of VH gene families remains constant and biased throughout fetal and neonatal liver development. In addition, the primary VH repertoire expressed in neonatal spleen displays a similarly biased, position-dependent VH repertoire. The pattern of VH gene expression begins to change at 5-7 d postnatally and reaches the adult randomized pattern at approximately 2 wk of age. We also find biased expression of JH-proximal VH gene families in adult bone marrow and in spleens of adult leaky scid mice, suggesting that the spontaneously generated repertoire of adult mice is similar to that observed in neonates. Together, these data suggest that a position-dependent repertoire is generated in differentiating pre-B cells at all stages of ontogeny, at least in part, as a result of preferential rearrangement of proximal VH gene segments. Therefore, mechanisms subsequent to V gene rearrangement, such as regulatory interactions and antigen selection, must play a major role in normalizing the repertoire.

scholarly journals The chromosome-scale reference genome of black pepper provides insight into piperine biosynthesis

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Lisong Hu ◽  
Zhongping Xu ◽  
Maojun Wang ◽  
Rui Fan ◽  
Daojun Yuan ◽  
...  
Keyword(s):  
Reference Genome ◽  
Gene Families ◽  
Black Pepper ◽  
Piper Nigrum ◽  
Comparative Genomic ◽  
Specific Gene ◽  
Phylogenomic Analysis ◽  
Genomic Analyses ◽  
Species Specific ◽  
Insight Into

Abstract Black pepper (Piper nigrum), dubbed the ‘King of Spices’ and ‘Black Gold’, is one of the most widely used spices. Here, we present its reference genome assembly by integrating PacBio, 10x Chromium, BioNano DLS optical mapping, and Hi-C mapping technologies. The 761.2 Mb sequences (45 scaffolds with an N50 of 29.8 Mb) are assembled into 26 pseudochromosomes. A phylogenomic analysis of representative plant genomes places magnoliids as sister to the monocots-eudicots clade and indicates that black pepper has diverged from the shared Laurales-Magnoliales lineage approximately 180 million years ago. Comparative genomic analyses reveal specific gene expansions in the glycosyltransferase, cytochrome P450, shikimate hydroxycinnamoyl transferase, lysine decarboxylase, and acyltransferase gene families. Comparative transcriptomic analyses disclose berry-specific upregulated expression in representative genes in each of these gene families. These data provide an evolutionary perspective and shed light on the metabolic processes relevant to the molecular basis of species-specific piperine biosynthesis.

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