Preparations of viral rna from fecal extracts showed a mixed atypical rotavirus rna profile, which was due to the presence of at least 12 subpopulations of viruses grossly differing in genotype. Mcdonald sm, matthijnssens j, mcallen jk, hine e, overton l, et al. Group a rotaviruses rva are enteric pathogens and a leading cause of severe diarrhea in human infants, as well as in young animals worldwide 1,2. In immunodeficient hosts and under certain experimental conditions, rvs undergo genome rearrangements, which. The rv genome consists of 11 segments of doublestranded rna and is enclosed within 3 concentric protein layers capsids. Isolation and characterization of a new simian rotavirus. Unusual assortment of segments in 2 rare human rotavirus. Genome rearrangements of rotaviruses 75 normal gene 10 met stop rearranged gene 10 fig. Reassortment of human rotavirus gene segments into g11. Reassortment of human rotavirus gene segments into g11 rotavirus strains. In vitro translation of genome segment 11 rnas showed that both viruses produced a polypeptide with an apparent mr of 26k. Rearrangements of rotavirus genomic segment 11 are generated. Determination of the wholegenome consensus sequence of.
Rearrangements of rotavirus genomic segment 11 are. Structural basis of glycan specificity in neonatespecific. Rotaviruses and rotavirus vaccines british medical. Because of the segmented nature of the rotavirus genome, genetic reassortment occurs at high frequency during mixed infection. It is reported that the various forms of rearrangements occurred mainly in genes coding for. However, genome rearrangements may occur, which complicate interpretation for a distinct strain. In one variant h5 the rearrangement involves the rna segment 5, while in the other variant h57 two genes, 5 and 7 are rearranged. A breakthrough in the field of rotavirus reverse genetics came in 2006, when we established the first reverse genetics system for rotaviruses, which is a partially plasmid.
The rotavirus rv genome is comprised of eleven segments of doublestranded rna dsrna and is contained within a nonenveloped, icosahedral particle. Abstract the rotavirus genome is composed of 11 gene segments of dsrna. Entirely plasmidbased reverse genetics system for rotaviruses. The solid bar represents the complete orf, and the open bar symbolizes the duplicated part of the orf of the normal gene untranslated. Grouparotaviruses have clearly been established as causing severe diarrheal disease in the young, and they may causedisease morefrequentlyin the elderly thanpreviously recognized 155. Rearrangement of parts of the rotavirus genome may be a mechanism of. Pdf genomic rearrangements in human rotavirus strain wa. Reverse genetics techniques can help clarify structurefunction relationships of viral genes andtheir protein products and alsoelucidate complex phenotypes, such as host restriction, pathogenicity, and immunogenicity. Discovery of genome rearrangements rotaviruses are the main cause of viral gastroenteritis in infants and young children and in the young of a large variety of animal species kapikian and chanock, 1990. It includes members infecting organisms from protists to humans. Dysfunction of the viral rna polymerase can lead to gene rearrangements, which most often consist of partial sequence duplication of a dsrna segment.
Rotaviruses cause approximately 600,000 deaths worldwide in children younger than five each year. The rotavirus genome is composed of 11 gene segments of dsrna. Rotavirus genes can be rearranged, due to partial nt duplications or deletions of rna segments generated by special forms of intragenic recombination. A47 wholegenome analysis of rotaviruses isolated from humans and domestic animals in uganda, 20122014 reveals possible anthroponosis and multiple rotavirus reasortment events between species. During assembly, a highly coordinated selective packaging mechanism ensures that progeny rv virions contain one of each genome segment.
Rotaviruses with genome rearrangements, isolated from a chronically infected immunodeficient child, were adapted to growth in bsc1 cells. Rotaviruses and other members of the reoviridae family undergo rearrangements of their genomes. Department of molecular virology and microbiology, and department of medicinegi, baylor college of medicine, houston, texas. Viral protein vp 2 represents the core or inner capsid, whereas vp6. Rotavirus replication, pathogenesis and vaccine development. Assortment and packaging of the segmented rotavirus genome. The prevalence and the molecular patterns of rotaviruses in calves by esther tan siew chao november 1992 supervisor.
Structural insights into the coupling of virion assembly. The rotavirus rv genome consists of 11 segments of doublestranded rna dsrna. Two porcine rotavirus strains cn86 and cc86 isolated during an epidemiological survey of diarrhoea in swine in argentina were studied because of several unique characteristics. The family reoviridae is one of the largest virus families with genomes composed of 912 doublestranded rna segments. Preparations of viral rna from fecal extracts showed a mixed atypical rotavirus rna profile, which was due to the. Health, general genomes genetic aspects rotavirus infections research rotaviruses. Summary mixed infections of secondary rhesus monkey kidney cells with human rotaviruses carrying rearranged genomes and with bovine rotavirus yielded a high percentage of reassortants.
To effectively analyze the requirements for protection to rotavirus infection, a reliable animal model that reasonably mimics infection and disease in humans is needed. Heterogeneity of genome rearrangements in rotaviruses. Analyses of some group a rotaviruses with atypical rna profiles on gels have resulted in the recognition that rear rangements within. Genome rearrangements including inversions and translocations can lead to genome plasticity, contributing to the divergence of salmonella strains. Balancing reassortment with preferred genome constellations. Complete genome analysis of a rabbit rotavirus causing. Read a major rearrangement of the vp6 gene of a strain of rotavirus provides replication advantage, veterinary microbiology on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Rotavirus structure and antigens rotavirus structure rotaviruses rvs form the genus rotavirus of the reoviridae family of viruses. Author summary rotaviruses are the most important cause of severe diarrhea in infants and young children. During assembly, a highlycoordinated selective packaging mechanism ensures that progeny rv virions contain one of each genome segment. Elucidation of the selective pressures that favor maintenance of rvs with certain sets of genes may be necessary to anticipate future vaccine needs. Genome rearrangement amino acid length outer capsid protein defective interfere.
Reassortment of human rotavirus possessing genome rearrangements with bovine rotavirus. Rotaviruses rvs are highly important pathogens that cause severe diarrhea among infants and young children worldwide. Rvs with rearranged genomes have been isolated from chronically infected. For full access to this pdf, sign in to an existing account, or purchase an annual subscription. A47 wholegenome analysis of rotaviruses isolated from. In the united states, 250,000 emergency department visits can be attributed to rotavirus. Evidence for host cell selection article pdf available in journal of general virology 68 pt 11.
No differences in any of the other virusinduced proteins made in infected ma104 cells were found on one and twodimensional gels for either. Group a, b, and c rotaviruses have been found in both humans and animals. Due to the segmented nature of their genomes, rotaviruses can exchange reassort genes during coinfections, a feature that is predicted to generate new, possibly more dangerous virus strains. Biochemical and biological comparisons between a supershort strain and its standard counterpart.
The segmented nature of the genome allows reassortment of genome segments during mixed infections, which is the major distinguishing feature of rotavirus genetics. It is well known that reovirus genomes are prone to various types of genome alterations including intragenic rearrangement and reassortment under laboratory and natural conditions. Rotavirus, the major cause of lifethreatening infantile gastroenteritis, is a member of the reoviridae1. Mechanisms that can lead to alterations in the genome include changes at the singlenucleotide level, gene loss, and genome rearrangements. Possible mechanisms of their emergence are discussed, and the significance of genome rearrangements for viral evolution is considered. This chapter discusses the genome rearrangements of rotaviruses. The rotaviruses from pfm1s stool extract were adapted to grow in ma104 and plaque purified, which revealed two distinct viruses, named yk1 and clone 311, that were distinguishable by plaque size and electropherotype figure 1a and 1b 20,21. Although the structures of rotavirus2 and other members of the reoviridae3,4 have been. Using fulllength genome sequence analysis, we investigated 2 rare g3p9 human rotavirus strains isolated from children with diarrhea. Sequence analysis of the rearranged segment 7 indicated.
This achievement opened the door to the genetic engineering of rotaviruses. Genetic analyses have contributed significantly to our understanding of the biology of the rotaviruses. In passage 96, rearrangements of rna segments 5 and 6 of the viral genome were found. However, the amount of gene reassortment occurring in nature is not known, as very few rotavirus.
Both these strains were isolated and cloned from the same faecal sample and the electrophoretic migration of 10 of their 11 genomic dsrna genomic segments in polyacrylamide gels was identical, but strain cc86 had a. As pcr was discovered, various molecular methods have been developed, mainly based on reverse transcription polymerase chain reaction rtpcr, for the rapid, specific and sensitive genotyping of rotaviruses in the laboratory. Crisprcsy4mediated editing of rotavirus doublestranded. Pdf reassortment of human rotavirus possessing genome. A new simian rotavirus, designated yk1, was isolated from a 2yearold immunodeficient pigtailed macaque with. The genotypes of 511 plaquepurified clones raised in either ma104 or bsc1 cells have been determined and the frequencies of different genotypes have been calculated.
Reassortment of human rotaviruses carrying rearranged. Rvs form a genus of the reoviridae family and contain a genome consisting of 11 double. The rotavirus rv genome comprises 11 segments of doublestranded rna dsrna and is contained within a nonenveloped, icosahedral particle. Estes department of medicine and microbiology and immunology, stanford university school of medicine, stanford, california. G9 and g12 rotaviruses combining with p8 and the 9 remaining gene segments belonging to genotype 1 10.
A group a rotavirus isolated from a lamb with diarrhea in qinhai province, china, was serially passaged in fetal calf kidney cells. We analysed biochemical, serological and biological properties of both viruses. Background rotaviruses are a major etiologic agent of gastroenteritis in infants and young children worldwide. Cisacting signals thought to mediate assortment and packaging are associated with putative panhandle structures. Genome rearrangements and evolution of rotaviruses ix. The viral genome consists of 11 doublestranded rna dsrna segments. Research progress for detection methods of rotavirus.
The rearranged genes are composed exclusively of sequences from the genes they substitute. A requirement for an effective animal model is the availability of appropriate rotavirus stocks for challenge. Results suggest multiple transmissions of genes from animal to human strains of rotaviruses. Generation of genetically stable recombinant rotaviruses. Molecular epidemiology and genetic evolution of the whole.
Genome rearrangements in other genera of reoviridae x. Rotaviruses and rotavirus vaccines oxford academic journals. Veterinary medicine and animal science a study was conducted to determine the prevalence of rota virus in calves in malaysia. A g3p porcine group a rotavirus emerging in china is a. Rotavirus protein involved in genome replication and. Two rotavirus variants containing genomic rearrangements were isolated from human rotavirus strain wa. Genome rearrangements of rotaviruses sciencedirect. The understanding of the molecular mechanisms underlying rv replication and pathogenesis has been hampered by the lack of an entirely plasmidbased reverse genetics system. Genetic engineering of rotaviruses by reverse genetics komoto. Genomic rearrangements in human rotavirus strain wa. The rotavirus genome consists of 11 segments of doublestranded rna encoding six structural viral proteins vp1 to vp4, vp6, and vp7 and six nonstructural viral proteins nsp1 to nsp6 3,4. Preparations of viral rna from fecal extracts showed a. Production of viral progeny requires the coordination of a series of events. Rotaviruses with rearrangements in 3 genes were found to package approximately 1800 additional bp of rna, i.