Anti-Brucella antibodies in seals at coastal locations of Hokkaido,Japan, with focus on life stages

The enzyme-linked immunosorbent assay (ELISA) was applied to detect antibodies against Brucella abortus in serum samples from four seal species at nine coastal locations of Hokkaido, Japan. These antibodies were detected in 27% (32/118) of Western Pacific harbor seals (Phoca vitulina stejnegeri) at Cape Erimo. The antibodies were observed in spotted seals (P. largha) in one out of six at Nemuro, in two out of three at Rebun Island, in one out of two at Bakkai, and in examined one at Soya. They were also found in respective examined one ribbon seal (Histriophoca fasciata) and one ringed seal (Pusa hispida) at Akkeshi. Harbor seals that tested positive were mostly yearlings (35%, 20/57) and juveniles (45%, 10/22), while only one pup (1/13) and one subadult (1/5) tested positive with low titers of the antibody; no antibodies were observed in adults (n=21). These results suggest that Brucella mainly infected harbor seals from the environment while weaning, and the bacteria were cleared during the early life stage of the seals. In spotted seals, however, antibodies were also detected in adults, suggesting that spotted seals could become infected with Brucella even as adults. It is also possible that a different, more persistent strain of Brucella may have infected the spotted seals.     

Genital mycobacteriosis caused by Mycobacterium marinum detected in two captive sharks by peptide nucleic acid–fluorescence in situ hybridization

Mycobacterium marinum is a prevalent nontuberculous mycobacterium (NTM)-infecting teleosts. Conversely, little is known about mycobacteriosis in elasmobranchs, and M. marinum infection has never been reported from the subclass. This study investigated the histopathological characteristics and localization of this mycobacterium through molecular analysis of two captive sharks, a scalloped hammerhead Sphyrna lewini and a Japanese bullhead shark Heterodontus japonicus, exhibited in the same aquarium tank. We detected genital mycobacteriosis caused by M. marinum infection using molecular analyses, including polymerase chain reaction (PCR) and DNA sequencing targeting the 60 kDa heat-shock protein gene (hsp65), and peptide nucleic acid–fluorescence in situ hybridization (PNA-FISH) targeting the 16S rRNA gene. Both sharks showed granulomas in connective tissues of the gonads without central necrosis or surrounding fibrous capsules, which is unlike the typical mycobacterial granulomas seen in teleosts. This study reveals that elasmobranchs can be aquatic hosts of M. marinum. Because M. marinum is a representative waterborne NTM and a potential zoonotic agent, cautious and intensive research is needed to overcome a lack of data on the relationship between NTM and the aquatic environment in association with this subclass of Chondrichthyes.     

Utility of a GFP-expressing Barley yellow mosaic virus for analyzing disease resistance genes

The soil-borne plasmodiophorid Polymyxa graminis is a vector for Barley yellow mosaic virus (BaYMV), which can severely damage barley plants. Although 22 disease resistance genes have been identified, only a few have been used for breeding virus-resistant cultivars. Recently, BaYMV strains capable of overcoming the effects of some of these genes have been detected. In this study, green fluorescent protein (GFP)-expressing BaYMV was constructed and used to examine viral dynamics in inoculated barley plants. Leaf inoculations resulted in higher infection rates than root or crown inoculations. Additionally, inoculations of some resistant cultivars produced infections that were similar to those observed in a field test. The results of this study indicate that the GFP-expressing virus is a useful tool for visualizing virus replication and dynamics, and for understanding resistance mechanisms.     

Genetic differentiation between local populations of Ips typographus in the high Tatra Mountains range

Many studies have addressed the question of dispersal potential of Ips typographus, however the approach of molecular ecology have been used only in a few of them. Moreover, none of them has done it on fine scale of just one mountain range. Molecular analysis using a set of six polymorphic microsatellite markers was applied in this study. Adult beetles of I. typographus collected in 22 localities of the High Tatra Mountains were used for the study of genetic differentiation between rapidly expanded local populations of bark beetles after windstorm calamities in spruce stands. Almost none genetic differentiation among local populations or among larger spatial units has been revealed. Analyses did not indicate isolation of populations by distance or formation of population structure. This suggests high potential of I. typographus to disperse over large distances and even the possibility to overcome high mountains ridges.     

Lessons from Two Case Studies of Implementing Traceability in the Dried Salted Fish Industry

The traceability practices in two companies representative of those in a supply chain—one a producer of wet salted cod, the other of dried salted cod—were systematically investigated by a standard procedure. Neither company retained batch identities for all steps in the production process, and so, they did not have an effective traceability system. Although production of dried salted fish is challenging due to the many transformations taking place during production, the use of the basic technique of applying and recording unique identifiers could have provided a traceability system from delivery of wet fish through to the final dried product. This study focused on the critical points for traceability during production of both wet and dried salted fish and the practical challenges this presented.     

Comparative Immunolocalization of GLUTs 1, 2, 3 and 5 in Boar,Stallion and Dog Spermatozoa

Spermatozoa, as other eukaryotic cells, need hexoses to produce energy to maintain membrane homeostasis, to move along the female genital tract and to carry the male genome to the female gamete. GLUTs are a family of proteins that permit and improve the passive transport of hexoses inside cells. This study was aimed at investigating the presence and localization of GLUTs 1, 2, 3 and 5 in boar, stallion and dog spermatozoa by both immunofluorescence and western blotting. GLUTs exhibited a peculiar distribution along the sperm cell depending on the isoforms considered, the hexose they transport and the different species. The localization of GLUTs after capacitation and acrosome reaction highlighted the possible changes in their distribution because of the different functional moment. Only in dog spermatozoa changes in GLUTs distribution were demonstrated; these changes could be related to the different metabolic needs and modifications occurring in the sperm cell.     

Amplified fragment length polymorphism (AFLP) markers for fingerprinting of Argyranthemum frutescens cultivars

Argyranthemum frutescens is a commercially important ornamental species with extensive breeding programmes in several countries. Since it is vegetatively propagated there is a great need for tools for identification of cultivars. Vegetatively propagated species require clean-up from diseases, often performed through meristem-tip cultures. Forty-three cultivars of A. frutescens propagated by meristem-tip culture and traditional cuttings were analyzed for genetic relatedness and possible somaclonal variation using AFLP. Five primer combinations resulted in a relatively high degree of polymorphism. Ten molecular markers generated by one primer combination could distinguish between all 43 cultivars. Differences in fingerprints between meristem-tip culture and cuttings from the same cultivars were found, but the proportion of fragments being specific for either tissue culture or cuttings was relatively low. Some cultivars that did not display somaclonal variation as judged by the AFLP-fingerprints may still be genetically unstable since some morphological variation was observed in the true to type test.     

Positive association between understory species richness and a dominant shrub species (Corylus avellana) in a boreonemoral spruce forest

Old growth stands of boreonemoral spruce (Picea abies) forests frequently have a shrub layer dominated by hazel (Corylus avellana) – a species which is generally excluded in intensively managed forests due to clearcutting activities. We sampled understory species composition, richness and biomass, as well as environmental variables beneath these two species and also within forest ‘gaps’ in order to determine the effect of overstory species on understory vegetation. Species richness and biomass of herbaceous plants was significantly greater under Corylus compared with plots under Picea and in forest gaps. Indicator species analysis found that many species were significantly associated with Corylus. We found 45% of the total species found under woody plants occurred exclusively under Corylus. Light availability in spring and summer was higher in gaps than under forest cover but no difference was found between plots under Corylus and Picea. Hence, reductions in light availability cannot explain the differences in species composition. However, Ellenberg indicator values showed that more light demanding species were found under Corylus compared to Picea, but most light demanding species were found in gaps. The litter layer under Picea was three times thicker than under Corylus and this may be an important mechanism determining differences in understory composition and richness between the woody species. The presence of Corylus is an important factor enhancing local diversity and small-scale species variation within coniferous stands. Hence, management should maintain areas of Corylus shrubs to maintain understory species diversity in boreal forests.