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 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 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 Genome-wide identification of MscS like gene family in Cicer arietinum using bioinformatics approach

2018 ◽  
Vol 7 (2) ◽  
pp. 2002 ◽  
Author(s):  
Noymi Basumatary ◽  
Archana Kumari ◽  
Jatin Sarmah
Keyword(s):  
Subcellular Localization ◽  
Gene Family ◽  
Cicer Arietinum ◽  
Genome Structure ◽  
Evolutionary Relationship ◽  
Chemical Properties ◽  
Gene Families ◽  
Genome Wide ◽  
Physico Chemical ◽  
Structure Annotation

In plants, the mechanosensitive channels have important roles in proprioception, gravity sensing, growth of pollen tube and controlling the shape and size of plastid. In the present study, we performed computational analysis and identified the mechanosensitive channel of small conductance like (MscS) gene family in Cicer arietinum (chickpea). Six Cicer arietinum MscS-like (CaMSL) genes were identified. These six genes were distributed on four different chromosomes. A detailed overview of CaMSL genes in Cicer arietinum is explored by using a total of 33107 proteins from chickpea. On the basis of BLAST analysis, presence of complete ORF and evolutionary relationship we identified 6 genes (named as CaMSL1, CaMSL2, CaMSL3, CaMSL4, CaMSL5 and CaMSL6). Further, the transmembrane regions, subcellular localization, physico-chemical properties, gene structure analysis and genome structure annotation of the identified genes confirmed that the identified genes might act for transmembrane proteins as well as their subcellular localization prediction demonstrated three genes to be located in the plasma membrane, two in the chloroplast membrane, one in the mitochondrion. Thus, further analysis of the data obtained from this study will help to make a baseline to increase the understanding of involvement of MSL gene families in plant growth, development and other functions in C. arietinum.

scholarly journals Isolation and Characterization Of Rice R Genes: Evidence for Distinct Evolutionary Paths in Rice and Maize

Genetics ◽  
1996 ◽  
Vol 142 (3) ◽  
pp. 1021-1031 ◽  
Author(s):  
Jianping Hu ◽  
Beth Anderson ◽  
Susan R Wessler
Keyword(s):  
Gene Family ◽  
Gene Families ◽  
Chromosome 1 ◽  
R Gene ◽  
R Genes ◽  
Helix Loop Helix ◽  
Isolation And Characterization ◽  
Undetermined Function ◽  
Evolutionary Paths

Abstract R and B genes and their homologues encode basic helix-loop-helix (bHLH) transcriptional activators that regulate the anthocyanin biosynthetic pathway in flowering plants. In maize, R/B genes comprise a very small gene family whose organization reflects the unique evolutionary history and genome architecture of maize. To know whether the organization of the R gene family could provide information about the origins of the distantly related grass rice, we characterized members of the R gene family from rice Oryza sativa. Despite being a true diploid, O. sativa has at least two R genes. An active homologue (Ra) with extensive homology with other R genes is located at a position on chromosome 4 previously shown to be in synteny with regions of maize chromosomes 2 and 10 that contain the B and R loci, respectively. A second rice R gene (Rb) of undetermined function was identified on chromosome 1 and found to be present only in rice species with AA genomes. All non-AA species have but one R gene that is Ra-like. These data suggest that the common ancestor shared by maize and rice had a single R gene and that the small R gene families of grasses have arisen recently and independently.

scholarly journals Expression of a gene duplication encoding conserved sperm tail proteins is translationally regulated in Drosophila melanogaster.

1993 ◽  
Vol 13 (3) ◽  
pp. 1708-1718 ◽  
Author(s):  
M Schäfer ◽  
D Börsch ◽  
A Hülster ◽  
U Schäfer
Keyword(s):  
Drosophila Melanogaster ◽  
Gene Family ◽  
Translational Control ◽  
Germ Line ◽  
Gene Families ◽  
Homologous Gene ◽  
Male Sterile ◽  
Sperm Tail ◽  
Repetitive Motif ◽  
Carboxy Terminal

We have analyzed a locus of Drosophila melanogaster located at 98C on chromosome 3, which contains two tandemly arranged genes, named Mst98Ca and Mst98Cb. They are two additional members of the Mst(3)CGP gene family by three criteria. (i) Both genes are exclusively transcribed in the male germ line. (ii) Both transcripts encode a protein with a high proportion of the repetitive motif Cys-Gly-Pro. (iii) Their expression is translationally controlled; while transcripts can be detected in diploid stages of spermatogenesis, association with polysomes can be shown only in haploid stages of sperm development. The genes differ markedly from the other members of the gene family in structure; they do not contain introns, they are of much larger size, and they have the Cys-Gly-Pro motifs clustered at the carboxy-terminal end of the encoded proteins. An antibody generated against the Mst98Ca protein recognizes both Mst98C proteins in D. melanogaster. In a male-sterile mutation in which spermiogenesis is blocked before individualization of sperm, both of these proteins are no longer synthesized. This finding provides proof of late translation for the Mst98C proteins and thereby independent proof of translational control of expression. Northern (RNA) and Western immunoblot analyses indicate the presence of homologous gene families in many other Drosophila species. The Mst98C proteins share sequence homology with proteins of the outer dense fibers in mammalian spermatozoa and can be localized to the sperm tail by immunofluorescence with an anti-Mst98Ca antibody.

scholarly journals Genome-wide search and structural and functional analyses for late embryogenesis-abundant (LEA) gene family in poplar

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Zihan Cheng ◽  
Xuemei Zhang ◽  
Wenjing Yao ◽  
Kai Zhao ◽  
Lin Liu ◽  
...  
Keyword(s):  
Gene Family ◽  
Higher Plants ◽  
Abiotic Stress Tolerance ◽  
Gene Families ◽  
Regulatory Elements ◽  
Late Embryogenesis Abundant ◽  
Genome Wide ◽  
Lea Gene ◽  
Late Embryogenesis ◽  
Genome Wide Search

Abstract Background The Late Embryogenesis-Abundant (LEA) gene families, which play significant roles in regulation of tolerance to abiotic stresses, widely exist in higher plants. Poplar is a tree species that has important ecological and economic values. But systematic studies on the gene family have not been reported yet in poplar. Results On the basis of genome-wide search, we identified 88 LEA genes from Populus trichocarpa and renamed them as PtrLEA. The PtrLEA genes have fewer introns, and their promoters contain more cis-regulatory elements related to abiotic stress tolerance. Our results from comparative genomics indicated that the PtrLEA genes are conserved and homologous to related genes in other species, such as Eucalyptus robusta, Solanum lycopersicum and Arabidopsis. Using RNA-Seq data collected from poplar under two conditions (with and without salt treatment), we detected 24, 22 and 19 differentially expressed genes (DEGs) in roots, stems and leaves, respectively. Then we performed spatiotemporal expression analysis of the four up-regulated DEGs shared by the tissues, constructed gene co-expression-based networks, and investigated gene function annotations. Conclusion Lines of evidence indicated that the PtrLEA genes play significant roles in poplar growth and development, as well as in responses to salt stress.

scholarly journals Shoot Regeneration Is Not a Single Cell Event

Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 58
Author(s):  
Patharajan Subban ◽  
Yaarit Kutsher ◽  
Dalia Evenor ◽  
Eduard Belausov ◽  
Hanita Zemach ◽  
...  
Keyword(s):  
Gene Family ◽  
Single Cell ◽  
Shoot Regeneration ◽  
Major Gene ◽  
Molecular Genetic ◽  
Plant Biotechnology ◽  
Gene Families ◽  
Regeneration Medium ◽  
Developmental Processes ◽  
Leaf Segments

Shoot regeneration is a key tool of modern plant biotechnology. While many researchers use this process empirically, very little is known about the early molecular genetic factors and signaling events that lead to shoot regeneration. Using tobacco as a model system, we found that the inductive events required for shoot regeneration occur in the first 4–5 days following incubation on regeneration medium. Leaf segments placed on regeneration medium did not produce shoots if removed from the medium before four days indicating this time frame is crucial for the induction of shoot regeneration. Leaf segments placed on regeneration medium for longer than five days maintain the capacity to produce shoots when removed from the regeneration medium. Analysis of gene expression during the early days of incubation on regeneration medium revealed many changes occurring with no single expression pattern evident among major gene families previously implicated in developmental processes. For example, expression of Knotted gene family members increased during the induction period, whereas transcription factors from the Wuschel gene family were unaltered during shoot induction. Expression levels of genes involved in cell cycle regulation increased steadily on regeneration medium while expression of NAC genes varied. No obvious possible candidate genes or developmental processes could be identified as a target for the early events (first few days) in the induction of shoot regeneration. On the other hand, observations during the early stages of regeneration pointed out that regeneration does not occur from a single cell but a group of cells. We observed that while cell division starts just as leaf segments are placed on regeneration medium, only a group of cells could become shoot primordia. Still, these primordia are not identifiable during the first days.

scholarly journals Two Drosophila Innexins Are Expressed in Overlapping Domains and Cooperate to Form Gap-Junction Channels

2000 ◽  
Vol 11 (7) ◽  
pp. 2459-2470 ◽  
Author(s):  
Lucy A. Stebbings ◽  
Martin G. Todman ◽  
Pauline Phelan ◽  
Jonathan P. Bacon ◽  
Jane A. Davies
Keyword(s):  
Gap Junctions ◽  
Gap Junction ◽  
Ectopic Expression ◽  
In Vivo Studies ◽  
Electrophysiological Properties ◽  
Gap Junction Channels ◽  
Overlapping Domains ◽  
In Vitro Data

Members of the innexin protein family are structural components of invertebrate gap junctions and are analogous to vertebrate connexins. Here we investigate two Drosophila innexin genes,Dm-inx2 and Dm-inx3 and show that they are expressed in overlapping domains throughout embryogenesis, most notably in epidermal cells bordering each segment. We also explore the gap-junction–forming capabilities of the encoded proteins. In pairedXenopus oocytes, the injection of Dm-inx2mRNA results in the formation of voltage-sensitive channels in only ∼ 40% of cell pairs. In contrast, Dm-Inx3 never forms channels. Crucially, when both mRNAs are coexpressed, functional channels are formed reliably, and the electrophysiological properties of these channels distinguish them from those formed by Dm-Inx2 alone. We relate these in vitro data to in vivo studies. Ectopic expression ofDm-inx2 in vivo has limited effects on the viability ofDrosophila, and animals ectopically expressingDm-inx3 are unaffected. However, ectopic expression of both transcripts together severely reduces viability, presumably because of the formation of inappropriate gap junctions. We conclude that Dm-Inx2 and Dm-Inx3, which are expressed in overlapping domains during embryogenesis, can form oligomeric gap-junction channels.

Sign in / Sign up

Export Citation Format

Share Document