Antiproliferative and Antimicrobial Potentials of a Lectin from Aplysia kurodai (Sea Hare) Eggs

In recent years, there has been considerable interest in lectins from marine invertebrates. In this study, the biological activities of a lectin protein isolated from the eggs of Sea hare (Aplysia kurodai) were evaluated. The 40 kDa Aplysia kurodai egg lectin (or AKL-40) binds to D-galacturonic acid and D-galactose sugars similar to previously purified isotypes with various molecular weights (32/30 and 16 kDa). The N-terminal sequence of AKL-40 was similar to other sea hare egg lectins. The lectin was shown to be moderately toxic to brine shrimp nauplii, with an LC₅₀ value of 63.63 µg/mL. It agglutinated Ehrlich ascites carcinoma cells and reduced their growth, up to 58.3% in vivo when injected into Swiss albino mice at a rate of 2 mg/kg/day. The morphology of these cells apparently changed due to AKL-40, while the expression of apoptosis-related genes (p53, Bax, and Bcl-XL) suggested a possible apoptotic pathway of cell death. AKL-40 also inhibited the growth of human erythroleukemia cells, probably via activating the MAPK/ERK pathway, but did not affect human B-lymphoma cells (Raji) or rat basophilic leukemia cells (RBL-1). In vitro, lectin suppressed the growth of Ehrlich ascites carcinoma and U937 cells by 37.9% and 31.8%, respectively. Along with strong antifungal activity against Talaromyces verruculosus, AKL showed antibacterial activity against Staphylococcus aureus, Shigella sonnei, and Bacillus cereus whereas the growth of Escherichia coli was not affected by the lectin. This study explores the antiproliferative and antimicrobial potentials of AKL as well as its involvement in embryo defense of sea hare.     

Yield and growth characteristics of erect panicle type rice (Oryza sativa L.) cultivar,Shennong265 under various crop management practices in Western Japan

Erect panicle rice cultivars utilize solar energy effectively and have improved ecological growing conditions. Among such cultivars, Shennong265 has been grown successfully throughout Northern China. Nevertheless, no studies have yet examined the relationships between crop dry matter productivity, weather conditions, and nitrogen uptake of the erect panicle type rice cultivar in Japan. The objective of our study was to evaluate the productivity of erect panicle rice Shennong265 in Western Japan under varied conditions. Three rice cultivars, Shennong265, Nipponbare, and Takanari were grown in the field under different fertilizer and plant density conditions in Western Japan; using this information, we compared yield and growth characteristics of Shennong265 with those of Nipponbare and Takanari. Although Shennong265 had radiation use efficiency similar to that of the high yielding cultivar (Takanari) and much higher leaf nitrogen content than Takanari and Nipponbare, the average grain yield of Shennong265 grown under normal fertilizer and plant density conditions was approximately 6.9 t ha^?1 as against 6.2 t ha^?1 for Nipponbare and 9.6 t ha^?1 for Takanari. These results suggest that, while Shennong265 has a high yield potential, the environmental conditions including climate, fertilizer, and planting period provided in this study were not suitable for achieving its maximum yield. The reduced performance of Shennong265 may be caused by insufficient fertilizer after heading and by shorter growth periods, as well as by the climate of Western Japan. Additional fertilizer application during the heading stage and earlier transplanting may be needed to obtain higher Shennong265 yields in Western Japan.     

Anti‐tumour activity of oncolytic reovirus against canine histiocytic sarcoma cells

Canine histiocytic sarcoma is an aggressive, fatal neoplastic disease with a poor prognosis. Lomustine is generally accepted as the first‐line systemic therapy, although this compound does not provide complete regression. Therefore, research into a novel approach against canine histiocytic sarcoma is needed. However, anti‐tumour effects of oncolytic therapy using reovirus against histiocytic sarcoma are unknown. Here, we showed that reovirus has oncolytic activity in canine histiocytic sarcoma cell lines in vitro and in vivo. We found that reovirus can replicate and induce caspase‐dependent apoptosis in canine histiocytic sarcoma cell lines. A single intra‐tumoural injection of reovirus completely suppressed the growth of subcutaneously grafted tumours in NOD/SCID mice. Additionally, we demonstrated that susceptibility to reovirus‐induced cell death was attributable to the extent of expression of type I interferons induced by reovirus infection in vitro. In conclusion, oncolytic reovirus appears to be an effective treatment option for histiocytic sarcoma, and therefore warrants further investigation in early clinical trials.     

Construction of a linkage map based on retrotransposon insertion polymorphisms in sweetpotato via high-throughput sequencing

Sweetpotato (Ipomoea batatas L.) is an outcrossing hexaploid species with a large number of chromosomes (2n = 6x = 90). Although sweetpotato is one of the world’s most important crops, genetic analysis of the species has been hindered by its genetic complexity combined with the lack of a whole genome sequence. In the present study, we constructed a genetic linkage map based on retrotransposon insertion polymorphisms using a mapping population derived from a cross between ‘Purple Sweet Lord’ (PSL) and ‘90IDN-47’ cultivars. High-throughput sequencing and subsequent data analyses identified many Rtsp-1 retrotransposon insertion sites, and their allele dosages (simplex, duplex, triplex, or double-simplex) were determined based on segregation ratios in the mapping population. Using a pseudo-testcross strategy, 43 and 47 linkage groups were generated for PSL and 90IDN-47, respectively. Interestingly, most of these insertions (~90%) were present in a simplex manner, indicating their utility for linkage map construction in polyploid species. Additionally, our approach led to savings of time and labor for genotyping. Although the number of markers herein was insufficient for map-based cloning, our trial analysis exhibited the utility of retrotransposon-based markers for linkage map construction in sweetpotato.     

Distribution of Flavobacterium psychrophilum and its gyrA genotypes in a river

Fisheries Science - Flavobacterium psychrophilum can be divided into three genotypes, G-C type (ayu type), A-C type (multi-fish type), and A-T type (salmon-trout type), by two single-nucleotide...     

The use of machine learning to predict acute hepatopancreatic necrosis disease (AHPND) in shrimp farmed on the east coast of the Mekong Delta of Vietnam

Fisheries Science - Predicting the outbreak of disease is essential when managing shrimp farms. Acute hepatopancreatic necrosis disease (AHPND) caused by Vibrio parahaemolyticus is a serious...     

Effect of food amount and temperature on growth rate and aerobic scope of juvenile chum salmon

Offshore migration of Pacific salmon Oncorhynchus spp. is partly triggered by increasing body size and high motility in the early stages of life. The survival of juvenile salmon may depend on their growth rate during the first few months in the sea, and this factor partly regulates the dynamics of adult populations. Here, we assessed the effects of water temperature and food availability on the growth of juvenile chum salmon O. keta. In addition, by combining the measurements of metabolic performance for growth and activity (Absolute Aerobic Scope: AAS) with a bioenergetics model, we estimated the energy allocation for different activities in the juveniles. Under high temperatures (14 °C), juveniles reared at low food levels (1% body weight) allocated less than half their energy for growth than those reared at high food levels (4% body weight). These findings suggest that high temperature and low food level constrain the growth of juveniles, providing an insight into the effect of the recent increase in warm and low-nutrient water masses on survival of juveniles and catches of adult chum salmon on the Pacific side of Honshu Island, Japan.