論文 - 内田 勝久
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Effect of seasons and fishing ban period on umami-related and functional components of greeneye (Chlorophthalmus albatrossis) from Japanese coast 査読あり
Horie Ryohei, Imagawa Takumi, Uchida Katsuhisa, Taoka Yousuke, Tanaka Ryusuke
Journal of Food Composition and Analysis 139 107163 2025年3月
記述言語：英語 掲載種別：研究論文（学術雑誌）
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Gluconeogenesis in the extraembryonic yolk syncytial layer of the zebrafish embryo. 査読あり
Furukawa F, Aoyagi A, Sano K, Sameshima K, Goto M, Tseng YC, Ikeda D, Lin CC, Uchida K, Okumura SI, Yasumoto K, Jimbo M, Hwang PP
PNAS nexus 3 ( 4 ) pgae125 2024年4月
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Ishimaru M., Uchida K., Taoka Y., Matsumoto T., Tanaka R.
Journal of Aquatic Food Product Technology 33 ( 1 ) 33 - 48 2023年11月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Aquatic Food Product Technology
The chemical composition of muscles from Japanese eels cultured in hot-spring water was determined and compared with that of eels cultured in well water. The proximate composition did not differ significantly between the culture conditions, but the hepatosomatic indices of the hot-spring water eels were significantly higher than those of the well water eels. Amino acid levels were higher in the hot-spring water eels, and the carnosine content of the hot-spring eels was lower than that of the controls. Our results suggest that hot-spring water is a promising medium for eel culture, and its use may bring energy cost savings.
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Yasaka Y., Binh P.T., Hayami Y., Tanaka R., Uchida K., Taoka Y.
Fisheries Science 89 ( 1 ) 41 - 51 2023年1月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Fisheries Science
We focused on developing an epidemic prevention method for circulating masu salmon aquaculture using the probiotic Lactococcus lactis strain K-C2. This study aimed to evaluate the antibacterial activities of strain K-C2 against pathogens isolated from dead Yamame and masu salmon. First, we identified pathogenic bacteria that were isolated from dead masu salmon based on phylogenetic analysis of the 16S rRNA gene sequence and biological and biochemical characterization. The antibacterial activity of strain K-C2 against seven pathogenic strains isolated from dead masu salmon in this study and two strains of Aeromonas salmonicida previously isolated from dead Yamame was tested using a double agar plate method. The results of a BLAST search using 16S rRNA partial sequence data (1200–1300 bp) revealed that six of the former strains and one of the latter strains showed high similarity to Vibrio anguillarum and Tenacibaculum maritimum, respectively. Strain K-C2 showed antibacterial activity against all pathogenic bacteria. In this study, pathogenic bacteria were newly isolated from dead seawater-acclimated masu salmon, and strain K-C2 was found to have antibacterial effects against these pathogens.
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Miyanishi H., Uchida K.
Fishes 6 ( 2 ) 2021年6月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Fishes
In fishes, it is necessary to select a salinity environment suitable for survival. However, little is known about the mechanisms regarding detection and selection of salinity environments in fish. This study involved the establishment of a simple aquarium system in which fish can swim between freshwater (FW) and seawater (SW) in a single tank. In this tank, the lower level contained SW, the upper level contained FW, and the FW and SW levels were clearly separated as different salinity areas. Behavioral experiments of salinity environment selection using this simplified system to evaluate salinity preference showed that FW-acclimated medakas preferred FW to SW. In contrast, SW-acclimated medakas preferred SW to FW. These results indicate that euryhaline medakas prefer the saline habitats to which they are acclimated, when able to select the salinity environment. We identified the taste receptor type-2 and polycystic kidney disease 2-like 1 genes as possibly related to high-salinity taste in medaka. The expression of these genes increased at certain time points after SW challenges. In this study, we established an aquarium system to facilitate a simple experiment for salinity preference. Our results suggest that the medaka is good model for research related to seawater environment selection in fish.
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Irachi S, Hall DJ, Fleming MS, Maugars G, Björnsson BT, Dufour S, Uchida K, McCormick SD.
Molecular and Cellular Endocrinology. 519 111056 2021年1月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Molecular and Cellular Endocrinology
Seasonal timing is important for many critical life history events of vertebrates, and photoperiod is often used as a reliable seasonal cue. In mammals and birds, it has been established that a photoperiod-driven seasonal clock resides in the brain and pituitary, and is driven by increased levels of pituitary thyroid stimulating hormone (TSH) and brain type 2 iodothyronine deiodinase (DIO2), which leads to local increases in triiodothyronine (T3). In order to determine if a similar mechanism occurs in fish, we conducted photoperiod manipulations in anadromous (migratory) Atlantic salmon (Salmo salar) that use photoperiod to time the preparatory development of salinity tolerance which accompanies downstream migration in spring. Changing daylength from short days (light:dark (LD) 10:14) to long days (LD 16:8) for 20 days increased gill Na+/K+-ATPase (NKA) activity, gill NKAα1b abundance and plasma growth hormone (GH) levels that normally accompany increased salinity tolerance of salmon in spring. Long-day exposure resulted in five-fold increases in pituitary tshβb mRNA levels after 10 days and were sustained for at least 20 days. tshβb mRNA levels in the saccus vasculosus were low and not influenced by photoperiod. Increased daylength resulted in significant increases in dio2b mRNA levels in the hypothalamus and midbrain/optic tectum regions of the brain. The results are consistent with the presence of a photoperiod-driven seasonal clock in fish which involves pituitary TSH, brain DIO2 and the subsequent production of T3, supporting the hypothesis that this is a common feature of photoperiodic regulation of seasonality in vertebrates.
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宮崎県沿岸域における循環型サクラマス養殖体制の確立と地域水産業の活性化．
内田勝久
調査月報（一般財団法人みやぎん経済研究所） 325 2 - 8 2020年5月
記述言語：日本語 掲載種別：研究論文（大学，研究機関等紀要）
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Taoka Y., Nakamura M., Nagai S., Nagasaka N., Tanaka R., Uchida K.
Fermentation 5 ( 2 ) 2019年6月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Fermentation
© 2019 by the authors. Previously, we developed a novel production technique for giant masu salmon (GMS). This study aimed to develop a fish sauce from GMS to explore ways to efficiently utilize the salmon and to enrich the fish sauce with γ-aminobutyric acid (GABA) by microbial fermentation. The minced bodies of GMS were autolyzed by endogenous protease at 55 °C and 60 °C. During autolysis, the changes in total free amino acids and protein size was monitored by LC-MS and SDS-PAGE analysis, respectively. After 96 h, fish sauce was prepared by heating, and the amino acid composition was analyzed by LC-MS. To enrich the fish sauce with GABA, Lactobacillus plantarum strain N10 was added and incubated at 28 °C for 48 h. The total free amino acids content significantly increased for 96 h. SDS-PAGE analysis showed that major bands at 200 kDa and 48 kDa detected at 0 h gradually disappeared over time. The ratio of anserine to total amino acids in the fish sauce was approximately 36%. The concentration of GABA in the fish sauce significantly increased through the addition of strain N10. Thus, anserine-rich fish sauce could be quickly produced from GMS, and the fish sauce was enriched with GABA by microbial fermentation.
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日本比較内分泌学会主催シンポジウム「Bridge to a new generation: 時代をつなぐ研究を未来へ」を開催して
内田 勝久
比較内分泌学 45 ( 167 ) 85_1 - 85_1 2019年
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：日本比較内分泌学会
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Changes in glycogen concentration and gene expression levels of glycogen-metabolizing enzymes in muscle and liver of developing masu salmon. 査読あり
Fumiya Furukawa,Shotaro Irachi, Mugen Koyama, Otto Baba, Hajime Akimoto,Sei-ichi Okumura, Hirohiko Kagawa, Katsuhisa Uchida
Comp Biochem Physiol A Mol Integr Physiol 225 74 - 82 2018年11月
記述言語：英語 掲載種別：研究論文（学術雑誌）
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Assessment of the timing and degree of smolt development in southern populations of masu salmon Oncorhynchus masou 査読あり
INATANI Y, INENO T, SONE S, MATSUMOTO N, UCHIDA K, SHIMIZU M
Journal of Fish Biology 2018年4月
記述言語：英語 掲載種別：研究論文（学術雑誌）
DOI： 10.1111/jfb.13647
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Tanaka R., Uchida K., Ishimaru M., Ito M., Matsumoto N., Taoka Y., Hatate H.
Journal of Food Measurement and Characterization 12 ( 1 ) 200 - 208 2018年3月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Food Measurement and Characterization
© 2017, Springer Science+Business Media, LLC. A new system of aquaculture for landlocked masu salmon (Oncorhynchus masou masou) has recently been developed in the southern Kyushu Island, Miyazaki, Japan. In this system, moderately silvering fish (smolt salmon) are artificially transported from the freshwater aquaculture ponds to floating seawater fish preserve, and they are then aquacultured during winter season, starting from December to the following April. As a result, their growth and body mass were greatly increased (total length: 21.25 ± 1.04–37.80 ± 3.71 cm; body weight: 81.75 ± 19.91–632.00 ± 172.42 g; condition factor: 8.45 ± 1.44–11.4 ± 0.74). In addition, There was a marked increase in chemical components such as the lipid contents (35.0 ± 9.4–79.2 ± 6.7 mg/g muscle), α-tocopherol (29.0 ± 17.0–178.6 ± 15.0 μg/g muscle), astaxanthin (0.1 ± 0.1–15.2 ± 8.8 μg/g muscle), and anserine (4.75 ± 0.59–10.32 ± 2.68 mg/g muscle) in the seawater-reared landlocked masu salmon. Furthermore, the antioxidant activity of the water soluble extract from the seawater-reared landlocked masu salmon increased from 480.96 ± 79.295–848.99 ± 182.79 μmol Trolox equivalent/g tissue. This new system that involves a short period of aquaculture in seawater not only promotes the growth of landlocked masu salmon, but may also improve its nutritional components and antioxidant activity.
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Variation in the ontogeny of sex steroid levels between latitudinal populations of the medaka. 査読あり
Kawajiri M, Uchida K, Chiba H, Moriyama S, Yamahira K
Zoological Letters 2015年11月
記述言語：英語 掲載種別：研究論文（学術雑誌）
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Induction of Phosphoenolpyruvate Carboxykinase (PEPCK) during Acute Acidosis and Its Role in Acid Secretion by V-ATPase-Expressing Ionocytes. 査読あり
Fumiya Furukawa, Yung-Che Tseng, Sian-Tai Liu, Yi-Ling Chou, Ching-Chun Lin1, Po-Hsuan Sung, Katsuhisa Uchida, Li-Yih Lin, Pung-Pung Hwang
International Journal of Biological Sciences 11 ( 6 ) 712 - 725 2015年5月
記述言語：英語 掲載種別：研究論文（学術雑誌）
DOI： 10.7150/ijbs.11827
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Nishiyama M., Uchida K., Abe N., Nozaki M.
General and Comparative Endocrinology 212 1 - 9 2015年2月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：General and Comparative Endocrinology
© 2015 Elsevier Inc. Since hagfishes are considered the most primitive vertebrate known, extant or extinct, studies on their reproduction are indispensable for understanding phylogenetic aspects of vertebrate reproduction. However, little information is available on the endocrine regulation of the gonadal function in the hagfish. Based on EST analysis of the testis of the brown hagfish (Paramyxine atami), P450 side chain cleavage (CYP11A), which is the first and essential enzyme for steroidogenesis in jawed vertebrates, was cloned. The deduced amino acid sequence of hagfish CYP11A shows high identity to other animal forms especially in two functional domains, adrenodoxin binding domain and heme-binding domain. In the phylogenetic analysis, hagfish CYP11A forms a clade with the vertebrate CYP11A. Following the real-time PCR analysis, CYP11A mRNA expression levels were clearly correlated to the developmental stages of gonads in both sexes of the brown hagfish. By in situ hybridization, CYP11A mRNA signals were found in the theca cells of the ovarian follicles and Leydig cells and the tubule-boundary cells of the testis. These molecular and histological evidences are suggesting that CYP11A plays functional roles as a steroidogenic enzyme in gonadal development. Moreover, native GTH purified from hagfish pituitary stimulated the transcriptional levels of CYP11A in the organ-cultured testis in vitro, clearly suggesting that the steroidogenic activity of the hagfish is under the control of the pituitary GTH. It is suggested that vertebrates, during their early evolution, have established the pituitary-gonadal reproductive system.
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Scoliorhapis dianthus, a new species of sea cucumber (Apodida: Chiridotidae) from the Sea of Japan 査読あり
Solis-Marin F, Komatsu M, Soliman T, Uchida K, Shimotani T, Nozaki M
The Proceedings of the Biological Society of Washington 2014年8月
記述言語：英語 掲載種別：研究論文（学術雑誌）
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Relationships between plasma concentrations of sex steroid hormones and gonadal development in the brown hagfish, Paramyxine atami. 査読あり
Nishiyama M., Chiba H., Uchida K., Shimotani T., Nozaki M.
Zoollogical Science 2013年12月
記述言語：英語 掲載種別：研究論文（学術雑誌）
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Nozaki M., Uchida K., Honda K., Shimotani T., Nishiyama M.
General and Comparative Endocrinology 189 111 - 118 2013年8月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：General and Comparative Endocrinology
A single functional gonadotropin (GTH) comprising two subunits, α and β, was recently identified in the pituitary of brown hagfish (Paramyxine atami). Little is known about the feedback mechanisms that regulate these GTH subunits by sex steroids in the hagfish. The present study was designed to examine feedback effects of estradiol and testosterone on mRNA expression and protein expression of both GTHα and GTHβ subunits in the pituitary of the juvenile P. atami. Intraperitoneal administration of estradiol over the course of 27. days resulted in substantial accumulation of immunoreactive (ir)-GTHα and ir-GTHβ in the adenohypophysis, but testosterone treatments over 27. days had no effects on ir-GTHα or ir-GTHβ. Estradiol treatment for 1, 2, 4 or 14. days had no effect on GTHα mRNA levels. In contrast, after 2. days of estradiol treatment, GTHβ mRNA levels had increased significantly from baseline, while these levels were not affected after treatment over 1, 4, or 14. days. After 14. days of testosterone treatment, both GTHα and GTHβ mRNA levels had decreased significantly from baseline levels. These results indicate that estradiol acted primarily to suppress the secretion of GTH, and hence resulted in the accumulations of ir-GTHα and ir-GTHβ in the pituitary. On the other hand, testosterone appeared to suppress both the synthesis and the secretion of GTH. Thus, estradiol and testosterone probably differ in their effects on the regulation of pituitary GTH syn thesis and secretion in juvenile hagfish. © 2013 Elsevier Inc.
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Effects of estradiol or testosterone treatment on expression of gonadotropin subunit mRNAs and proteins in the pituitary of juvenile brown hagfish, Paramyxine atami. 査読あり
Nozaki M., Uchida K., Honda K., Shimotani T., Nishiyama M.
General and Comparative Endocrinology 189 111 - 118 2013年5月
記述言語：英語 掲載種別：研究論文（学術雑誌）
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Glycoprotein hormone in the pituitary of hagfish and its evolutionary implications. 招待あり 査読あり
Uchida K, Moriyama S, Sower SA, Nozaki M.
Fish Physiology Biochemistry. 39 75 - 83 2013年2月
記述言語：英語 掲載種別：研究論文（学術雑誌）