Induction of a cross-reactive antibody response to influenza virus M2 antigen in pigs by using a Sendai virus vector

Protecting pigs from simultaneous infection with avian, swine, and human influenza viruses would be an effective strategy to prevent the emergence of reassortants with pandemic potential. M2 protein is a candidate antigen for so-called 'universal vaccines,' which confer cross-protection to different influenza viruses in a strain- and subtype-independent manner. We tested whether a recombinant F gene-deleted Sendai virus vector that contained an M2 gene derived from an H5N1 avian influenza virus (SeV/ΔF/H5N1M2) could induce a cross-reactive antibody response to the extracellular domain of M2 protein (M2e) in pigs. SeV/ΔF/H5N1M2 induced an antibody response to M2e when the vector was inoculated intramuscularly. The antibodies induced by SeV/ΔF/H5N1M2 cross-reacted with M2e derived from different avian, swine, and human influenza viruses. In mice, however, SeV/ΔF/H5N1M2 did not confer cross-protection to challenge with a heterologous H3N2 influenza virus. Our results confirm those of other groups indicating that antibodies to M2e do not mediate protection to influenza viruses in pigs.     

Intraocular vaccination with an inactivated highly pathogenic avian influenza virus induces protective antibody responses in chickens

Because it is expected to induce cross-reactive serum and mucosal antibody responses, mucosal vaccination against highly pathogenic avian influenza (HPAI) is potentially superior to conventional parenteral vaccination. Here, we tested whether intraocular vaccination with an inactivated AI virus induced protective antibody responses in chickens. Chickens were inoculated intraocularly twice with 10⁴ hemagglutination units of an inactivated H5N1 HPAI virus. Four weeks after the second vaccination, the chickens were challenged with a lethal dose of the homologous H5N1 HPAI virus. Results showed that most of the vaccinated chickens mounted positive antibody responses. The median serum hemagglutination inhibition titer was 1:80. Addition of CpG oligodeoxynucleotide 2006 or cholera toxin to the vaccine did not enhance serum antibody titers. Cross-reactive anti-hemagglutinin IgG, but not IgA, was detected in oropharyngeal secretions. In accordance with these antibody results, most vaccinated chickens survived a lethal challenge with the H5N1 HPAI virus and did not shed the challenge virus in respiratory or digestive tract secretions. Our results show that intraocular vaccination with an inactivated AI virus induces not only systemic but also mucosal antibody responses and confers protection against HPAI in chickens.     

Molecular characterization of an H1N2 swine influenza virus isolated in Miyazaki, Japan, in 2006

Swine influenza virus (SIV) was isolated from a farm in Miyazaki Prefecture in Japan in July 2006. An isolate was genetically subtyped as H1N2 and was designated A/swine/Miyazaki/1/2006 (H1N2). The nucleotide sequences of all eight viral RNA segments were determined, and then phylogenetic analysis was performed using the neighbor-joining method. All segments were shown to be closely related to those of Japanese SIV H1N2 isolates, which have been circulating since the 1980s. The results indicate the persistence of the SIV H1N2 subtype in the Japanese pig population for more than two decades and emphasize the importance of continuous surveillance for SIV.     

Movements of dams milked for fermented horse milk production in Mongolia

Airag, (Fermented horse milk) is a traditional milk product in Mongolia. Herders separate foals from their dams and tie them at a milking site during the daytime to produce airag. To evaluate the effects of horse management on the movement of dams, we tracked three dams in a herd in camp 1 during summer and camp 2 during autumn of 2013 and analyzed their movements during the milking (daytime) and non‐milking (nighttime) periods in an area famous for its high‐quality airag. Dams were gathered every 1.7 ± 0.0 h between 07.46 and 15.47 hours at the milking sites and milked 4.6 ± 0.2 times/day during the study period (86 days). Daily cumulative and maximum linear distances from the milking sites were longer (P < 0.01) during the non‐milking period than during the milking period. Daily home ranges were 91 and 26 times greater during the non‐milking period (P < 0.001) in camps 1 and 2, respectively. The greater range during the non‐milking period would reflect the spatial distributions of water, salt and forage. The dams initially used similar areas and gradually shifted their daily home ranges after several days. This shift suggests that the dams grazed farther afield as forage availability declined around the milking site. For better airag production and sustainable pasture use, our results provide insights useful for evaluating the effects of milking management on vegetation and soil in those pastures, for selecting the appropriate milking times and frequency, and for choosing the right timing to shift milking sites.     

Chromosomal regions controlling anther culturability in rice (Oryza sativa L.)

Diallel analysis has revealed that anther culturability in rice (Oryza sativa L.) is a quantitative trait controlled by the nuclear genome. Mapping of anther culturability is important to increase the efficiency for green plant regeneration from microspores. In the previous study, we detected distorted segregation of RFLP markers in rice populations derived from the anther culture of an F₁ hybrid between a japonica cultivar ‘Nipponbare’ and an indica cultivar ‘Milyang 23’. To clarify the association between chromosomal regions showing distorted segregation and anther culturability, the anther culturability of doubled haploid lines derived from the same cross combination was examined, and the association between alleles of the RFLP markers, which exhibiting the most distorted segregation on chromosomes 1, 3, 7, 10 and 11, and the anther culturability was evaluated. One region on chromosome 1 was found to control callus formation from microspores, and one region on chromosome 10 appeared to control the ratio of green to albino regenerated plants. In both regions, the Nipponbare allele had positive effects. Three regions on chromosomes 3, 7 and 11, however, showed no significant effect on anther culturability. This revised version was published online in August 2006 with corrections to the Cover Date.     

Metagenomic analysis using 16S ribosomal RNA genes of a bacterial community in an urban stream,the Tama River,Tokyo

In an effort to determine genus- or species-level taxonomic profiles and diversity of bacterial consortia in the Tama River around urban Tokyo, next-generation sequencing technology targeting a 16S ribosomal RNA (rRNA) gene amplicon was employed. Metagenomic analysis performed by an Ion Personal Genome Machine after sequentially filtering samples through 5-, 0.8- and 0.2-μm filters yielded 1.48 Gb of 16S sequences (average 2.38 M reads/sample). The results indicated that half of the bacterial sequences belonged to Proteobacteria, followed by Bacteroidetes, Actinobacteria and Cyanobacteria. Flavobacterium (Bacteroidetes), possibly including a potential fish pathogen, was the most numerous genera in the Tama River metagenome, and accounted for?~?16% of assigned 16S reads, followed by Mycobacterium. Other dominant bacterial genera including Zoogloea, Sediminibacterium, Hyphomicrobium, Sphingopyxis, Thiothrix and Lysobacter, were thought to be associated with waste water and sludge. MiSeq metagenomic analysis revealed that environmental factors, particularly water temperature, influenced the bacterial composition throughout the year, with a strong negative correlation observed for Proteobacteria and a positive correlation for Bacteroidetes. In terms of bacterial genera, Flavobacterium was positively correlated with temperature, while Polaromonas, Pseudomonas and Bradyrhizobium were negatively correlated with this, suggesting dynamic change in the free-living bacterial population throughout the year and versatile adaptation strategies in relation to environmental factors.     

Long‐term changes in recruitment of age‐0 Pacific bluefin tuna (Thunnus orientalis) and environmental conditions around Japan

Recruitment of age‐0 Pacific bluefin tuna (Thunnus orientalis) from 1952 to 2014 was examined by a sequential regime shift detection method. The regime shifts in recruitment were detected in 1957, 1972, 1980, 1994 and 2009. The durations of regime shift ranged from 8–15 years and averaged 13.0 years. In both the total (1952–2014) and data rich (1980–2014) periods, negative relationships were found between recruitment and the Pacific Decadal Oscillation in autumn, and positive relationships were found between recruitment and sea surface temperature (SST) anomalies in the northern part of the East China Sea, in the southwestern part of the Sea of Japan, and in the waters off Shikoku and Tokai in summer and autumn. The 1994 and 2009 regime shifts in recruitment occurred in the same years as shifts in SST anomalies in the northern part of the East China Sea in summer. These results suggest that the ocean conditions in the northern part of the East China Sea are closely related to recruitment of Pacific bluefin tuna, and that the warmer conditions result in higher recruitment of the species.     

Relationship between albacore (Thunnus alalunga) fishing grounds in the Indian Ocean and the thermal environment revealed by cloud-free microwave sea surface temperature

Using cloud-free Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) sea surface temperature (SST) and daily set longline fishery data, we studied the relationship between albacore (ALB) fishing grounds and thermal conditions in the southern Indian Ocean. SST and Jensen-Shannon divergence (JSD) maps with a daily spatiotemporal resolution were related to sites with high catches per unit effort (CPUE) (>11 fish/10³ hooks). A high JSD is considered to be an index of a SST front. In winter, high CPUE occurred in the vicinity of the North Subtropical Front (Belkin and Gordon, 1996), where SST was 15-19 °C and JSD was 0.3-0.9. Histograms of the high CPUE plotted against SST and JSD indicated that 95% of the high CPUEs were in the 16-18.5 °C SST range and 97% were in the 0.4-0.9 JSD range. These ranges of SST and JSD are optimum ranges. These cloud-free SST/JSD analyses clearly demonstrate the seasonal north-south movement of the optimum SST and JSD band, which corresponds to the North Subtropical Front in the southern Indian Ocean. Monthly maps of joint probability density (JPD) with the optimum ranges of SST and JSD revealed that high CPUEs are located in the narrow bands with high JPD (>50%).