Detection of novel kobu-like viruses in Japanese black cattle in Japan

During surveillance for bovine diarrhea of unknown causes in Japanese black cattle in Kagoshima Prefecture, Japan, we found two types of novel kobu-like viruses in fecal samples of calves. Sequence analyses revealed that they had L protein and 2A protein with H-box/NC sequence motif, which are present in kobuviruses. Phylogenetic analysis revealed that they were related to kobuviruses; however, they clustered apart from other kobuviruses. In the prevalence study of two types of novel kobu-like viruses, 16.9% and 10.4% prevalence of these viruses were observed in the feces of diarrheal calves in this area.     

Possibility of Neospora caninum infection by venereal transmission in CB-17 scid mice

CB-17 scid and BALB/c male mice were inoculated intraperitoneally with Neospora caninum to examine the possibility of its venereal transmission. Some of these mice were killed on days 7 and 20 post-inoculation to examine the genital organs for presence of the parasite. The remaining scid male mice were housed with non-infected female mice from day 7 p.i. and kept with them for 14 days. These scid mice died between days 28 and 35 p.i. N. caninum DNA was detected in the testis of mice on days 7 and 20 p.i. by PCR and tachyzoite viability was determined by bioassay conducted by means of mouse inoculation. Microscopically, fewer tachyzoites were detected in the testis obtained on day 20 p.i., than in other organs. The inoculated BALB/c male mice survived until the end of the experiment with no clinical signs and N. caninum DNA was detected in the testis on day 7 p.i. but not on day 14 p.i. Five of eight female scid mice housed with infected males became pregnant. Tachyzoites were detected in three of these mice and their neonates (n=3, 5 and 13, respectively). In three non-pregnant mice, no parasite was detected. Two of the four female BALB/c mice housed with infected male scid mice became pregnant but the parasite was not detected in them or in the neonates (n=3 and 13, respectively). These results indicate that the tachyzoites were present in the genital organs of the immunodeficient mice from day 7 p.i. and suggest that transmission may occur through mating with male mice.     

Bioluminescence reporter assay system to monitor Arabidopsis MPK3 gene expression in response to infection by Botrytis cinerea

The Arabidopsis MPK3 gene product participates in disease resistance mediated by the MAP kinase cascade. The expression of the MPK3 gene is induced by pathogen inoculation and treatment with chemicals such as salicylic acid (SA) and methyl jasmonate (JA), but the detailed expression pattern of the MPK3 gene has been largely unknown. To investigate MPK3 gene expression in response to disease stress, we fused the MPK3 promoter to the firefly luciferase gene to create a real-time monitoring system for regulated gene expression in planta. The results of an in vivo reporter assay using transgenic Arabidopsis plants harboring MPK3::Fluc showed that the MPK3 promoter activity was induced by treatment with chemicals such as SA and benzo(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH), that induce defense gene expression. Inoculation with the fungal pathogen Botrytis cinerea resulted in systemic induction of MPK3::Fluc.