Nationwide Cyprinid herpesvirus 3 contamination in natural rivers of Japan

Cyprinid herpesvirus 3 (CyHV-3) disease is a significant threat for common and koi carp cultivators and for freshwater ecosystems. To determine the prevalence of CyHV-3 in Japanese rivers, a nationwide survey of all national class-A rivers was undertaken in the Summer of 2008. The virus was concentrated from river water samples using the cation-coated filter method. CyHV-3 DNA was detected in 90 rivers, representing 90% of 103 successfully analysed rivers. More than 100,000 copies of CyHV-3 DNA per litre of sample were detected in four rivers, higher than that reported during the Yura River outbreak in 2007. For CyHV-3-positive rivers, the log CyHV-3 density was negatively correlated with the water temperature on the sampling date and positively correlated with the suspended solids and dissolved oxygen, which are annually averaged for each river. Our results demonstrate that virus detection using molecular biology techniques is a powerful tool for monitoring the presence of CyHV-3 in natural environments.     

Cytologically atypical anal sac adenocarcinoma in a dog

A 10-year-old intact female Shetland Sheepdog with tenesmus had a subcutaneous mass at the left ventral aspect of the anus. On cytologic examination, 2 types of cells were observed. Most of the cells were oval to polygonal and had elliptical or elongate nuclei and a moderate amount of pale to basophilic cytoplasm. The remaining cells had round to oval nuclei and pale to basophilic cytoplasm. Cells of both types were loosely adhered to each other and were arranged in rosette-like structures. Both neoplastic cell types had fine homogenous chromatin and either a small indistinct nucleolus or no visible nucleolus. Mild anisokaryosis and anisocytosis were observed. Histologically, the mass consists of glandular structures formed by cuboidal cells admixed with bundles of spindle cells. Eosinophilic PAS- and Alcian blue-positive secretory material was found in the center of some glandular structures. Both neoplastic cell types had positive staining with paradoxical concanavalin A and expressed cytokeratin, but not vimentin, S-100, α-smooth muscle actin, or desmin. Based on location and histologic and immunohistochemical features, the final diagnosis was adenocarcinoma of the apocrine gland of the anal sac, which should be included as a cytologic differential diagnosis when spindle cells and typical epithelial cells are observed in masses in the region of the anal sac of dogs.     

Relation of reproductive performances and rectal palpation for luteum function of heifers 7 days after estrus

Diagnosis of corpus luteum (CL) function by rectal palpation (RP) has been widely used for recipient selection of embryo transfer (ET), a technology essential for genetic improvements in cattle. To examine the accuracy of RP diagnosis method, the relationship between RP‐based CL function and reproductive performance was compared in this study. In Experiment 1, CL of Holstein heifers on day 7 after estrus was classified into functional or hypoplastic by RP, and the results were compared with ultrasonographic (US) images and plasma progesterone (P4) levels. As a result, heifers with functional CL judged by RP had a mean maximum CL diameter of 20.1 ± 3.1 mm on US and a mean P4 concentration of 8.1 ± 2.3 ng/mL. These values were significantly greater than those of heifers with hypoplastic CL (12.4 ± 5.4 mm, 4.0 ± 2.8 ng/mL) (P < 0.001). In Experiment 2, the length of the estrus cycle was examined between functional CL and hypoplastic CL. The rate of heifers with a normal estrus cycle length with 18–25 days was significantly lower with hypoplastic CL than with functional CL (16/24 vs. 43/46, P < 0.01). In Experiment 3, 543 inseminated heifers were similarly classified by CL function by RP 7 days after estrus. The heifers with functional CL showed higher pregnancy rate compared with the heifers with hypoplastic CL (75.2 vs. 47.9%, P < 0.0001). Finally, the CL function of 66 heifers was examined by RP on day 7 post‐estrus, and ET was performed in 49 (74.2%) heifers with functional CL. As a result, 27 (55.1%) of them became pregnant. Taken together, these results reconfirm that RP on day 7 after estrus is useful for selection of heifers with functional CL.     

Seasonal and interannual variation in net ecosystem production of an evergreen needleleaf forest in Japan

Carbon dioxide (CO₂) flux was measured above the forest at the Fujiyoshida site on the northern slope of Mount Fuji in Japan in 2000?C2008 using an eddy covariance technique. The forest mainly consists of Japanese red pine (Pinus densiflora) and Japanese holly (Ilex pedunculosa). The 9-year average of monthly mean net ecosystem production (NEP) ranged from ?0.1?g?C?m^?2?day^?1 in January to 2.5?g?C?m^?2?day^?1 in May. The maximum net uptake was observed in May, although gross primary production (GPP) was highest in July. Variation in the leaf amount did not notably affect seasonal variation in GPP. This site was characterized by carbon uptake even in winter, if the meteorological conditions were conducive for photosynthesis and a resulting long period of carbon uptake. The 9-year averages of annual NEP, GPP, and ecosystem respiration (RE) were 388, 1,802, and 1,413?g?C?m^?2?year^?1, respectively. The annual NEP was lowest in 2003 and highest in 2004 over the 9?years. Year-to-year variability of NEP mainly depended on air temperature and photosynthetically active radiation in summer, and the dependence of the deviation of annual NEP on that of GPP was greater than that of RE. Long-term observational data indicated that the carbon uptake ability at the study site was at a moderate level in comparison with other temperate humid evergreen forests around the world. These data also indicated that the site had a high carbon uptake ability compared with other deciduous forests in Japan because of the duration of carbon uptake.     

Genetic and enzymatic analyses of metalloprotease (aureolysin) from Staphylococcus aureus isolated from domestic animals.

The gene (aur) encoding the metalloprotease (aureolysin) of Staphylococcus aureus from domestic animals was analyzed by polymerase chain reaction (PCR), PCR-restriction fragment length polymorphism (PCR-RFLP) and sequencing. The aur gene was detected in all 74 isolates from cows, pigs and chickens by PCR amplification and was classified into types I and II by PCR-RFLP patterns. The type II aur gene was contained in 36 (94.7%) of 38 protease-positive isolates as judged by skim milk agar plate culture, while type I was contained in 28 (77.8%) of 36 protease-negative isolates. The deduced amino acid sequences of aureolysins from type I and II isolates were almost identical with those of the published data. Subsequently, the two aureolysins were purified from the culture supernatants of type I and II isolates. The molecular weights of purified type I and II aureolysins were both estimated at 34kDa by SDS-polyacrylamide gel electrophoresis. These aureolysins had maximum proteolytic activity at 30-50 degrees C and pH 7.0-8.0. Their activity was inhibited by metal- and zinc-specific inhibitors, such as EDTA, EGTA and 1,10-phenanthroline. Specific activity (activity/protein) of type II aureolysin was two times higher than that of type I. These results indicated that the aur gene is highly conserved with two allelic forms (types I and II) among bovine, porcine and avian isolates of S. aureus.     

Effects of late sowing on soybean yields and yield components in southwestern Japan

ABSTRACT

Soybean production in southwestern Japan tends to be unstable owing to wet soils during the rainy season. Although late sowing after the rainy season can avoid excess water, information on its yield potential is limited. The objective of this study was to reveal the effect of late sowing on yields and yield components of new soybean cultivars developed for warm regions. The experiment was conducted in 2016 and 2017 in Fukuyama, Hiroshima, Japan. Upland fields converted from paddy fields with a subirrigation system were planted in June (normal) or July (late sparse or late dense). Lodging was prevented with a net. The effects of late sowing and dense treatment were analyzed in relation to solar radiation use. In 2016, differences in yield among cultivars and among environments were not significant. In 2017, yield was significantly reduced following late sparse sowing. The total aboveground dry matter at maturity was correlated with total solar radiation intercepted (r = 0.76) but not with radiation use efficiency (r = 0.47). Late sowing increased harvest index (HI) significantly from 0.464 to 0.571 in 2016 and from 0.524 to 0.585 in 2017, but density had no significant effect. The changes in HI were correlated with stem dry weight (r = ?0.80 in 2016 and r = ?0.79 in 2017) rather than seed yield (r = 0.08, n.s. in 2016 and r = 0.19, n.s. in 2017). Thus, under irrigation, late dense sowing might stabilize yield in southwestern Japan because of higher HI.

Abbreviations: DM: dry matter; FOEAS: farm-oriented enhancing aquatic system; HI: harvest index; RUE: radiation use efficiency     

Effects of maturity genes E2 and E3 on yield formation in soybean cultivar Enrei in warm region,Fukuyama in Japan

ABSTRACT

Understanding how maturity genes affect soybean yield formation will provide important information for crop management decisions. This study aimed to reveal how maturity genes E2 and E3 in the soybean cultivar ‘Enrei’ affect yields and yield formation in warm regions of Japan. ‘Enrei’ (e2e3) and three near-isogenic lines of ‘Enrei’ (e2E3, E2e3, and E2E3) were cultivated in 2016 and 2017 in Fukuyama, Japan (34°30′N, 133°23′E). Two sowing dates were set in each year (June sowing and July sowing). E2 extended the period from emergence to R1 and also the period from R1 to R7, whereas E3 extended only the period from emergence to R1. Interaction between E2 and E3 did not affect duration of the period from emergence to R1, but did affect the period from R1 to R7. Although seed yield did not differ between genotypes in the June sowings, the effects of E2 and E3 on seed yield in July sowing were both significant and interaction between E2 and E3 also observed. The total number of nodes increased in E3 genotypes in both sowing dates, especially in E2E3. Pod-set ratio was lower in E2 and E3 genotypes than in e2 and e3 genotypes in the June sowings, but did not differ between genotypes in the July sowings. The high yield of E2E3 genotypes in the July sowings was attributed to increased number of nodes and flower production while maintaining pod-set ratio. Appropriate choice of sowing date is suggested to be essential when using E3 genotypes.Abbreviations: HI: harvest index; NIL: near-isogenic line; RUE: radiation use efficiency; TDM: total above-ground dry matter; TRI: total solar radiation intercepted     

Hypodectes propus (Acarina: Hypoderatidae) in a rufous turtle dove,Streptopelia orientalis (Aves: Columbiformes), in Japan

An adult male rufous turtle dove, Streptopelia (S.) orientalis (Aves: Columbiformes), was found dead in Yorii-machi Town, Osato District 369-1217, Saitama Prefecture, Japan, and subjected to necropsy. A large number of immobile hypopi (deutonymphs) of the hypoderatid mite, Hypodectes (H.) propus (Acarina: Hypoderatidae), were found individually encapsulated subcutaneously primarily in the adipose tissue. The mites were 1.43 mm in length and 0.44 mm in width on average, and had provoked mild inflammatory reactions that predominantly manifested as foamy macrophages and lymphoplasmocytes. PCR analysis using ribosomal DNA extracted from paraffin-blocked tissues produced a 240 bp band specific for hypoderatids. Based on the morphological features (distinct coxal apodemes, especially in the anterior portion) and PCR-based findings, the hypopi were identified as H. propus. To the best of our knowledge, this is the first case describing the subcutaneous mite H. propus in a rufous turtle dove, S. orientalis, in Japan. This study also highlights the use of paraffin blocks as a source of tissue DNA for molecular evaluation.