Genetic diversity of a natural population of Cucurbit yellow stunting disorder virus

An analysis of nucleotide sequences in five coding and one non-coding genomic regions of 35 Cucurbit yellow stunting disorder virus (CYSDV) isolates collected on a local scale over an 8 year period is reported here. In total, 2277 nt were sequenced for each isolate, representing about 13 % of the complete virus genome. Mean nucleotide diversity for the whole population in synonymous positions in the coding regions was 0·00068, whilst in the 5′ untranslated region (5′ UTR) of genomic RNA2, it was 0·00074; both of these values are very small, compared with estimates of nucleotide diversity for populations of other plant viruses. Nucleotide diversity was also determined independently for each of the ORFs and for the 5′ UTR of RNA2; the data showed that variability is not distributed evenly among the different regions of the viral genome, with the coat protein gene showing more diversity than the other four coding regions that were analysed. However, the low variability found precluded any inference of selection differences among gene regions. On the other hand, no evidence of selection associated with host adaptation was found. In contrast, at least a single amino acid change in the coat protein appears to have been selected with time.

Download Full-text

Coat protein gene sequences of two cucumber mosaic virus strains reveal a single amino acid change correlating with chlorosis induction

Journal of General Virology ◽

10.1099/0022-1317-72-10-2587 ◽

1991 ◽

Vol 72 (10) ◽

pp. 2587-2589 ◽

Cited By ~ 23

Author(s):

M. Shintaku

Keyword(s):

Amino Acid ◽

Coat Protein ◽

Cucumber Mosaic Virus ◽

Mosaic Virus ◽

Coat Protein Gene ◽

Amino Acid Change ◽

Protein Gene ◽

Single Amino Acid ◽

Single Amino Acid Change ◽

Virus Strains

Download Full-text

A single amino acid change in the coat protein of Maize streak virus abolishes systemic infection, but not interaction with viral DNA or movement protein

Molecular Plant Pathology ◽

10.1046/j.1464-6722.2001.00068.x ◽

2001 ◽

Vol 2 (4) ◽

pp. 223-228 ◽

Cited By ~ 16

Author(s):

Huanting Liu ◽

Andrew ◽

P. Lucy ◽

Jeffrey W. Davies ◽

Margaret I. Boulton

Keyword(s):

Amino Acid ◽

Coat Protein ◽

Amino Acid Change ◽

Movement Protein ◽

Systemic Infection ◽

Maize Streak Virus ◽

Single Amino Acid ◽

Streak Virus ◽

Viral Dna ◽

Single Amino Acid Change

Download Full-text

Mutations in oxyR Resulting in Peroxide Resistance in Xanthomonas campestris

Journal of Bacteriology ◽

10.1128/jb.182.13.3846-3849.2000 ◽

2000 ◽

Vol 182 (13) ◽

pp. 3846-3849 ◽

Cited By ~ 20

Author(s):

Skorn Mongkolsuk ◽

Wirongrong Whangsuk ◽

Mayuree Fuangthong ◽

Suvit Loprasert

Keyword(s):

Amino Acid ◽

Xanthomonas Campestris ◽

Resistant Mutant ◽

The Other ◽

Single Amino Acid ◽

Silent Mutation ◽

Expression Vectors ◽

Nucleotide Sequence Analysis ◽

Wild Type ◽

Single Amino Acid Change

ABSTRACT A spontaneous Xanthomonas campestris pv. phaseoli H2O2-resistant mutant emerged upon selection with 1 mM H2O2. In this report, we show that growth of this mutant under noninducing conditions gave high levels of catalase, alkyl hydroperoxide reductase (AhpC and AhpF), and OxyR. The H2O2 resistance phenotype was abolished inoxyR-minus derivatives of the mutant, suggesting that elevated levels and mutations in oxyR were responsible for the phenotype. Nucleotide sequence analysis of the oxyRmutant showed three nucleotide changes. These changes resulted in one silent mutation and two amino acid changes, one at a highly conserved location (G197 to D197) and the other at a nonconserved location (L301 to R301) in OxyR. Furthermore, these mutations in oxyRaffected expression of genes in the oxyR regulon. Expression of an oxyR-regulated gene, ahpC, was used to monitor the redox state of OxyR. In the parental strain, a high level of wild-type OxyR repressed ahpC expression. By contrast, expression of oxyR5 from the X. campestris pv. phaseoli H2O2-resistant mutant and its derivative oxyR5G197D with a single-amino-acid change on expression vectors activatedahpC expression in the absence of inducer. The other single-amino-acid mutant derivative of oxyR5L301R had effects on ahpC expression similar to those of the wild-type oxyR. However, when the two single mutations were combined, as in oxyR5, these mutations had an additive effect on activation of ahpC expression.

Download Full-text

Natural isolates of Brome mosaic virus with the ability to move from cell to cell independently of coat protein

Journal of General Virology ◽

10.1099/vir.0.80775-0 ◽

2005 ◽

Vol 86 (4) ◽

pp. 1201-1211 ◽

Cited By ~ 8

Author(s):

Atsushi Takeda ◽

Wakako Nakamura ◽

Nobumitsu Sasaki ◽

Kaku Goto ◽

Masanori Kaido ◽

...

Keyword(s):

Coat Protein ◽

Mosaic Virus ◽

Mutational Analysis ◽

Cell Movement ◽

Plant Viruses ◽

Brome Mosaic Virus ◽

Single Amino Acid ◽

In Planta ◽

C Terminus ◽

Natural Isolates

Brome mosaic virus (BMV) requires encapsidation-competent coat protein (CP) for cell-to-cell movement and the 3a movement protein (MP) is involved in determining the CP requirement for BMV movement. However, these conclusions have been drawn by using BMV strain M1 (BMV-M1) and a related strain. Here, the ability of the MPs of five other natural BMV strains to mediate the movement of BMV-M1 in the absence of CP was tested. The MP of BMV M2 strain (BMV-M2) efficiently mediated the movement of CP-deficient BMV-M1 and the MPs of two other strains functioned similarly to some extent. Furthermore, BMV-M2 itself moved between cells independently of CP, demonstrating that BMV-M1 and -M2 use different movement modes. Reassortment between CP-deficient BMV-M1 and -M2 showed the involvement of RNA3 in determining the CP requirement for cell-to-cell movement and the involvement of RNAs 1 and 2 in movement efficiency and symptom induction in the absence of CP. Spontaneous BMV MP mutants generated in planta that exhibited CP-independent movement were also isolated and analysed. Comparison of the nucleotide differences of the MP genes of BMV-M1, the natural strains and mutants capable of CP-independent movement, together with further mutational analysis of BMV-M1 MP, revealed that single amino acid differences at the C terminus of MP are sufficient to alter the requirement for CP in the movement of BMV-M1. Based on these findings, a possible virus strategy in which a movement mode is selected in plant viruses to optimize viral infectivity in plants is discussed.

Download Full-text

Genetic variation of populations of Citrus psorosis virus

Journal of General Virology ◽

10.1099/vir.0.81742-0 ◽

2006 ◽

Vol 87 (10) ◽

pp. 3097-3102 ◽

Cited By ~ 26

Author(s):

Susana Martín ◽

María Laura García ◽

Antonella Troisi ◽

Luis Rubio ◽

Gonzalo Legarreta ◽

...

Keyword(s):

Genetic Variation ◽

Type Species ◽

Protein Gene ◽

Nucleotide Substitutions ◽

Coding Regions ◽

Citrus Psorosis Virus ◽

Selection For ◽

Genomic Regions ◽

Two Populations ◽

Amino Acid Sequence Conservation

Citrus psorosis virus (CPsV), the type species of genus Ophiovirus, has a segmented, negative-stranded RNA genome. We examined the population structure and genetic variation of CPsV in three coding regions located in RNAs 1, 2 and 3, analysing 22 isolates from Argentina, California, Florida, Italy and Spain. Most isolates contained a predominant sequence and some minor variants. Estimations of the genetic diversity and phylogenetic clustering of isolates disclosed two populations, one comprising isolates from Spain, Italy, Florida and California and the other including the Argentinean isolates. Isolate CPV-4 (from Texas) included for comparison was distant from both groups, suggesting that it belongs to a third group. The low ratio between non-synonymous and synonymous nucleotide substitutions indicated strong selection for amino acid sequence conservation, particularly in the coat protein gene. Incongruent phylogenetic relationships in different genomic regions suggested that exchange of genomic segments may have contributed to CPsV evolution.

Download Full-text

Coat protein gene-mediated resistance to Potato virus A in transgenic plants is suppressed following infection with another potyvirus

Journal of General Virology ◽

10.1099/0022-1317-82-9-2275 ◽

2001 ◽

Vol 82 (9) ◽

pp. 2275-2278 ◽

Cited By ~ 33

Author(s):

E. I. Savenkov ◽

J. P. T. Valkonen

Keyword(s):

Steady State ◽

Coat Protein ◽

Transgenic Plants ◽

Potato Virus ◽

Potato Virus Y ◽

Protein Gene ◽

Specific Resistance ◽

Virus Genome ◽

Potato Virus A ◽

Steady State Levels

High levels of resistance to Potato virus A (PVA, genus Potyvirus), indicated by absence of detectable infection in inoculated leaves, were attained in Nicotiana benthamiana transformed with a construct expressing the PVA 5′-untranslated region fused with the coat protein (CP)-encoding sequence. Low steady-state levels of the transgene transcripts were detected. Resistance was PVA-specific and did not protect the plants against infection with Potato virus Y (PVY, genus Potyvirus). Consequently, the steady-state levels of the CP-transgene mRNA were greatly elevated in the plants infected with PVY, and plants became susceptible to infection with PVA. These data show that virus resistance obtained by expressing regions of a plant virus genome in transgenic plants may be suppressed following infection with another virus that evades the virus-specific resistance.

Download Full-text

First identification of a single amino acid change in the spike protein region of feline coronavirus detected from a coronavirus-associated cutaneous nodule in a cat

Journal of Feline Medicine and Surgery Open Reports ◽

10.1177/2055116918801385 ◽

2018 ◽

Vol 4 (2) ◽

pp. 205511691880138

Author(s):

Takafumi Osumi ◽

Ikki Mitsui ◽

Christian M Leutenegger ◽

Ryo Okabe ◽

Kaori Ide ◽

...

Keyword(s):

Amino Acid ◽

Protein Gene ◽

Clinical Signs ◽

Spike Protein ◽

Single Amino Acid ◽

Molecular Diagnostic ◽

Rt Pcr ◽

Single Amino Acid Change ◽

Cutaneous Nodule ◽

Feline Coronavirus

Case summary A 32-month-old spayed female Singapura cat presented with a non-pruritic erythematous nodule on the upper lip. The cat also had multiple nodules in the liver but exhibited no other clinical signs consistent with classical feline infectious peritonitis (FIP), such as pleural effusion or ascites, uveitis or neurological symptoms. Histopathological and immunohistochemical analyses of the cutaneous nodule revealed pyogranulomatous dermatitis with intralesional macrophages laden with feline coronavirus (FCoV) antigen. Real-time reverse transcription (RT)-PCR of a cutaneous sample revealed a single nucleotide substitution in the spike protein gene of FCoV (mutation M1058L), which is consistent with an FCoV genotype commonly associated with FIP. The cat received a blood transfusion and supportive therapy, but the owner declined to continue the treatments owing to poor response. The cat was lost to follow-up 5 months after discharge. Relevance and novel information This report describes a case of a coronavirus-associated cutaneous nodule in which the evidence of amino acid changes in the spike protein gene identified by RT-PCR were consistent with an FCoV genotype commonly seen in cases of FIP. To the best of our knowledge, this is the first report of a case of cutaneous disease associated with the mutated FCoV that was confirmed by molecular diagnostic testing.

Download Full-text

Biological and Molecular Characterization of a Novel Tobamovirus with a Unique Host Range

Plant Disease ◽

10.1094/pdis.2003.87.10.1190 ◽

2003 ◽

Vol 87 (10) ◽

pp. 1190-1196 ◽

Cited By ~ 29

Author(s):

Scott Adkins ◽

Ivanka Kamenova ◽

Diann Achor ◽

Dennis J. Lewandowski

Keyword(s):

Coat Protein ◽

Host Range ◽

Protein Sequence ◽

Genome Organization ◽

Protein Gene ◽

Coat Protein Sequence ◽

Plant Viruses ◽

Experimental Host Range ◽

Solanaceous Plants

Tobamoviruses are among the best characterized and most studied plant viruses. Three subgroups of tobamoviruses correspond to viral genome sequence and host range to include those viruses infecting (i) solanaceous plants, (ii) brassicas, or (iii) cucurbits or legumes. We isolated a virus from Florida landscape plantings of the malvaceous plant hibiscus (Hibiscus rosasinensis) that appears to be a tobamovirus based upon its virion morphology, genome organization, and coat protein sequence. The experimental host range of this virus included five malvaceous species but excluded all tested brassica, cucurbit, and legume species and 12 of the 19 solanaceous species tested. The unique host range and comparison of coat protein gene and protein sequences with those of recognized tobamoviruses indicate that this is a novel to-bamovirus. A limited survey revealed that this virus is widespread in hibiscus and related species in the Florida landscape.

Download Full-text