The Melolontha melolontha entomopoxvirus fusolin protein is a chitin-active lytic polysaccharide monooxygenase that displays extreme stability.

Spindles are intracellular crystals of the fusolin protein that enhances the oral virulence of insect poxviruses by disruption of the larval chitinous peritrophic matrix. The enigmatic fusolin protein is classified as a lytic polysaccharide monooxygenase (LPMO) by sequence and structure. Although circumstantial evidence points towards a role for fusolin in chitin degradation, no biochemical data exist to verify this claim.

ICTV Virus Taxonomy Profile: .

is a family of large, rod-shaped, enveloped entomopathogenic viruses with dsDNA genomes of 120-190 kbp. Hytrosaviruses (also known as salivary gland hypertrophy viruses) primarily replicate in the salivary glands of adult dipteran flies. Hytrosaviruses infecting the haematophagous tsetse fly and the filth-feeding housefly are assigned to two genera, and respectively.

Structural features of the salivary gland hypertrophy virus of the tsetse fly revealed by cryo-electron microscopy and tomography.

Glossina palipides salivary gland hypertrophy virus (GpSGHV) infects tsetse flies, which are vectors for African trypanosomosis. This virus represents a major challenge in insect mass rearing and has hampered the implementation of the sterile insect technique programs in the Member States of the International Atomic Energy Agency. GpSGHV virions consist of long rod-shaped particles over 9000Å in length, but little is known about their detailed structural organization.

Reprint of: Diversity of small, single-stranded DNA viruses of invertebrates and their chaotic evolutionary past.

A wide spectrum of invertebrates is susceptible to various single-stranded DNA viruses. Their relative simplicity of replication and dependence on actively dividing cells makes them highly pathogenic for many invertebrates (Hexapoda, Decapoda, etc.).

Diversity of small, single-stranded DNA viruses of invertebrates and their chaotic evolutionary past.

A wide spectrum of invertebrates is susceptible to various single-stranded DNA viruses. Their relative simplicity of replication and dependence on actively dividing cells makes them highly pathogenic for many invertebrates (Hexapoda, Decapoda, etc.).

Diversity of large DNA viruses of invertebrates.

In this review we provide an overview of the diversity of large DNA viruses known to be pathogenic for invertebrates. We present their taxonomical classification and describe the evolutionary relationships among various groups of invertebrate-infecting viruses. We also indicate the relationships of the invertebrate viruses to viruses infecting mammals or other vertebrates.

Multiple Introductions of Dengue 2 Virus Strains into Saudi Arabia from 1992 to 2014.

Introduction: Dengue is a significant arboviral infection that represents a major public health concern worldwide. The infection is endemic in most parts of South East Asia, sub-Saharan Africa, and Latin America. Among the four dengue virus (DENV) serotypes, DENV-2 has been reported to be the predominant serotype in Saudi Arabia since 1992.

Comprehensive annotation of Glossina pallidipes salivary gland hypertrophy virus from Ethiopian tsetse flies: a proteogenomics approach.

Glossina pallidipes salivary gland hypertrophy virus (GpSGHV; family Hytrosaviridae) can establish asymptomatic and symptomatic infection in its tsetse fly host. Here, we present a comprehensive annotation of the genome of an Ethiopian GpSGHV isolate (GpSGHV-Eth) compared with the reference Ugandan GpSGHV isolate (GpSGHV-Uga; GenBank accession number EF568108). GpSGHV-Eth has higher salivary gland hypertrophy syndrome prevalence than GpSGHV-Uga.

Structural basis for the enhancement of virulence by viral spindles and their in vivo crystallization.

The great benefits that chemical pesticides have brought to agriculture are partly offset by widespread environmental damage to nontarget species and threats to human health. Microbial bioinsecticides are considered safe and highly specific alternatives but generally lack potency. Spindles produced by insect poxviruses are crystals of the fusolin protein that considerably boost not only the virulence of these viruses but also, in cofeeding experiments, the insecticidal activity of unrelated pathogens.

Viruses as nanoparticles: structure versus collective dynamics.

In order to test the application of the "nanoparticle" concept to viruses in terms of low-frequency dynamics, large viruses (140-190 nm) were compared to similar-sized polymer colloids using ultra-small-angle x-ray scattering and very-low-frequency Raman or Brillouin scattering. While both viruses and polymer colloids show comparable highly defined morphologies, with comparable abilities of forming self-assembled structures, their respective abilities to confine detectable acoustic vibrations, as expected for such monodisperse systems, differed. Possible reasons for these different behaviors are discussed.

A Circo-Like Virus Isolated from Penaeus monodon Shrimps.

A virus with a circular Rep-encoding single-stranded DNA (ssDNA) (CRESS-DNA) genome (PmCV-1) was isolated from Penaeus monodon shrimps in Vietnam. The gene structure of the 1,777-nucleotide (nt) genome was similar to that of circoviruses and cycloviruses, but the nucleic acid and protein sequence identities to these viruses were very low.

A Novel Ambisense Densovirus, Acheta domesticus Mini Ambidensovirus, from Crickets.

The genome structure of Acheta domesticus mini ambidensovirus, isolated from crickets, resembled that of ambisense densoviruses from Lepidoptera but was 20% smaller. It had the highest (<25%) protein sequence identity with the nonstructural protein 1 (NS1) of Iteravirus and VP of Densovirus members (both with 25% coverage) and smaller (0.2- versus 0.

Comparative Genomic Analysis of Acheta domesticus Densovirus Isolates from Different Outbreaks in Europe, North America, and Japan.

The first densovirus from a cricket, Acheta domesticus densovirus (AdDNV) (Parvoviridae), was isolated in Europe in 1977 and has been studied previously. We compared seven additional AdDNV genomes isolated from 4 other European outbreaks, 2 major North American outbreaks, and a Japanese outbreak. Phylogenetic analysis suggested that the 2009 Japanese and North American outbreaks were not related.

Junonia coenia Densovirus (JcDNV) Genome Structure.

The sequence of Junonia coenia densovirus was the first densovirus genome sequence published, but the first published sequence contained incomplete inverted terminal repeats and ambiguous nucleotides or indels leading to an incorrect map of the open reading frames. Our sequencing of clones of the complete genome demonstrated that this virus is closely related to other viruses in the Densovirus genus.

Expression strategy of Aedes albopictus densovirus.

The transcription map of the Aedes albopictus densovirus (AalDNV) brevidensovirus was identified by Northern blotting, rapid amplification of cDNA ends (RACE) analysis, and RNase protection assays. AalDNV produced mRNAs of 3,359 (NS1), 3,345 (NS2), and 1,246 (VP) nucleotides. The two overlapping P7/7.

New Volvovirus Isolates from Acheta domesticus (Japan) and Gryllus assimilis (United States).

A novel circular single-stranded DNA (ssDNA) virus, volvovirus, from the house cricket has been described recently. Here, we report the isolation of volvoviruses from Acheta domesticus in Japan and Gryllus assimilis in the United States. These Acheta domesticus volvovirus (AdVVV) isolates have genomes of 2,517 and 2,516 nucleotides (nt) and 4 large open reading frames (ORFs).

Analysis of the transcription strategy of the Junonia coenia densovirus (JcDNV) genome.

The Junonia coenia densovirus (JcDNV) has an ambisense genome with the structural (VP) and nonstructural (NS) genes located in the 5' half on opposite strands. Northern blot analysis of Ld652 cells and Spodoptera littoralis larvae transfected with plasmid pBRJ encompassing an infectious sequence of the JcDNV genome revealed three transcripts, an unspliced 2.5 kb VP mRNA encoding capsid proteins and two NS mRNAs, one unspliced 2.

Acheta domesticus Volvovirus, a Novel Single-Stranded Circular DNA Virus of the House Cricket.

The genome of a novel virus of the house cricket consists of a 2,517-nucleotide (nt) circular single-stranded DNA (ssDNA) molecule with 4 open reading frames (ORFs). One ORF had a low identity to circovirus nucleotide sequences (NS). The unique properties of this volvovirus suggested that it belongs to a new virus family or genus.

Papilio polyxenes densovirus has an iteravirus-like genome organization.

The genome of Papilio polyxenes densovirus was cloned and sequenced and contained 5,053 nucleotides (nt), including inverted terminal repeats (ITRs) of 271 nt with terminal hairpins of 175 nt. Its DNA sequence and monosense organization with 3 open reading frames (ORFs) are typical of the genus Iteravirus in the subfamily Densovirinae of the Parvoviridae.

Iteravirus-like genome organization of a densovirus from Sibine fusca Stoll.

The complete genome of Sibine fusca densovirus was cloned and sequenced. The genome contained 5,012 nucleotides (nt), including inverted terminal repeats (ITRs) of 230 nt with terminal hairpins of 161 nt. Its DNA sequence and monosense organization with 3 open reading frames (ORFs) is typical of the genus Iteravirus in the subfamily Densovirinae of the Parvoviridae.

Improving Sterile Insect Technique (SIT) for tsetse flies through research on their symbionts and pathogens.

Tsetse flies (Diptera: Glossinidae) are the cyclical vectors of the trypanosomes, which cause human African trypanosomosis (HAT) or sleeping sickness in humans and African animal trypanosomosis (AAT) or nagana in animals. Due to the lack of effective vaccines and inexpensive drugs for HAT, and the development of resistance of the trypanosomes against the available trypanocidal drugs, vector control remains the most efficient strategy for sustainable management of these diseases. Among the control methods used for tsetse flies, Sterile Insect Technique (SIT), in the frame of area-wide integrated pest management (AW-IPM), represents an effective tactic to suppress and/or eradicate tsetse flies.

The antiviral drug valacyclovir successfully suppresses salivary gland hypertrophy virus (SGHV) in laboratory colonies of Glossina pallidipes.

Many species of tsetse flies are infected with a virus that causes salivary gland hypertrophy (SGH) symptoms associated with a reduced fecundity and fertility. A high prevalence of SGH has been correlated with the collapse of two laboratory colonies of Glossina pallidipes and colony maintenance problems in a mass rearing facility in Ethiopia. Mass-production of G.

Prevalence and genetic variation of salivary gland hypertrophy virus in wild populations of the tsetse fly Glossina pallidipes from southern and eastern Africa.

The Glossina pallidipes salivary gland hypertrophy virus (GpSGHV) is a rod-shaped, non-occluded double-stranded DNA virus that causes salivary gland hypertrophy (SGH) and reduced fecundity in the tsetse fly G. pallidipes. High GpSGHV prevalence (up to 80%) makes it impossible to mass-rear G.

Organization of the ambisense genome of the Helicoverpa armigera Densovirus.

A natural densovirus (DNV) of a serious phytophagous pest, Helicoverpa armigera, was isolated. The genome of HaDNV contained 6,039 nucleotides (nt) and included inverted terminal repeats (ITRs) of 545 nt with terminal Y-shaped hairpins of 126 nt. Its DNA sequence and ambisense organization with four typical open reading frames (ORFs) demonstrated that it belonged to the genus Densovirus in the subfamily Densovirinae of the family Parvoviridae.

Tsetse salivary gland hypertrophy virus: hope or hindrance for tsetse control?

MANY SPECIES OF TSETSE FLIES (DIPTERA: Glossinidae) are infected with a virus that causes salivary gland hypertrophy (SGH), and flies with SGH symptoms have a reduced fecundity and fertility. The prevalence of SGH in wild tsetse populations is usually very low (0.2%-5%), but higher prevalence rates (15.