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71.
The external layer of a teleost fish scale is composed of type I collagen, an amorphous matrix substance and hydroxyapatite
crystals. Calcification of this layer can be inhibited in the scale-regenerating process under calcium- and phosphate-deficient
(CaDPD) conditions, and can be facilitated by incubation in physiological saline. The aim of this study was to evaluate this
model of calcification using histological and quantitative analysis in order to promote further understanding of the mechanism
of calcification in fish scales. We found that the external layer of the scales produced under CaDPD conditions contained
more densely aligned collagen fibrils with a small amount of the amorphous matrix substance. The CaDPD scale contained only
one-third of the amount of calcium and phosphate present in the control fish. After 4 hours of incubation, a two- to threefold
increase in calcium content and a 1.5-fold increase in phosphate content were observed. Calcification proceeded in the external
layer, and mineral deposits grew only in the electron-dense matrix substance. We conclude that this model would be suitable
for studying the early process of fish scale calcification that occurs in the noncollagenous substance. The electron-dense
substance may contain key molecules that promote calcification. 相似文献
72.
Muh Ali Arsyad Takashi Akazawa Chie Nozaki Makoto Yoshida Kenichi Oyama Tatsuo Mukai Masahiro Ogawa 《Fish physiology and biochemistry》2018,44(5):1299-1308
Olive leaf is known to have the high polyphenol content of 6–9% in dry weight. We investigated the effects of olive leaf powder (OLP) supplemented to fish feed on muscle protein of red sea bream (Pagrus major). Fish reared with feed containing 8% OLP for 40 days had 1.4 times higher myofibril content and 2.2 times higher acid-soluble collagen content than fish reared with control feed for the same period. On the other hand, sarcoplasmic protein content and collagenase activity of the muscle were almost the same between the control fish and OLP-diet fish. Microstructure observation of fish muscle showed that OLP-diet fish has more rigid endomysium structure than that of the control-diet fish. Since collagen fiber in endomysium is responsible for the texture of the muscle, feeding OLP to aquaculture fish will lead to a harder muscle texture. The present study suggests that OLP is a useful feed additive to enhance the texture of aquaculture red sea bream muscle through strengthening of the collagen structure in the muscle. 相似文献
73.
Maya Matsunami Toshinori Matsunami Ikuko Kodama Atsushi Ogawa Kyoko Toyofuku Junko Ishikawa-Sakurai 《Plant Production Science》2016,19(1):173-180
This study aimed to characterize the physiological and morphological traits that are associated with adaptation to unflooded soil conditions in rice. Four indica rice cultivars (Puluik Arang, Badari Dhan, Shwe Nang Gyi, and Ratul), which were previously identified as highly or less adaptable to unflooded soil conditions, were grown under flooded and unflooded (soil water potential; -0.10 MPa) soil conditions. Water uptake was measured every day for three weeks, and then the leaf water potential, the stomatal conductance, the dry matter weight, shoot and root morphological traits were measured. Puluik Arang and Badari Dhan exhibited greater leaf area expansion and higher maintenance of root development under the unflooded condition than that by other cultivars. The leaf water potential and stomatal conductance of fully expanded highest leaf in Puluik Arang and Badari Dhan were not affected by unflooded soil regime. Leaf area and root morphological traits were significantly correlated with water uptake regardless of soil moisture regimes. These results suggested that Puluik Arang and Badari Dhan exhibited great water uptake capacity through physiological and morphological adaptation of shoot and root traits to unflooded condition, resulting in great biomass productivity under the condition. 相似文献
74.
Imtiaj Hasan Shigeki Sugawara Yuki Fujii Yasuhiro Koide Daiki Terada Naoya Iimura Toshiyuki Fujiwara Keisuke G. Takahashi Nobuhiko Kojima Sultana Rajia Sarkar M. A. Kawsar Robert A. Kanaly Hideho Uchiyama Masahiro Hosono Yukiko Ogawa Hideaki Fujita Jiharu Hamako Taei Matsui Yasuhiro Ozeki 《Marine drugs》2015,13(12):7377-7389
MytiLec; a novel lectin isolated from the Mediterranean mussel (Mytilus galloprovincialis); shows strong binding affinity to globotriose (Gb3: Galα1-4Galβ1-4Glc). MytiLec revealed β-trefoil folding as also found in the ricin B-subunit type (R-type) lectin family, although the amino acid sequences were quite different. Classification of R-type lectin family members therefore needs to be based on conformation as well as on primary structure. MytiLec specifically killed Burkitt''s lymphoma Ramos cells, which express Gb3. Fluorescein-labeling assay revealed that MytiLec was incorporated inside the cells. MytiLec treatment of Ramos cells resulted in activation of both classical MAPK/ extracellular signal-regulated kinase and extracellular signal-regulated kinase (MEK-ERK) and stress-activated (p38 kinase and JNK) Mitogen-activated protein kinases (MAPK) pathways. In the cells, MytiLec treatment triggered expression of tumor necrosis factor (TNF)-α (a ligand of death receptor-dependent apoptosis) and activation of mitochondria-controlling caspase-9 (initiator caspase) and caspase-3 (activator caspase). Experiments using the specific MEK inhibitor U0126 showed that MytiLec-induced phosphorylation of the MEK-ERK pathway up-regulated expression of the cyclin-dependent kinase inhibitor p21, leading to cell cycle arrest and TNF-α production. Activation of caspase-3 by MytiLec appeared to be regulated by multiple different pathways. Our findings, taken together, indicate that the novel R-type lectin MytiLec initiates programmed cell death of Burkitt’s lymphoma cells through multiple pathways (MAPK cascade, death receptor signaling; caspase activation) based on interaction of the lectin with Gb3-containing glycosphingolipid-enriched microdomains on the cell surface. 相似文献
75.
A recent epidemic of the invasive monogenean Neoheterobothrium hirame is suspected to have caused the significant decline of the commercial catch of olive flounder, Paralichthys olivaceus, in Japan. To clarify the causal link between parasite invasion and host depletion, we monitored the infections of N. hirame on juvenile flounder for 2 years at two widely separate bays, Obama Bay, experiencing a devastating reduction in flounder catches, and Miyako Bay with a stable catch. Prevalence, mean intensity and abundance of developmental stages of N. hirame were compared between the bays and between fish year classes. Fishes captured at Obama Bay harboured three times more worms than those at Miyako Bay and had a significantly higher overall prevalence of infection. In addition, there was a negative correlation between parasite intensity and host condition factor at Obama Bay, suggesting a causal link between the N. hirame epidemic and the reduction of local flounder populations. 相似文献
76.
77.
Tetsuji Ogawa Shigeo Nakamura Mitsuru Sayama Kazusato Ohshima 《European journal of plant pathology / European Foundation for Plant Pathology》2013,135(4):745-760
We produced attenuated mutants of Potato virus Y necrotic strain not only by nitrous acid treatment but also by a novel method, probably unique to plant viruses, which we call the “mutagenesis-in-tissue culture method”. This relies on the natural or experimental generation of virus sequence variants within an infected plant, and then isolating the mutants by serially cloning them in plants. A total of fifteen attenuated mutants were obtained and studied. Nucleotide and amino acid sequences of the genomes of the attenuated mutant populations were compared with those parental severe isolates, and the amino acid changes in relevant genomic regions for viral attenuation were inferred. Many of the mutations were located in the 5’ half of the genome; 65 % were located in the protein 1 (P1) and helper component proteinase protein (HC-Pro) encoding regions. Amino acid changes mostly involved simultaneous changes in two or more protein encoding regions, one of which was often in the HC-Pro encoding region. The attenuated mutants M-MY10 and N-NA10 were effective in cross-protection against the original severe isolate NTND6. 相似文献
78.
Seventy-three breeding lines and cultivars, which included all Japanese cultivars, were assessed by random amplified polymorphic DNA (RAPD) analysis. Thirty-one of 40 decamer primers revealed 84 scorable RAPDs. Using these RAPDs, 67 of 73 cultivars were distinguished from each other. One of the cultivars released as a protoclonal variant was able to distinguish from the parent by increasing the number of primers surveyed. Based on the number of different RAPDs between each pair of accessions, cluster analysis was performed to exploit genetic diversity in Japanese cultivars. Closely related cultivars deduced from their pedigrees were clustered closely, indicating that similarities based on the presence vs. absence of RAPDs were reflections of genetic similarities. Old Japanese cultivars, as suggested by their similarity of chloroplast DNA toS. tuberosum ssp.andigena, were indeed clustered with ssp.andigena accessions, supporting these were relic cultivars of early European potatoes. The present study suggests that Japanese potatoes are an interesting mass of genetic diversity including North American, European, and Andean germplasms and relic potatoes. 相似文献
79.
Sugiyama A Kimura H Ogawa S Yokota K Takeuchi T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(5):673-678
The purpose of this study was to evaluate the effects of polyphenols from seed shells of Japanese horse chestnut (JHP) on methotrexate (MTX)-induced intestinal injury in rats. MTX application caused intestinal morphological injury and increase in malondialdehyde (MDA) levels, decrease in levels of glutathione (GSH) and glutathione peroxidase (GSH-Px) activities in small intestine. However, oral administration of JHP ameliorated MTX-induced intestinal injury and inhibited the increase in MDA and the decrease in GSH and GSH-Px activity in small intestine. In conclusion, our results indicated that oral administration of JHP alleviated MTX-induced intestinal injury through its antioxidant properties. 相似文献
80.
Ogawa H Sanada Y Sanada N Kudo M Tuchiya K Kodama T Uetsuka K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(6):837-840
A 5-month-old female Citron-crested Cockatoo (Cacatua sulphurea citrinocristata) that was born and hand-reared in Japan died with suspected proventricular dilatation disease (PDD). Macroscopic and microscopic examinations of the bird revealed characteristic features of PDD, i.e., distention of the proventriculus and infiltration of lymphocytes and plasma cells in ganglia of various organs and in central and peripheral nerves. A linkage of this PDD case to infection with avian bornavirus (ABV) was documented by RT-PCR amplification of the virus genomes from the affected bird. Phylogenetic analysis revealed that the ABV identified in this study clustered into the genotype 2, which is one of the dominant ABV genotypes worldwide. To the best of our knowledge, this is the first report of a natural case of PDD associated with ABV infection in Japan. 相似文献