Complete genomic RNA sequence of the Polish <Emphasis Type="Italic">Pepino mosaic virus</Emphasis> isolate belonging to the US2 strain

We have determined the complete nucleotide and amino acid sequences of the Polish Pepino mosaic virus (PepMV) isolate marked as PepMV-PK. The PepMV-PK genome consists of a single positive-sense RNA strand of 6412-nucleotide-long that contains five open reading frames (ORFs). ORF1 encodes the putative viral polymerase (RdRp), ORFs 2–4 the triple gene block (TGB 1–3), and ORF5-coat protein CP. Two short untranslated regions flank the coding ones and there is a poly (A) tail at the 3′ end of the genomic RNA. Thus, the genome organization of PepMV-PK is that of a typical member of the genus Potexvirus. Phylogenetic analysis based on full-length genomes of PepMV sequences showed that PepMV-PK was most closely related to the Ch2 isolate from Chile. Comparison of PepMV-PK and Ch2 showed the following nucleotide identities: 98% for the RdRp, 99% for the CP genes, and 98, 99, and 98% for the TGB1, TGB2, and TBG3, respectively. This high level of nucleotide sequence identity between the Chilean and Polish PepMV-PK isolates suggest their common origin.     

A novel mycovirus from Clitocybe odora

The Ninth Report of the International Committee on Taxonomy of Viruses (ICTV) reports only a few species whose members replicate in fungi. Most of these mycoviruses are described to replicate in phytopathogenic and commercially cultivated fungi. A few reports describe virus-like symptoms and virus-like particles in non-cultivated basidiocarps such as Boletus edulis, Laccaria spp. and Cantharellus spp. However, viral sequences from non-cultivated Agaricomycotina are not available yet. In this report, I present a partial sequence of a virus found in Clitocybe odora (Bull.:Fr.) P. Kumm var. odora coding for a putative RNA-dependent RNA polymerase (RdRp) and a small 20-kDa ORF that may encode a coat protein (CP). The sequence of the putative RdRp (ORF 1) of C. odora clusters with those of the Tanathephorus cucumeris virus RdRp and the Tuber aestivum mitovirus RdRp. In addition to sequence homology, Tanathephorus cucumeris virus shows a similar codon usage and TA content in the 5'- and 3' non-translated regions, but it does not encode a putative CP. A viral DNA form proposed for Tanathephorus cucumeris virus was not found in Clitocybe odora. This viral sequence does not fit into any of the existing virus taxa.     

The nucleotide sequence and genome organization of Sclerophthora macrospora virus A

Sclerophthora macrospora virus A (SmV A) found in S. macrospora, the pathogenic fungus responsible for downy mildew of gramineous plants, is a small icosahedral virus containing three segments (RNAs 1, 2, and 3) of the positive-strand ssRNA genome. In the present study we report the complete nucleotide sequence of the SmV A genome. The viral genome RNA 1 consists of 2928 nucleotides (nt) and has two open reading frames (ORFs 1a and 1b). ORF 1a contains the motifs of RNA-directed RNA polymerase (RdRp). The function of ORF 1b is unknown. RNA 2 consists of 1981 nt and single ORF (ORF 2). ORF 2 encodes a capsid protein. RNA 3 consists of 977 nt but not any ORFs, suggesting it as a satellite RNA. The deduced amino acid sequence of ORF 1a shows some similarity to those of RdRp of certain positive-strand RNA viruses, especially to the members of the family Nodaviridae, and that of ORF 2 to CP of the members in the family Tombusviridae. The nucleotide sequence of RNA 3 shows a 40-nucleotide length of partial similarity to S. macrospora virus B (SmV B) RNA. The capsid of SmV A is composed of two capsid proteins, CP 1 (p43) and CP 2 (p39), both encoded in ORF 2. CP 2 is apparently derived from CP 1 via proteolytic cleavage at the N-terminus. The genome organization of SmV A is characteristic and distinct from those of other known fungal RNA viruses, including SmV B. These results suggest that SmV A should be classified into a new group of mycoviruses.     

Complete nucleotide sequence and genome organisation of grapevine Bulgarian latent virus

The complete genome sequence of grapevine Bulgarian latent virus (GBLV) has been determined. RNA-1 (7,452 nt in length) contains a single ORF of 6,285 nt, encoding a polyprotein with conserved motifs characteristic of the viral protease cofactor (Prot-cofact), the NTP-binding protein (NTP), the cysteine-like protease (Cyst-Prot) and the RNA-dependent RNA polymerase (RdRp) of members of the order Picornavirales and show high aa sequence identity with blackcurrant reversion virus (BRV, 64%). RNA-2 (5,821 nt) contains a single ORF of 4,500 nt, encoding a polyprotein in which the conserved motifs of the movement protein (MP) and coat protein (CP) have been identified. The GBLV CP aa sequence shows highest homology with that of blueberry leaf mottle virus (BLMoV, 68%). Both RNAs have a poly(A) tail and a NCR at the 3' and 5' termini, respectively. The results of this study confirm the classification of GBLV as a member of a distinct species in subgroup C of the genus Nepovirus.     

Complete nucleotide sequence of Nootka lupine vein-clearing virus

The complete genome sequence of Nootka lupine vein-clearing virus (NLVCV) was determined to be 4,172 nucleotides in length containing four open reading frames (ORFs) with a similar genetic organization of virus species in the genus Carmovirus, family Tombusviridae. The order and gene product size, starting from the 5'-proximal ORF consisted of: (1) polymerase/replicase gene, ORF1 (p27) and ORF1RT (readthrough) (p87), (2) movement proteins ORF2 (p7) and ORF3 (p9), and, (3) the 3'-proximal coat protein ORF4, (p37). The genomic 5'- and 3'-proximal termini contained a short (59 nt) and a relatively longer 405 nt untranslated region, respectively. The longer replicase gene product contained the GDD motif common to RNA-dependent RNA polymerases. Phylogenetically, NLVCV formed a subgroup with the following four carmoviruses when separately comparing the amino acids of the coat protein or replicase protein: Angelonia flower break virus (AnFBV), Carnation mottle virus (CarMV), Pelargonium flower break virus (PFBV), and Saguaro cactus virus (SgCV). Whole genome nucleotide analysis (percent identities) among the carmoviruses with NLVCV suggested a similar pattern. The species demarcation criteria in the genus Carmovirus for the amino acid sequence identity of the polymerase (<52%) and coat (<41%) protein genes restricted NLVCV as a distinct species, and instead, placed it as a tentative strain of CarMV, PFBV, or SgCV when both the polymerase and CP were used as the determining factors. In contrast, the species criteria that included different host ranges with no overlap and lack of serology relatedness between NLVCV and the carmoviruses, suggested that NLVCV was a distinct species. The relatively low cutoff percentages allowed for the polymerase and CP genes to dictate the inclusion/exclusion of a distinct carmovirus species should be reevaluated. Therefore, at this time we have concluded that NLVCV should be classified as a tentative new species in the genus Carmovirus, family Tombusviridae.     

Characterization of a novel single-stranded RNA mycovirus in Pleurotus ostreatus

A mycovirus, named oyster mushroom spherical virus (OMSV), was isolated from cultivated oyster mushrooms with a severe epidemic of oyster mushroom Die-back disease. OMSV was a 27-nm spherical virus encapsidating a single-stranded RNA (ssRNA) of 5.784 kb with a coat protein of approximately 28.5 kDa. The nucleotide sequence of the virus revealed that its genomic RNA was positive strand, containing 5784 bases with seven open reading frames (ORF). ORF1 had the motifs of RNA-dependent RNA polymerases (RdRp) and helicase. ORF2 encoded a coat protein. ORF3 to 7 could encode putative polypeptides of approximately 12, 12.5, 21, 14.5, and 23 kDa, respectively, but none of them showed significant similarity to any other known polypeptides. The 5' end of the viral RNA was uncapped and the 3' end was polyadenylated with 74 bases. Genomic structure and organization and the derived amino acid sequence of RdRp and helicase domain were similar to those of tymoviruses, a plant virus group.     

Nucleotide sequence of the genome of a citrus isolate of olive latent virus 1

Summary The 3699 nt genome of olive latent virus 1 (OLV-1), described years ago from Southern Italy as a putative sobemovirus, was completely sequenced. OLV-1 genomic RNA was not polyadenylated and had a structure virtually identical to that of species of theNecrovirus rather than theSobemovirus genus. Five open reading frames (ORFs) were identified, of which the 5-proximal encoded a 23 K protein and ended with an amber codon whose readthrough could yield a putative 82 K product. This polypeptide had extensive sequence similarity with polymerases of serotypes A and D of tobacco necrosis necrovirus (TNV-A and TNV-D) and species of the familyTombusviridae and related genera (Dianthovirus andMachlomovirus). Two small ORFs followed, which encoded polypeptides of 8 K and 6 K, respectively. The 6 K product had extensive homology with the comparable 6 K protein of TNV-A and was also related to the 11 K protein of shallot latent carlavirus, one of the triple block polypeptides involved in cell-to-cell virus movement. The 3-proximal ORF was in the same position as the coat protein (CP) cistron of necroviruses and encoded a 30 K product related to CP of both TNV-A and -D. Computer-assisted comparative analysis of structural and non-structural proteins of OLV-1, TNV-A and TNV-D disclosed an overall distant relationship between OLV-1 and TNV-D. OLV-1 genome appeared homologous to that of TNV-A, but differences from TNV-A were the absence of the small ORF downstream of the CP cistron and in the low degree of sequence identity in CP (39% aa identity). OLV-1 is serologically distantly related to TNV-A and even more distantly related to TNV-D. We propose that OLV-1 is a necrovirus species in its own right.The sequence data reported in this paper have been deposited in the EMBL database and given the accession number X85989.     

Molecular characterization of a dsRNA totivirus infecting the sclerotial parasite Coniothyrium minitans

The complete nucleotide sequence, 4975 bp, of the double-stranded RNA (dsRNA) mycovirus infecting the sclerotial parasite Coniothyrium minitans (CmRV) was determined. Sequence analysis revealed the occurrence of two overlapping open reading frames (ORFs): the 5'-proximal large ORF (ORF1; nucleotide positions 62-2389) encodes a putative coat protein (CP) with a predicted molecular mass of 80344 Da, and the 3'-proximal ORF (ORF2, nucleotide positions 2386-4875) encodes a putative RNA dependent RNA Polymerase (RdRp) with a predicted molecular mass of 82551 Da. The tetranucleotide AUGA at nucleotide positions 2386-2389 includes the predicted start codon of ORF2, which overlaps with the stop codon for ORF1. Based on genome organization and sequence analysis encoded proteins, the virus infecting C. minitans strain Chy-1, designated C. minitans RNA virus (CmRV), belongs to the family Totiviridae. Pairwise sequence comparisons of the deduced amino acid sequences encoded by CmRV as well as phylogentic analysis indicated that it is more closely related to the totiviruses that infect filamentous fungi than to those infecting protozoa, yeast and smut fungi. The role of CmRV in the abnormal phenotype associated with a variant of C. minitans is discussed.     

The complete nucleotide sequence and genome organization of Fig cryptic virus,a novel bipartite dsRNA virus infecting fig,widely distributed in the Mediterranean basin

Two double-stranded RNA (dsRNA) segments of a virus with a bipartite genome identified in fig (Ficus carica L.) and denoted Fig cryptic virus (FCV) were cloned and sequenced. Viral dsRNAs are 1696 bp (RNA-1) and 1415 bp (RNA-2) in size. RNA-1 contains a single ORF (1419 nt) potentially encoding a 54 kDa protein and comprising the conserved amino acid motifs of the RNA-dependent RNA polymerase (RdRp) domain of species of the genus Alphacryptovirus. Its full-length amino acid sequence has the highest identity with Raphanus sativus cryptic virus 2 (RsCV-2) (36%), Beet cryptic virus 3 (BCV-3) (36%) and Fragaria chiloensis cryptic virus (FCCV) (34%). RNA-2 has also a single ORF (1014 nt) coding for a polypeptide with a predicted molecular mass of 38 kDa, identified as the viral coat protein (CP). In a phylogenetic tree constructed with the amino acid sequences of the RdRp domain, FCV clusters in a clade comprising BCV-3 and a number of tentative species of the genus Alphacryptovirus. FCV is not mechanically transmissible. It was detected in fig orchards of six Mediterranean countries (Albania, Algeria, Italy, Lebanon, Syria and Tunisia) where it does not seem to induce a visible disease.     

Co-infection by two distinct totivirus-like double-stranded RNA elements in Chalara elegans (Thielaviopsis basicola)

A full-length cDNA clone was developed from a 5.3 kb double-stranded (ds) RNA element present in strain CKP of the plant pathogenic fungus Chalara elegans. The complete nucleotide sequence was 5310 bp in length and sequence analysis revealed that it contained three large putative open reading frames (ORFs). ORF1 was initiated at nucleotide position 329 and encoded a putative coat protein, which shared some homology (35-45% amino acid identity) to other dsRNAs in the family Totiviridae. Both ORF2 and ORF3 were initiated at nucleotide positions 2619 and 4071, respectively, and encoded a putative RNA-dependent RNA polymerase (RdRp). Sequence comparison using deduced amino acid sequences of both ORF2 and ORF3 revealed that all RdRp conserved motifs shared highest homology (41% identity) to that of SsRNA1 of Totiviridae. This dsRNA in C. elegans was designated Chalara elegans RNA Virus 1 (CeRV1). During the development of the full-length cDNA clone of CeRV1, several partial cDNA clones from an additional dsRNA fragment in strain CKP were obtained, which when aligned with each other, produced one linear fragment which was 2336 bp long. Northern blot and sequence analysis of this second clone showed it differed in sequence composition from CeRV1. This dsRNA in C. elegans was designated Chalara elegans RNA Virus 2 (CeRV2). Sequence analysis of CeRV2 showed it contained all conserved motifs and shared some homology (45% amino acid identity) to RdRp regions of Totiviridae. The nucleotide and amino acid sequences of the conserved motifs of the RdRp regions between CeRV1 and CeRV2 showed an identity of 56% and 50%, respectively. These findings suggest that co-infection of two distinct totivirus-like dsRNAs (CeRV1 and CeRV2) in C. elegans, a first report in this fungus. Transmission electron microscopy of strain CKP of C. elegans revealed the presence of putative virus-like particles in the cytoplasm, which were similar both in shape and size to viruses in the Totiviridae.     

A new potyvirus first isolated and identified from <Emphasis Type="Italic">Angelica sinensis</Emphasis>

A filamentous virus was isolated in Angelica sinensis (Angelica sinensis (Oliv.) Diels) which shows mosaic symptoms on leaves in Minxian, Gansu province, China. According to morphology and molecular biology properties, this virus, which has a flexuous rod-shaped particle about 750 nm in length and 12 nm in width, was assigned to the genus Potyvirus, family Potyviridae. Its coat protein (CP) shows high similarity with six other potyviruses by analysis of peptide mass fingerprinting (PMF). The 919 bp nucleotides of 3′ terminal covering partial CP gene and 3′-untranslated region was amplified by RT-PCR using degenerate primers which were designed according to the result of PMF. In sequence comparisons and phylogenetic analysis, the new isolate was found to be closely related to Japanese hornwort mosaic virus (JHMV), Konjak mosaic virus (KoMV), and Zantedeschia mosaic virus (ZaMV). The most closely related virus is JHMV03 (AB251346), with 96.59% aa and 87.60% nt identity to the isolate. All results suggest the presence of a new member of potyvirus, tentatively named Dang Gui strain of Japanese hornwort mosaic virus (JHMV-DG*). In our research the antiserum against the CP of JHMV-DG had also been prepared. To our knowledge, it is the first time that a potyvirus has been isolated and identified in Angelica sinensis. *Nucleotide sequence date reported appear in GenBank with the accession number EF157843.     

Molecular characterization and detection of a new closterovirus identified from blackcurrant by high-throughput sequencing

Two large contigs with high sequence similarities to several closteroviruses were identified by high-throughput sequencing from a blackcurrant plant. The complete genome of this new virus was determined to be 17,320 nucleotides. Its genome contains ten open reading frames (ORF) that include, in the 5′–3′ direction, a large ORF encoding a putative viral polyprotein (ORF 1a) and nine ORFs that encode RNA-dependent RNA polymerase (RdRp, ORF 1b), p6 (ORF 2), heat shock protein 70-like protein (Hsp70h, ORF 3), Hsp-90-like protein (p61, ORF 4), CP minor (ORF 5), CP (ORF 6), p17 (ORF 7), p11 (ORF 8), and p26 (ORF 9), respectively. BCCV-1 shares nucleotide sequence identities of 43–45% with other 9 closteroviruses at genome sequences. The amino acid sequence identities between BCCV-1 and the closteroviruses were 49–55% (RdRp), 37–41% (Hsp70h), 19–33% (p61), 26–38% (CPm), and 19–28% (CP), respectively. Phylogenetic analysis of Hsp70h sequences placed the new virus with members of genus Closterovirus in the same group. The results indicate that this new virus, which is provisionally named as Blackcurrant closterovirus 1, should represent a new species of the genus Closterovirus. A RT-PCR was developed and used to detect BCCV-1 in more germplasm accessions of Ribes spp.     

Sequence Analysis of the Glycoproteins of <Emphasis Type="Italic">Tomato Chlorotic Spot Virus</Emphasis> and <Emphasis Type="Italic">Groundnut Ringspot virus</Emphasis> and Comparison with other Tospoviruses

The tospoviruses Tomato chlorotic spot virus (TCSV) and Groundnut ringspot virus (GRSV) cause high economic losses in several vegetable crops in Brazil. The glycoprotein precursor coding sequence was still not available for these two viruses. In this study, the 3' 4kb M RNA of TCSV and GRSV genome was cloned and sequenced. The sequences were compiled with the available 5' region sequence (NS_M gene and 5' UTR) of the same isolates. The M RNA of TCSV was deduced as formed by 4,882 nucleotides, while of GRSV by 4,855 nucleotides. Both M RNA comprised two ORFs in an ambisense arrangement. The vcRNA ORF coded for viral glycoprotein (G1/G2) precursor of TCSV (128.46kDa) and for glycoprotein precursor of GRSV (128.16kDa). Comparison of the TCSV and GRSV glycoprotein precursor proteins with those of other tospoviruses showed the highest identity with Tomato spotted wilt virus (81 and 79%, respectively). The amino acid sequence comparison of glycoprotein precursor between TCSV and GRSV revealed a high identity of 92%. However, the nucleotide sequence of the M RNA intergenie region showed only 78%. Phylogenetic analysis was done based on glycoprotein precursor and on M RNA intergenic region of tospoviruses and parameters on tospovirus taxonomic classification were discussed.     

Genome Organization and Expression of the <Emphasis Type="Italic">Penicillium stoloniferum</Emphasis> Virus F

The complete sequences of three double-stranded (ds) RNAs (referred to F1, F2 and F3) of Penicillium stoloniferum virus F (PsV-F) were established. The F1 dsRNA was 1677 bp in length, and it contained one open reading frame (ORF) of 538 amino acids (molecular weight of 63 kDa, referred to P63), The F2 dsRNA was 1500 by in length, and also it contained one ORF of 420 amino acids (molecular weight of 46 kDa, referred to P46). The F3 dsRNA was 677 bp in length, but contained a small ORF with unknown function. A sequence motif of (5′-CGTAAAA-3′) was found only at the 5′ termini of the F1 and F2 dsRNAs, and a sequence motif of (5′-TAAAAAAAAA-3′) was found at the 3′ termini of all three dsRNA segments. The predicted amino acid sequence of F1 showed 38–48% sequence homology with the putative dsRNA-dependent RNA polymerases (RdRp) of dsRNA viruses, but the predicted amino acid of F2 showed no homology. Phylogenetic analysis using the RdRp sequences of the various Partitiviruses and Alphacryptoviruses revealed that PsV-F clustered well with Partitiviruses, but showed remote relationship with PsV-S. Near full-length and positive-sense single-stranded (ss) RNAs derived from the Fl, F2 and F3 dsRNAs were detected from the PsV-infected host cell. The expressed proteins of P63 and P46 showed a positive reaction against PsV-F antiserum, indicating P63 and P46 as RdRp and capsid protein, respectively. These results suggest that PsV-F can be a member of Partitivirus, but it is quite distinct from PsV-S electrophoretically, serologically and genetically, though both viruses coexist in the same cell.     

Molecular cloning and sequencing of the coat protein gene of a Nebraskan isolate of tobacco necrosis virus: the deduced coat protein sequence has only moderate homology with those of strain A and strain D

Summary A partial nucleotide sequence spanning the coat protein (CP) gene of a Nebraskan isolate of tobacco necrosis virus (TNV-NE) has been determined. The sequence contains at least four open reading frames (ORFs). The 5-terminal ORF encodes a protein that has 86% and 38% homology with the polymerases of strains A (TNV-A) and D (TNV-D), respectively. The second and third ORFs probably encode 10.7 kDa and 6.2 kDa proteins (p 10.7 and p 6.2). These are respectively 90% and 96% amino acid homologous encoded by similar ORFs in TNV-A but only 26% and 20% homologous with those in TNV-D. The fourth 3-proximal ORF encodes the 30.3 kDa CP. The amino acid sequence of TNV-NE CP is only 51% and 44% homologous to those of TNV-A and TNV-D, respectively. Thus, the CP genes of TNV-NE, TNV-A, and TNV-D are quite different. Like the sequences to the 5 side of the CP gene, that of TNV-NE is more closely related to TNV-A than to TNV-D.This study was a cooperative investigation of the ARS, USDA, and the Nebraska Agricultural Experiment Station, under Project 21-12. It is published as paper no. 10147, Journal Series, Nebraska Agricultural Experiment Station. The nucleotide sequence data reported in this paper have been entered in the GenBank databases under the accession number L 04261.     

Molecular characterization of two Chinese isolates of <Emphasis Type="Italic">Beet mosaic virus</Emphasis>

The complete genomic sequences of Beet mosaic virus Xinjiang (BtMV-XJ) and Inner Mongolia (BtMV-IM) isolates from China were determined and compared with US and German isolates, reported previously. Results showed that viral genome of the two isolates both comprise 9,591 nucleotides, and contain the large single open reading frame (ORF) encoding a single polyprotein of 3,085 amino acid residues, from which ten putative functional proteins may be produced by autolytic cleavage processing as the US (BtMV-Wa) and German (BtMV-G) isolates. Sequence comparisons showed that BtMV-XJ shared 89.8% and 98.3% overall nucleotide identity with BtMV-Wa and BtMV-G isolates, and BtMV-IM exhibited the overall identities of 91.6% and 93.8% with BtMV-Wa and BtMV-G, respectively. Further, analyses revealed that BtMV-XJ shared higher identities in almost every region to BtMV-G than to BtMV-Wa both at the nucleotide and the amino acid levels. While BtMV-IM in the regions (6,666–7,671 and 7,672–9,591) showed highest homology with BtMV-XJ and BtMV-G, especially, after nt 7,672 with similarity up to 99.2% with BtMV-G; the region (2,331–4,083) showed highest identity (98.0% nt identity) with BtMV-Wa. That suggested BtMV-XJ had a more close relationship to BtMV-G, while BtMV-IM was more likely to be a natural recombination virus. In addition, phylogenetic analysis of the available BtMV CP sequences showed that BtMV isolates fell into two distinct groups: Euroasia group (Europe and China) and America group (USA). To the best of our knowledge, this study reported the complete sequences of two BtMV isolates from Asia for the first time. H. Xiang and Y.-H. Han contributed equally to this paper.     

Molecular detection of novel astroviruses in wild and laboratory mice

Pooled fecal specimens collected from striped field mice (Apodemus agrarius), yellow-necked mice (Apodemus flavicollis), and bank voles (Myodes glareolus) and individual stool samples collected from laboratory mice were tested for the presence of picornaviruses and astroviruses. Picornavirus RNA was detected only in one striped field mouse sample pool, while astrovirus RNA was detected in two yellow-necked mouse sample pools and in six of the 121 laboratory mouse samples. In a 234-amino acid (aa) fragment of the viral RNA dependent RNA polymerase (RdRp), the wild mouse picornavirus revealed the closest homology to the canyon mouse (Peromyscus crinitus) (93?% aa) and canine kobuviruses (92?% aa) and to Aichi virus (88?% aa). The two astroviruses detected in the yellow-necked mouse samples shared 77?% aa homology with each other in the partial (125 aa) RdRp region, 61?C62?% aa homology with rat astroviruses and only 54?C58?% aa homology with the house mouse (Mus musculus) astrovirus strain USA/2008/M52. The six laboratory mouse astroviruses displayed 97?C100?% aa homology to each other, and shared 71?C77?% aa homology with the yellow-necked mouse astroviruses, 58?C59?% aa homology with rat astroviruses and 55?C56?% aa homology with strain USA/2008/M52. The sequence of a 3,263?bp genome segment including the partial ORF1b (RdRp), complete ORF2 (capsid precursor), and 3?? NTR of a research mouse astrovirus strain (TF18LM) was determined. The full-length ORF2 showed low identities (17?C34?% aa) with other members of the Mamastrovirus genus and only 17?% aa homology with the house mouse astrovirus strain USA/2008/M52, indicating that AstVs described in this study represent a novel Mamastrovirus species. The relevance of astrovirus infection and its effect on biomedical research conducted in mice needs to be investigated.     

Two unrelated double-stranded RNA molecule patterns in <Emphasis Type="Italic">Gremmeniella abietina</Emphasis> type A code for putative viruses of the families <Emphasis Type="Italic">Totiviridae</Emphasis> and <Emphasis Type="Italic">Partitiviridae</Emphasis>

Summary. Two double stranded (ds) RNA molecule patterns, probably of viral origin, were sequenced from Gremmeniella abietina var. abietina type A. The genome of Gremmeniella abietina RNA virus L1 (GaRV-L1) from isolate HR2 was 5133bp and contained two open reading frames (ORFs). The 5-proximal ORF coded for a putative coat protein (CP) and the 3-proximal ORF encoded putative RNA-dependent RNA polymerase (RdRp). GaRV-L1 had sequence similarities with a previously described totivirus (Helminthosporium victoriae 190S virus) and two unclassified members of family Totiviridae (Sphaeropsis sapinea RNA virus 1 and Sphaeropsis sapinea RNA virus 2). The genome of Gremmeniella abietina RNA virus MS1 (GaRV-MS1) from isolate C5 was composed of three dsRNA molecules coding for a putative RdRp (dsRNA1), a putative CP (dsRNA2) and protein of unknown function (dsRNA3). The lengths of these dsRNA molecules were 1782, 1586 and 1181bp, respectively. Sequence comparisons indicated that the GaRV-MS1 dsRNA pattern comprises a putative virus that is highly similar to Discula destructiva virus 1, Discula destructiva virus 2 and Fusarium solani virus 1 of the family Partitiviridae.