Konjak mosaic virus: the complete nucleotide sequence of the genomic RNA and its comparison with other potyviruses.

Konjak mosaic virus (KoMV) belongs to the genus Potyvirus, family Potyviridae. The complete nucleotide sequence of KoMV F isolate (KoMV F) was determined. The genome is 9,544 nucleotides long excluding the 3' terminal poly A tail and encodes a typical potyviral 350-kDa polyprotein of 3,087 amino acids. Phylogenetic analysis using known potyvirus polyproteins shows that KoMV constitutes a branch with yam mosaic virus, close to another branch including Japanese yam mosaic virus, turnip mosaic virus, scallion mosaic virus and lettuce mosaic virus. The 3' terminal 1,842 nucleotides of a different isolate of KoMV, K-2, was also determined, covering the C-terminal 292 amino acids of the nuclear inclusion protein b (NIb), coat protein (CP), and the 3' untranslated region. The amino acid sequences of the KoMV F CP and the nucleotide sequences of the KoMV F 3' untranslated region showed 92.5 and 90.5% identity to the corresponding genes of K-2, 88.7-96.8 and 92.7-94.4% to those of Zantedeschia mosaic virus (ZaMV) isolates, 87.5-89.7% and 85.5-90.3% to those of Japanese hornwort mosaic virus (JHMV) isolates. These results showed that KoMV is a distinct potyvirus and that KoMV, ZaMV, and JHMV are members of the same potyvirus species. Considering that KoMV was the first of these to be described, ZaMV and JHMV may be considered isolates of KoMV.

Gentian mosaic virus: A New Species in the Genus Fabavirus.

ABSTRACT A viral isolate, designated N-1 and obtained from a gentian (Gentiana scabra) plant that exhibited mosaic symptoms, was transmitted mechanically to nine plant species in six families. These plants are known as hosts of fabaviruses. The N-1 isolate was composed of isometric particles 30 nm in diameter and included two RNA molecules of approximately 6.0 and 3.6 kb in length, as estimated by agarose gel electrophoresis. The RNAs were encapsidated separately in two of the three types of particle. Each particle contained two distinct proteins with Mr values of 39.3 x 10(3) and 26.6 x 10(3), as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Analysis of complete nucleotide sequences of the RNAs suggested that each encoded a single large polyprotein, in which putative functional proteins were arranged in a manner similar to those in Broad bean wilt virus 1 (BBWV-1) and Broad bean wilt virus 2 (BBWV-2), which are members of the genus Fabavirus (family Comoviridae). Analysis of the deduced amino acid sequences of the proteins indicated that those of isolate N-1 shared 38 to 66% identity with those of BBWV-1 and BBWV-2 but only 16 to 42% identity with those of a comovirus, Cowpea mosaic virus. Phylogenetic analysis, based on the amino acid sequences of RNA polymerase, placed isolate N-1 in a separate lineage from BBWV-1 and BBWV-2. In indirect-enzyme-linked immunosorbent assay, isolate N-1 exhibited distant serological relationship to BBWV-1, BBWV-2, and Lamium mild mosaic virus, another fabavirus. Our results suggest that N-1 represents a new species of Fabavirus. We propose the name Gentian mosaic virus for this new species.

Comparison of complete nucleotide sequences of genomic RNAs of four Soybean dwarf virus strains that differ in their vector specificity and symptom production.

Soybean dwarf virus (SbDV) is divided into four strains, namely YS, YP, DS and DP. YS and YP cause yellowing in soybeans, while DS and DP cause dwarfing. YS and DS are transmitted by Aulacorthum solani, while YP and DP are transmitted by Acyrthosiphon pisum. To clarify the taxonomic relationship between the four strains and to classify SbDV into an appropriate genus in the Luteoviridae, we determined the complete nucleotide sequences of genomic RNAs of four isolates belonging to each of the strains. The genomes of the four isolates had a chimeric form between Barley yellow dwarf virus-PAV and poleroviruses, and the genome organizations were similar to the Australian isolate SbDV Tas-1. In all of the non-coding regions and ORFs, nucleotide and deduced amino acid sequence identity between the same symptom-type strains was higher than that between the different symptom-type strains. However, in the N-terminal half of the readthrough domain (RTD) the deduced amino acid identity between the same aphid transmissibility-type strains was higher than that between the different aphid transmissibility-type strains. These data suggest that the N-terminal half of the RTD is closely related to the aphid transmission specificity, and that the present strains were generated from ancestral Y and D strains by mutations and strong selection pressures of efficient aphid transmission. Therefore, we propose that SbDV should be classified into a new genus in the family Luteoviridae and that the four strains described should be regarded as different strains of the same virus, rather than as distinct virus species.

Sequence analysis of RNA-2 of different isolates of broad bean wilt virus confirms the existence of two distinct species.

The complete nucleotide sequence of RNA-2 from a Japanese isolate IP of broad bean wilt virus (BBWV) was determined. The sequence encodes a single large polyprotein, which contains a putative movement protein and two coat proteins (CPs). The 3'-terminal sequences of RNA-2 were also determined for three other Japanese isolates and two ATCC isolates (PV132 and PV176) of BBWV. The CPs of the four Japanese isolates share 86.8-98.0% amino acid sequences homology with one another and 88.3-96.5% with those reported for the isolate PV131 (BBWV-2). However, they have only 57.9-66.2% homology with those of PV132 and PV176 (BBWV-1).

[Peri-focal administration of OK-432 combined with radiotherapy in the treatment of esophageal cancer].

We have been interested in direct activity of OK-432 on cancer lesion and applied a combined therapy of perifocal administration of OK-432 with radiation for 2 cases as a new trial. Following results were obtained. Histological efficacy as Ef3 at resected specimen was observed in one case and complete regression of cancer lesion was confirmed by X-ray, fiber scope and biopsy after combined therapy of perifocal administration of 10 KE of OK-432 with radiation of 2400 rad in total.