scholarly journals Genomic RNA sequence of feline coronavirus strain FCoV C1Je

2007 ◽  
Vol 9 (3) ◽  
pp. 202-213 ◽  
Author(s):  
Charlotte Dye ◽  
Stuart G. Siddell

This paper reports the first genomic RNA sequence of a field strain feline coronavirus (FCoV). Viral RNA was isolated at post mortem from the jejunum and liver of a cat with feline infectious peritonitis (FIP). A consensus sequence of the jejunum-derived genomic RNA (FCoV C1Je) was determined from overlapping cDNA fragments produced by reverse transcriptase polymerase chain reaction (RT-PCR) amplification. RT-PCR products were sequenced by a reiterative sequencing strategy and the genomic RNA termini were determined using a rapid amplification of cDNA ends PCR strategy. The FCoV C1Je genome was found to be 29,255 nucleotides in length, excluding the poly(A) tail. Comparison of the FCoV C1Je genomic RNA sequence with that of the laboratory strain FCoV FIP virus (FIPV) 79-1146 showed that both viruses have a similar genome organisation and predictions made for the open reading frames and cis-acting elements of the FIPV 79-1146 genome hold true for FCoV C1Je. In addition, the sequence of the 3′-proximal third of the liver derived genomic RNA (FCoV C1Li), which encompasses the structural and accessory protein genes of the virus, was also determined. Comparisons of the enteric (jejunum) and non-enteric (liver) derived viral RNA sequences revealed 100% nucleotide identity, a finding that questions the well accepted ‘internal mutation theory’ of FIPV pathogenicity.

2005 ◽  
Vol 86 (8) ◽  
pp. 2249-2253 ◽  
Author(s):  
Charlotte Dye ◽  
Stuart G. Siddell

A consensus sequence of the Feline coronavirus (FCoV) (strain FIPV WSU-79/1146) genome was determined from overlapping cDNA fragments produced by RT-PCR amplification of viral RNA. The genome was found to be 29 125 nt in length, excluding the poly(A) tail. Analysis of the sequence identified conserved open reading frames and revealed an overall genome organization similar to that of other coronaviruses. The genomic RNA was analysed for putative cis-acting elements and the pattern of subgenomic mRNA synthesis was analysed by Northern blotting. Comparative sequence analysis of the predicted FCoV proteins identified 16 replicase proteins (nsp1–nsp16) and four structural proteins (spike, membrane, envelope and nucleocapsid). Two mRNAs encoding putative accessory proteins were also detected. Phylogenetic analyses confirmed that FIPV WSU-79/1146 belongs to the coronavirus subgroup G1-1. These results confirm and extend previous findings from partial sequence analysis of FCoV genomes.


2001 ◽  
Vol 75 (17) ◽  
pp. 8298-8305 ◽  
Author(s):  
K. R. Bonneau ◽  
B. A. Mullens ◽  
N. J. MacLachlan

ABSTRACT Bluetongue virus (BTV) is the cause of an insect-transmitted virus infection of ruminants that occurs throughout much of the world. Individual gene segments differ between field strains of BTV; thus, we hypothesized that key viral genes undergo genetic drift during alternating passage of BTV in its ruminant and insect hosts. To test this hypothesis, variation in the consensus sequence and quasispecies heterogeneity of the VP2 and NS3/NS3A genes of a plaque-purified strain of BTV serotype 10 was determined during alternating infection of vector Culicoides sonorensis and a sheep and calf. Consensus sequences were determined after reverse transcriptase-nested PCR amplification of viral RNA directly from ruminant blood and homogenized insects, and quasispecies heterogeneity was determined by the sequencing of clones derived from directly amplified viral RNA. Comparison of these sequences to those of the original BTV inoculum used to initiate the cycle of BTV infection demonstrated, for the first time, that individual BTV gene segments evolve independently of one another by genetic drift in a host-specific fashion, generating quasispecies populations in both ruminant and insect hosts. Furthermore, a unique viral variant was randomly ingested by C. sonorensis insects that fed on a sheep with low-titer viremia, thereby fixing a novel genotype by founder effect. Thus, we conclude that genetic drift and founder effect contribute to diversification of individual gene segments of field strains of BTV.


2020 ◽  
Author(s):  
Nidhi Kumari ◽  
Vivek Sharma ◽  
Sneha Choudhary ◽  
P.N. Sharma

AbstractThe PCR amplification of majority of the ssRNA of both genomic and non-genomic mRNA is accomplished by RT-PCR. The mRNA is subjected to cDNA synthesis using reverse transcriptase and either Oligo(dT)18, or random or gene specific reverse primers based priming strategies. The choice of primer largely depends on the nature of 3 prime terminus of mRNA and length of cDNA synthesized. In general, oligo(dT)18 is the preferred choice for mRNAs having poly(A) tail at 3 prime terminus. In general, tobamoviruses lack any poly(A) tail at their 3 prime untranslated region (UTR) which forms a tRNA like structure and upstream pseudoknot domain except tow viruses viz., Hibiscus latent Fort Pierce virus (HLFPV) and Hibiscus latent Singapore virus (HLSV) which accommodate internal poly(A) sequences of 46 and 87 nucleotides long, respectively in their 3 prime UTR. However, determination of full nucleotide sequence of Pepper mild mottle virus (PMMoV) using an oligo(dT)18 primed cDNA as template indicated the libertinism of oligo(dT)18 in priming cDNA synthesis of RNA template which are known to lack poly(A) tail. at the end or internally at its 3 prime end. Moreover, coat protein (CP) gene of PMMoV and bean common mosaic virus (BCMV) (Potyvirus with a poly(A) tract at its 3 prime end) was amplified using cDNA primed with random primer as well as oligo(dT)18 was successfully amplified but with significant variation in the intensity of the amplification band in case of PMMoV but not in BCMV. This clearly indicated the presence of PMMoV mRNA with polyadenylated 3 prime tail in total RNA isolated from PMMoV infected capsicum leaves with abundance of non-polyadenylated PMMoV genomic RNA (gRNA). Hence, we hypothesize that the generation of polyadenylated RNA population during the infection cycle of PMMoV in pepper may be possible reason for libertinism of oligo(dT)18 in priming cDNA synthesis of RNA template isolated from PMMoV infected leaves followed by amplification of entire PMMoV genome through RT-PCR. This is first study indicating the presence of polyadenylated or polyadenylated rich regions in PMMoV gRNA acquired during the infection cycle in pepper.


Plant Disease ◽  
2002 ◽  
Vol 86 (12) ◽  
pp. 1402-1402 ◽  
Author(s):  
Juliana Freitas-Astúa ◽  
Lisela Moreira ◽  
Carmen Rivera ◽  
Carlos M. Rodríguez ◽  
Elliot W. Kitajima

Orchid fleck virus (OFV), a tentative member of the family Rhabdoviridae, infects orchids in several countries. The virus is vectored worldwide by the mite Brevipalpus californicus (Banks) (Acari: Tenuipalpidae). Eleven plants of Oncidium spp. and one plant each of the genera Cymbidium and Maxillaria exhibiting numerous yellow flecks and necrotic ringspot lesions on leaves were collected in two private orchid collections in Costa Rica. Presence of OFV was assessed by plate-trapped antigen enzyme-linked immunosorbent assay (PTA-ELISA) using an antiserum developed against an OFV isolate in Japan (2), analyses of ultrathin sections of the host cell with transmission electron microscopy (TEM), and reverse transcription-polymerase chain reaction (RT-PCR) amplification using specific primers for the viral nucleocapsid gene (1). Eight of eleven Oncidium samples, and both Cymbidium and Maxillaria samples tested positive for OFV with PTA-ELISA having A405 values ranging from 3.9 to 14.6 times higher than negative controls. Thin sections from individual samples of Cymbidium, Oncidium, and Maxillaria revealed electron-lucent intranuclear viroplasm and short, rodlike particles (40 to 50 × 100 nm) in the nucleus or cytoplasm typical of OFV-infected cells. RT-PCR amplifications from one sample of each genera resulted in PCR-product bands of approximately 800 bp. The Cymbidium RT-PCR product was cloned into a pGEM-T-Easy expression vector and sequenced using an ABI 3700 sequencer. The 619-bp nucleocapsid gene consensus sequence had 98% homology with the OFV isolate 0023 identified in Germany (GenBank Accession No. AF343870) (1). However, it had only approximately 85% nucleocapsid gene homology with other OFV isolates available through GenBank, including those from countries geographically closer to Costa Rica, such as Brazil (1). To our knowledge, this is the first report of OFV infecting orchids in Costa Rica. References: (1) A. L. Blanchfield et al. J. Phytopathol. 149:713, 2001. (2) H. Kondo et al. Bull. Res. Inst. Bioresour. Okayama Univ. 4:149, 1996.


2020 ◽  
Vol 6 (2) ◽  
pp. 205511692094147
Author(s):  
Christopher Hoey ◽  
George Nye ◽  
Angela Fadda ◽  
Janet Bradshaw ◽  
Emi N Barker

Case summary A 7-month-old Siberian cat was presented for investigation of acute onset multifocal neurological deficits. Neurological examination documented dull mental status and an ambulatory left hemiparesis. Serum biochemistry documented marked hyperglobulinaemia. MRI of the brain identified marked leptomeningeal contrast enhancement extending along the brainstem caudally to involve the cranial cervical spinal cord. MRI of the cervical spine further identified a subarachnoid diverticulum that extended from the level of the obex to the C2–C3 vertebrae. Cerebrospinal fluid quantitative RT-PCR was positive for the presence of feline coronavirus. Histopathology revealed pyogranulomatous meningitis and choroid plexitis, uveitis and nephritis. Relevance and novel information This article describes the first reported case of a subarachnoid diverticulum associated with feline infectious peritonitis.


Author(s):  
Tae Goo Kang ◽  
Hong Miao Ji ◽  
Siow Pin Melvin Tan ◽  
Guang Kai Ignatius Tay ◽  
Ming Yi Daniel Ang ◽  
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Keyword(s):  

1999 ◽  
Vol 354 (1383) ◽  
pp. 583-586 ◽  
Author(s):  
H. Fraenkel-Conrat ◽  
B. Singer

This paper is a historical overview of the work done on the tobacco mosaic virus. The primary finding was that a virus is capable of reassembling itself from its component protein and RNA, and that only the RNA carries the genomic capability of the virus. This was followed by detailed studies of the chemical and biological properties of viral RNA.


2016 ◽  
Vol 19 (3) ◽  
pp. 655-657 ◽  
Author(s):  
J. Kęsik-Maliszewska ◽  
M. Larska

Abstract The detection of Schmallenberg virus (SBV) in the breeding bull semen raised the question of the possibility of venereal transmission of SBV which could result in cost-intensive restrictions in the trade of bovine semen. In order to evaluate the presence of SBV RNA in bovine semen, 131 bull semen samples from four locations in Poland collected between 2013 and 2015 were analysed by RT-PCR for viral RNA. SBV RNA was detected in 5.3% of the samples. The study has revealed that application of an appropriate RNA extraction method is crucial to detect virus excretion via semen.


2017 ◽  
Vol 199 (8) ◽  
Author(s):  
Emily A. Sansevere ◽  
Xiao Luo ◽  
Joo Youn Park ◽  
Sunghyun Yoon ◽  
Keun Seok Seo ◽  
...  

ABSTRACT ICE6013 represents one of two families of integrative conjugative elements (ICEs) identified in the pan-genome of the human and animal pathogen Staphylococcus aureus. Here we investigated the excision and conjugation functions of ICE6013 and further characterized the diversity of this element. ICE6013 excision was not significantly affected by growth, temperature, pH, or UV exposure and did not depend on recA. The IS30-like DDE transposase (Tpase; encoded by orf1 and orf2) of ICE6013 must be uninterrupted for excision to occur, whereas disrupting three of the other open reading frames (ORFs) on the element significantly affects the level of excision. We demonstrate that ICE6013 conjugatively transfers to different S. aureus backgrounds at frequencies approaching that of the conjugative plasmid pGO1. We found that excision is required for conjugation, that not all S. aureus backgrounds are successful recipients, and that transconjugants acquire the ability to transfer ICE6013. Sequencing of chromosomal integration sites in serially passaged transconjugants revealed a significant integration site preference for a 15-bp AT-rich palindromic consensus sequence, which surrounds the 3-bp target site that is duplicated upon integration. A sequence analysis of ICE6013 from different host strains of S. aureus and from eight other species of staphylococci identified seven divergent subfamilies of ICE6013 that include sequences previously classified as a transposon, a plasmid, and various ICEs. In summary, these results indicate that the IS30-like Tpase functions as the ICE6013 recombinase and that ICE6013 represents a diverse family of mobile genetic elements that mediate conjugation in staphylococci. IMPORTANCE Integrative conjugative elements (ICEs) encode the abilities to integrate into and excise from bacterial chromosomes and plasmids and mediate conjugation between bacteria. As agents of horizontal gene transfer, ICEs may affect bacterial evolution. ICE6013 represents one of two known families of ICEs in the pathogen Staphylococcus aureus, but its core functions of excision and conjugation are not well studied. Here, we show that ICE6013 depends on its IS30-like DDE transposase for excision, which is unique among ICEs, and we demonstrate the conjugative transfer and integration site preference of ICE6013. A sequence analysis revealed that ICE6013 has diverged into seven subfamilies that are dispersed among staphylococci.


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