scholarly journals A Novel Virus of Flaviviridae Associated with Sexual Precocity in Macrobrachium rosenbergii

mSystems ◽  
2021 ◽  
Author(s):  
Xuan Dong ◽  
Guohao Wang ◽  
Tao Hu ◽  
Juan Li ◽  
Chen Li ◽  
...  
Keyword(s):  
Macrobrachium Rosenbergii ◽  
Economic Losses ◽  
Sexual Precocity ◽  
Novel Virus

The iron prawn syndrome (IPS), also described as sexual precocity, results in the reduced size of farmed prawns at harvest and significant economic losses. IPS has been frequently reported in populations of farmed Macrobrachium rosenbergii since 2010, but the cause was heretofore unknown.

scholarly journals Sex Differences in Spatial Activity and Anxiety Levels in the COVID-19 Pandemic from Evolutionary Perspective

2021 ◽  
Vol 13 (3) ◽  
pp. 1110
Author(s):  
Olga Semenova ◽  
Julia Apalkova ◽  
Marina Butovskaya
Keyword(s):  
Environmental Risks ◽  
Economic Losses ◽  
General Level ◽  
The Novel ◽  
Health Attitudes ◽  
Spatial Activity ◽  
Sexual Specialization ◽  
The Face ◽  
Novel Virus ◽  
Virus Spreading

Despite the enforced lockdown regime in late March 2020 in Russia, the phenomenon of the continued virus spreading highlighted the importance of studies investigating the range of biosocial attributes and spectrum of individual motivations underlying the permanent presence of the substantial level of spatial activity. For this matter, we conducted a set of surveys between March and June 2020 (N = 492). We found that an individual’s health attitude is the most consistent factor explaining mobility differences. However, our data suggested that wariness largely determines adequate health attitudes; hence, a higher level of wariness indirectly reduced individual mobility. Comparative analysis revealed the critical biosocial differences between the two sexes, potentially rooted in the human evolutionary past. Females were predisposed to express more wariness in the face of new environmental risks; therefore, they minimize their mobility and outdoor contacts. In contrast to them, the general level of spatial activity reported by males was significantly higher. Wariness in the males’ sample was less associated with the novel virus threat, but to a great extent, it was predicted by the potential economic losses variable. These findings correspond to the evolutionary predictions of sexual specialization and the division of family roles.

scholarly journals A Novel RNA Virus, Macrobrachium rosenbergii Golda Virus (MrGV), Linked to Mass Mortalities of the Larval Giant Freshwater Prawn in Bangladesh

Viruses ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1120
Author(s):  
Chantelle Hooper ◽  
Partho P. Debnath ◽  
Sukumar Biswas ◽  
Ronny van Aerle ◽  
Kelly S. Bateman ◽  
...  
Keyword(s):  
Virus Assembly ◽  
Rna Virus ◽  
Macrobrachium Rosenbergii ◽  
Freshwater Prawn ◽  
The Novel ◽  
Protein Motifs ◽  
Giant Freshwater Prawn ◽  
Yellow Head Virus ◽  
Novel Virus ◽  
Mass Mortalities

Mass mortalities of the larval stage of the giant freshwater prawn, Macrobrachium rosenbergii, have been occurring in Bangladesh since 2011. Mortalities can reach 100% and have resulted in an 80% decline in the number of hatcheries actively producing M. rosenbergii. To investigate a causative agent for the mortalities, a disease challenge was carried out using infected material from a hatchery experiencing mortalities. Moribund larvae from the challenge were prepared for metatranscriptomic sequencing. De novo virus assembly revealed a 29 kb single-stranded positive-sense RNA virus with similarities in key protein motif sequences to yellow head virus (YHV), an RNA virus that causes mass mortalities in marine shrimp aquaculture, and other viruses in the Nidovirales order. Primers were designed against the novel virus and used to screen cDNA from larvae sampled from hatcheries in the South of Bangladesh from two consecutive years. Larvae from all hatcheries screened from both years were positive by PCR for the novel virus, including larvae from a hatchery that at the point of sampling appeared healthy, but later experienced mortalities. These screens suggest that the virus is widespread in M. rosenbergii hatchery culture in southern Bangladesh, and that early detection of the virus can be achieved by PCR. The hypothesised protein motifs of Macrobrachium rosenbergii golda virus (MrGV) suggest that it is likely to be a new species within the Nidovirales order. Biosecurity measures should be taken in order to mitigate global spread through the movement of post-larvae within and between countries, which has previously been linked to other virus outbreaks in crustacean aquaculture.

scholarly journals Cryo-electron Microscopy Structures of Novel Viruses from Mud Crab Scylla paramamosain with Multiple Infections

2019 ◽  
Vol 93 (7) ◽  
Author(s):  
Yuanzhu Gao ◽  
Shanshan Liu ◽  
Jiamiao Huang ◽  
Qianqian Wang ◽  
Kunpeng Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
3D Structure ◽  
Structural Features ◽  
Economic Losses ◽  
Scylla Paramamosain ◽  
Multiple Infections ◽  
Mud Crab ◽  
Cryo Electron Microscopy ◽  
Novel Virus ◽  
Icosahedral Capsid

ABSTRACT Viruses associated with sleeping disease (SD) in crabs cause great economic losses to aquaculture, and no effective measures are available for their prevention. In this study, to help develop novel antiviral strategies, single-particle cryo-electron microscopy was applied to investigate viruses associated with SD. The results not only revealed the structure of mud crab dicistrovirus (MCDV) but also identified a novel mud crab tombus-like virus (MCTV) not previously detected using molecular biology methods. The structure of MCDV at a 3.5-Å resolution reveals three major capsid proteins (VP1 to VP3) organized into a pseudo-T=3 icosahedral capsid, and affirms the existence of VP4. Unusually, MCDV VP3 contains a long C-terminal region and forms a novel protrusion that has not been observed in other dicistrovirus. Our results also reveal that MCDV can release its genome via conformation changes of the protrusions when viral mixtures are heated. The structure of MCTV at a 3.3-Å resolution reveals a T= 3 icosahedral capsid with common features of both tombusviruses and nodaviruses. Furthermore, MCTV has a novel hydrophobic tunnel beneath the 5-fold vertex and 30 dimeric protrusions composed of the P-domains of the capsid protein at the 2-fold axes that are exposed on the virion surface. The structural features of MCTV are consistent with a novel type of virus. IMPORTANCE Pathogen identification is vital for unknown infectious outbreaks, especially for dual or multiple infections. Sleeping disease (SD) in crabs causes great economic losses to aquaculture worldwide. Here we report the discovery and identification of a novel virus in mud crabs with multiple infections that was not previously detected by molecular, immune, or traditional electron microscopy (EM) methods. High-resolution structures of pathogenic viruses are essential for a molecular understanding and developing new disease prevention methods. The three-dimensional (3D) structure of the mud crab tombus-like virus (MCTV) and mud crab dicistrovirus (MCDV) determined in this study could assist the development of antiviral inhibitors. The identification of a novel virus in multiple infections previously missed using other methods demonstrates the usefulness of this strategy for investigating multiple infectious outbreaks, even in humans and other animals.

scholarly journals Structure of the Macrobrachium rosenbergii Nodavirus: A new genus within the Nodaviridae?

2018 ◽  
Author(s):  
Kok Lian Ho ◽  
Mads Gabrielsen ◽  
Poay Ling Beh ◽  
Chare Li Kueh ◽  
Qiu Xian Thong ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Macrobrachium Rosenbergii ◽  
Atomic Resolution ◽  
Freshwater Prawn ◽  
Economic Losses ◽  
Capsid Shell ◽  
Long Range Interactions ◽  
Virion Structure ◽  
Resolution Model ◽  
Resolution Structure

AbstractMacrobrachium rosenbergii nodavirus (MrNV) is a pathogen of freshwater prawns that poses a threat to food-security and causes significant economic losses in the aquaculture industries of many developing nations. A detailed understanding of the MrNV virion structure will inform the development of strategies to control outbreaks. The MrNV capsid has also been engineered to display heterologous antigens, thus knowledge of its atomic resolution structure will benefit efforts to develop tools based on this platform. Here we present an atomic-resolution model of the MrNV capsid protein, calculated by cryogenic electron microscopy (cryoEM) of MrNV virus-like particles (VLPs) produced in insect cells, and three-dimensional image reconstruction at 3.3 Å resolution. CryoEM of MrNV virions purified from infected freshwater prawn post-larvae yielded a 6.6 Å resolution structure confirming the biological relevance of the VLP structure.Our data revealed that unlike other known nodaviruses structures, which have been shown to assemble capsids having trimeric spikes, MrNV assembles a T=3 capsid with dimeric spikes. We also found a number of surprising similarities between the MrNV capsid structure and that of the Tombusviridae. 1. An extensive network of N-terminal arms lines the capsid interior forming long-range interactions to lace together asymmetric units. 2. The capsid shell is stabilised by three pairs of Ca2+ ions in each asymmetric unit. 3. The protruding spike domain exhibits a very similar fold to that seen in the spikes of the tombusviruses. These structural similarities raise questions concerning the correct taxonomic classification of MrNV.

scholarly journals A novel RNA virus, Macrobrachium rosenbergii Golda virus (MrGV), linked to mass mortalities of the larval giant freshwater prawn in Bangladesh

2020 ◽  
Author(s):  
Chantelle Hooper ◽  
Partho P. Debnath ◽  
Sukumar Biswas ◽  
Ronny van Aerle ◽  
Kelly S. Bateman ◽  
...  
Keyword(s):  
Virus Assembly ◽  
Rna Virus ◽  
Macrobrachium Rosenbergii ◽  
Freshwater Prawn ◽  
The Novel ◽  
Protein Motifs ◽  
Giant Freshwater Prawn ◽  
Yellow Head Virus ◽  
Novel Virus ◽  
Mass Mortalities

1AbstractMass mortalities of the larval stage of the giant freshwater prawn, Macrobrachium rosenbergii, have been occurring in Bangladesh since 2011. Mortalities can reach 100% and have resulted in an 80% decline in the number of hatcheries actively producing M. rosenbergii. To investigate a causative agent for the mortalities, a disease challenge was carried out using infected material from a hatchery experiencing mortalities. Moribund larvae from the challenge were prepared for metatranscriptomic sequencing. De novo virus assembly revealed a 29 kb single-stranded positive-sense RNA virus with similarities in key protein motif sequences to yellow head virus (YHV), an RNA virus that causes mass mortalities in marine shrimp aquaculture, and other viruses in the Nidovirales order. Primers were designed against the novel virus and used to screen cDNA from larvae sampled from hatcheries in the South of Bangladesh from two consecutive years. Larvae from all hatcheries screened from both years were positive by PCR for the novel virus, including larvae from a hatchery that at the point of sampling appeared healthy, but later experienced mortalities. These screens suggest that the virus is widespread in M. rosenbergii hatchery culture in southern Bangladesh, and that early detection of the virus can be achieved by PCR. The hypothesised protein motifs of MrGV suggest that it is likely to be a new species within the Nidovirales order. Biosecurity measures should be taken in order to mitigate global spread through the movement of post-larvae within and between countries, which has previously been linked to other virus outbreaks in crustacean aquaculture.

scholarly journals Reproductive and growth performances in female giant freshwater prawn following inhibition of gonadal maturation using dopamine and medroxyprogesterone hormone

2020 ◽  
Vol 19 (1) ◽  
pp. 10-18
Author(s):  
Megawati Wijaya ◽  
Agus Oman Sudrajat ◽  
Imron
Keyword(s):  
Growth Rate ◽  
Gonad Development ◽  
Macrobrachium Rosenbergii ◽  
Somatic Growth ◽  
Freshwater Prawn ◽  
Economic Losses ◽  
Mature Stage ◽  
Gonadal Maturation ◽  
Giant Freshwater Prawn ◽  
Gonadal Maturity

ABSTRACT One of the main problem in giant river prawn (GFP) culture is early gonadal maturation in female resulting a reduced growth performance. This problem cause economic losses. When GFP at gonadal maturation, somatic growth will be inhibited because energy is used for reproduction. A factorial experimental design using two factors, namely dopamine and medroxyprogesterone, with each factor consist of three levels was applied. Three dopamine levels were 0, 10-5 mol/shrimp, and 10-10 mol/shrimp, while the medroxyprogesterone levels were 0, 75 mg/1.5 mL/bodyweight, and 150 mg/3 mL/bodyweight with a density 15 individual/tank. The utilization of dopamine and medroxyprogesterone in GFP (initial bodyweight : 11.27 ± 0.97 g) through injection at the third periopod was done three times at week 0, 2nd, and 4th with two weeks interval. The results showed that hormone inhibitor treatments affected both growth and reproductive performances in female GFP. The treated individuals showed a lower gonadal maturity indicator values and faster growth rate than control. Gonadal maturity, as shown by gonad histology, in all treatments were lower (previtelogenic and vitellogenic stages) than that in control which is in mature stage. Estradiol concentration premix dopamine 10-10 mol/shrimp and medroxyprogesterone 150 mg/3 mL/bodyweight treatments are lower than control. In conclusion, dopamine and medroxyprogesterone administration could suppres GSI and gonad development, and also increase growth rate. Keywords: Macrobrachium rosenbergii, dopamine, medroxyprogesterone, gonad development, growth.

scholarly journals Cryo-Electron Microscopy Structure of the Macrobrachium rosenbergii Nodavirus Capsid at 7 Angstroms Resolution

2017 ◽  
Author(s):  
Kok Lian Ho ◽  
Chare Li Kueh ◽  
Poay Ling Beh ◽  
Wen Siang Tan ◽  
David Bhella
Keyword(s):  
Electron Microscopy ◽  
Developing Countries ◽  
Food Security ◽  
Outer Surface ◽  
Macrobrachium Rosenbergii ◽  
Freshwater Prawn ◽  
Economic Losses ◽  
Viral Capsid ◽  
Giant Freshwater Prawn ◽  
Shrimp Farms

AbstractWhite tail disease in the giant freshwater prawn Macrobrachium rosenbergii causes significant economic losses in shrimp farms and hatcheries and poses a threat to food-security in many developing countries. Outbreaks of Macrobrachium rosenbergii nodavirus (MrNV), the causative agent of white tail disease (WTD) are associated with up to 100% mortality rates. Recombinant expression of the capsid protein of MrNV in insect cells leads to the production of VLPs closely resembling the native virus. We have investigated the structure of MrNV VLPs by cryogenic electron microscopy, determining a structure of the viral capsid at 7 angstroms resolution. Our data show that MrNV VLPs package nucleic acids in a manner reminiscent of other known nodavirus structures. The structure of the capsid however shows striking differences from insect and fish infecting nodaviruses, which have been shown to assemble trimer-clustered T=3 icosahedral virus particles. MrNV particles have pronounced dimeric blade-shaped spikes extending up to 6 nm from the outer surface of the capsid shell. Our structural analysis supports the assertion that MrNV along with the related virus of marine shrimp Penaeus vannamei nodavirus (PvNV) may represent a new genus of the Nodaviridae.Author summaryMacrobrachium rosenbergii nodavirus (MrNV) is the causative agent of white tail disease (WTD) which leads to 100% mortality in shrimp-farms growing giant freshwater prawn (M. rosenbergii). MrNV is therefore a significant threat to food security and causes severe economic losses in developing countries such as Malaysia, Indonesia, Pakistan, Thailand and India. Here we have used electron microscopy to study the three-dimensional structure of MrNV, revealing that the viral capsid – the protein shell that encloses the viral genome, protecting it and transporting it from one host to the next – is differently organised to capsids produced by other viruses in the nodavirus family. The virus was found to have large blade-like spikes on its outer surface that are likely important in the early stages of infection, when the virus attaches to and enters a host cell.

Is SARS CoV-2 a new Frankenstein monster virus? (Preprint)

2020 ◽  
Author(s):  
Mohammed El-Magd
Keyword(s):  
Immune Response ◽  
Mortality Rate ◽  
Current Knowledge ◽  
Virus Disease ◽  
The Other ◽  
Economic Losses ◽  
Host Cell Factors ◽  
Novel Virus ◽  
Transmission Ability

BACKGROUND Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel virus of beta coronavirus genus originated in Wuhan, China in December 2019, resulted in the pandemic spread of Corona Virus Disease 2019 (COVID-19) worldwide. This genus also contains SARS-CoV (originated in China 2002-2003) and MERS-CoV (found in Saudi Arabia 2012). The nucleotide sequences of SARS-CoV-2 is closer to SARS-CoV (with approximately 80% identity) than to MERS-CoV. Despite these similarities, SARS-CoV-2 has two main features over the other coronaviruses. The first is the high contagious rate and the second is the immune response evasion. The higher transmission ability makes this virus quickly spread worldwide with a high mortality rate and more economic losses. This review will provide an overview of the current knowledge on the role of some viral and host cell factors in higher transmission and contagious spread of SARS-CoV-2.

scholarly journals Characterization of a Novel Virus Causing a Lethal Disease in Carp and Koi

2006 ◽  
Vol 70 (1) ◽  
pp. 147-156 ◽  
Author(s):  
Maya Ilouze ◽  
Arnon Dishon ◽  
Moshe Kotler
Keyword(s):  
Immune Response ◽  
Fish Farming ◽  
Economic Losses ◽  
Molecular Characteristics ◽  
Economic Aspects ◽  
Isolation And Identification ◽  
Dna Viruses ◽  
Novel Virus ◽  
Farming Industry

SUMMARY Since 1998 a lethal disease of carp and ornamental koi (Cyprinus carpio) has afflicted fisheries in North America, Europe, and Asia, causing severe economic losses to the fish farming industry. This review summarizes the isolation and identification of the disease-causing agent and describes the currently known molecular characteristics of this newly isolated virus, distinguishing it from other known large DNA viruses. In addition, we summarize the clinical and histopathological manifestations of the disease. Providing information on the immune response to this virus and evaluating the available means of diagnosis and protection should help to reduce the damage induced by this disease. This review does not discuss the economic aspects of the disease or the debate on whether the disease should be registered; both of these issues were recently reviewed in detail (O. L. M. Haenen, K. Way, S. M. Bergmann, and E. Ariel, Bull. Eur. Assoc. Fish Pathol. 24:293-307, 2004; D. Pokorova, T. Vesely, V. Piackova, S. Reschova, and J. Hulova, Vet. Med. Czech. 50:139-147, 2005).

The Microscopy of Compatibility and Incompatibility in Ulmus

1985 ◽  
Vol 43 ◽  
pp. 504-505
Author(s):  
B. L. Redmond ◽  
Christopher F. Bob
Keyword(s):  
Dutch Elm Disease ◽  
Economic Losses ◽  
Hybrid Progeny ◽  
Ulmus Pumila ◽  
Ulmus Americana ◽  
American Elm ◽  
Asian Species ◽  
Ulmus Parvifolia ◽  
Initial Appearance ◽  
Chinese Elm

The American Elm (Ulmus americana L.) has been plagued by Dutch Elm Disease (DED), a lethal disease caused by the fungus Ceratocystis ulmi (Buisman) c. Moreau. Since its initial appearance in North America around 1930, DED has wrought inexorable devastation on the American elm population, triggering both environmental and economic losses. In response to the havoc caused by the disease, many attempts have been made to hybridize U. americana with a few ornamentally less desirable, though highly DED resistant, Asian species (mainly the Siberian elm, Ulmus pumila L., and the Chinese elm Ulmus parvifolia Jacq.). The goal is to develop, through breeding efforts, hybrid progeny that display the ornamentally desirable characteristics of U. americana with the disease resistance of the Asian species. Unfortunately, however, all attempts to hybridize U. americana have been prevented by incompatibility. Only through a firm understanding of both compatibility and incompatibility will it be possible to circumvent the incompatibility and hence achieve hybridization.

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