• Development and Reproduction
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• v.25 no.4
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• pp.225-234
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• 2021

The present study aimed to investigate the mechanism of cell surface receptor loss by two constitutively activating mutants (designated L469R, and D590Y) and two inactivating mutants (D417N and Y558F) of the luteinizing hormone receptor (LHR) in the Japanese eel Anguilla japonica, known to naturally occur in human LHR transmembrane domains. We investigated cell surface receptor loss using an enzyme-linked immunosorbent assay in HEK 293 cells. The expression level of wild-type eel LHR was considered to be 100%, and the expression levels of L469R and D417N were 97% and 101%, respectively, whereas the expression levels of D590Y and Y558F slightly increased to approximately 110% and 106%, respectively. The constitutively activating mutants L469R and D590Y exhibited a decrease in cell surface loss in a manner similar to that of wild-type eel LHR. The rates of loss of cell surface agonist-receptor complexes were observed to be very rapid (2.6-6.2 min) in both the wild-type eel LHR and activating mutants. However, cell surface receptor loss in the cells expressing inactivating mutants D417N and Y558F was slightly observed in the cells expressing inactivating mutants D417N and Y558F, despite treatment with a high concentration of agonist. These results provide important information on LHR function in fish and the regulation of mutations of highly conserved amino acids in glycoprotein hormone receptors.

• Development and Reproduction
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• v.25 no.3
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• pp.133-143
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• 2021

In contrast to the human lutropin receptor (hLHR) and rat LHR (rLHR), very few naturally occurring mutants in other mammalian species have been identified. The present study aimed to delineate the mechanism of signal transduction by three constitutively activating mutants (designated M410T, L469R, and D590Y) and two inactivating mutants (D383N and Y546F) of the eel LHR, known to be naturally occurring in human LHR transmembrane domains. The mutants were constructed and measured cyclic adenosine monophosphate (cAMP) accumulation via homogeneous time-resolved fluorescence assays in Chinese hamster ovary (CHO)-K1 cells. The activating mutant cells expressing eel LHR-M410T, L469R, and D590Y exhibited a 4.0-, 19.1-, and 7.8-fold increase in basal cAMP response without agonist treatment, respectively. However, inactivating mutant cells expressing D417N and Y558F did not completely impaired signal transduction. Specifically, signal transduction in the cells expressing activating mutant L469R was not occurred with a further ligand stimulation, showing that the maximal response exhibited approximately 53% of those of wild type receptor. Our results suggested that the constitutively activating mutants of the eel LHR consistently occurred without agonist treatment. These results provide important information of LHR function in fish and regulation with regard to mutations of highly conserved amino acids in glycoprotein hormone receptors.

• Journal of Animal Science and Technology
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• v.64 no.1
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• pp.123-134
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• 2022

Toll-like receptors (TLRs), as a part of innate immunity, plays an important role in detecting pathogenic molecular patterns (PAMPs) which are structural components or product of pathogens and initiate host defense systems or innate immunity. Precise negative feedback regulations of TLR signaling are important in maintaining homeostasis to prevent tissue damage by uncontrolled inflammation during innate immune responses. In this study, we identified and characterized the function of the pancreatic progenitor cell differentiation and proliferation factor (PPDPF) as a negative regulator for TLR signal-mediated inflammation in chicken. Bioinformatics analysis showed that the structure of chicken PPDPF evolutionarily conserved amino acid sequences with domains, i.e., SH3 binding sites and CDC-like kinase 2 (CLK2) binding sites, suggesting that relevant signaling pathways might contribute to suppression of inflammation. Our results showed that stimulation with polyinosinic:polycytidylic acids (Poly [I:C]), a synthetic agonist for TLR3 signaling, increased the mRNA expression of PPDPF in chicken fibroblasts DF-1 but not in chicken macrophage-like cells HD11. In addition, the expression of pro-inflammatory genes stimulated by Poly(I:C) were reduced in DF-1 cells which overexpress PPDPF. Future studies warrant to reveal the molecular mechanisms responsible for the anti-inflammatory capacity of PPDPF in chicken as well as a potential target for controlling viral resistance.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.791-801
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• 2022

Boil-dried concentrates (BDC) and steam-dried concentrates (SDC) were prepared from highly nutritious olive flounder Paralichthys olivaceus roes (OFR) as seafood processing by-products and their nutritional characteristics were investigated. Although SDS-PAGE profiles of the BDC and SDC proteins were similar to each other, it was observed that three of the five OFR protein bands in the 50-100 kDa range had disappeared. We also detected significant differences in the Hunter's color of the two concentrates in terms of color difference (𝚫E) and whiteness. The recovery amounts of BDC and SDC prepared from 100 g of OFR were 18.6 and 21.4 g, respectively, with respective protein contents of 67.7% and 68.9%. The main amino acids of OFR and concentrate proteins were valine, leucine, lysine, arginine, aspartic acid, glutamic acid and alanine, whereas major minerals were sulfur, potassium, sodium and phosphorus, the amounts of which in concentrates had been significantly reduced. We established that by sterilizing, inactivating endogenous enzymes, and inhibiting microbial growth, the cook-dried process contributes to enhancing the concentration and storage stability of nutrients by reducing water activity, volume, and weight. Accordingly, we suggest that concentrates (BDC and SDC) prepared from OFR have considerable potential as nutritionally fortified materials.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.808-816
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• 2022

This study was conducted with a view toward enhancing the industrial utilization of a male sailfin sandfish Arctoscopus japonicus based on its application in the preparation of Sik-hae, a Korean traditional fermented fishery product prepared using hard-boiled rice and enzymatic malt sprouts. As an alternative to rice and malt sprouts, we evaluated the utility of rice Koji for Sik-hae fermentation by investigating the physicochemical changes that occur during fermentation. The sailfin sand fish Sik-hae fermented with 10% or 20% rice Koji was found to show similar fermentation characteristics to the control fermentation with 20% hard-boiled rice and 4% malt sprouts, with respect to acid production, texture profile, and the softening of bones during the entire fermentation period. In particular, compared with the control, the addition of 10% rice Koji reduced the dehydration of Sik-hae and increased the content of free amino acids, which contributed to preventing a marked reduction in pH during fermentation. Accordingly, 10% rice Koji is proposed as a viable alternative enzymatic agent for the preparation of Sik-hae, which can contribute enhancing the desired properties of this traditional food product.

• Nutrition Research and Practice
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• v.16 no.4
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• pp.450-463
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• 2022

BACKGROUND/OBJECTIVES: Adolescents who skip breakfast have an increased prevalence of chronic diseases. Thus, we aimed to evaluate whether the intake of rice-based breakfast had positive effects on blood glucose indices and to determine the possibility of diabetes prevalence in Korean youths who habitually skip breakfast. SUBJECTS/METHODS: In this randomized parallel-group controlled trial, 81 subjects who were suitable for compliance among 105 middle-and high-school students aged 12-18 years who usually skipped breakfast were included in this study (rice-meal group [RMG], n = 26; wheat-meal group [WMG], n = 29; general-meal group [GMG], n = 26). The RMG and WMG received a rice-based breakfast and a wheat-based breakfast for 12 weeks, respectively. The anthropometric indices, blood glucose indices, and metabolites were measured at baseline and the endpoint, respectively. RESULTS: The mean body weights in the RMG, WMG, and GMG groups at the endpoint were 62.44 kg, 61.80 kg, and 60.28 kg, respectively, and the mean body weights of the WMG and GMG groups at the endpoint were significantly higher than that at baseline (P < 0.05). The levels of fasting insulin and homeostasis model assessment of insulin resistance (HOMA-IR) values were significantly decreased in the RMG group at the endpoint compared to baseline (P < 0.05, P < 0.05, respectively). The levels of tryptophan and tyrosine in the WMG group at the endpoint were significantly higher than that those at baseline (P < 0.01, P < 0.05, respectively). CONCLUSIONS: Rice-based breakfast has positive effects on fasting insulin levels and HOMA-IR in Korean adolescents who skip breakfast. Additionally, it was found that a skipping breakfast could increase the prevalence of diabetes in adolescents who skip breakfast. Therefore, in addition to reducing breakfast skipping, it is vital to develop a rice-based menu that fits teenage preferences to prevent chronic diseases such as diabetes.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.s01
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• pp.39-47
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• 1988

Soybean grain is most widely used and soybean crop produces most high protein per area among crops. To meet rapid increase of human population and supply protein in safety. soybean has considered more and more important crop. And it has been emphasizing that high quality and high protein soybean breeding must be made efforts in future. Many papers related to soybean breeding for high quality and protein and soybean protein composition have suggested the problems to do in future. Soybean germplasm collection. classification and conservation should be continuously performed, and it is emphasized that wild type of soybeans (G. soja) be considered to use in breeding for high protein varieties. Selections would be better emphasized in first yield and therefore high yield of protein per area. Selection for high protein would be secondary criterion. High protein lines with high yielding potential could be selection from certain populations, and breeders should consider this phenomenon in procedure of selection. Heritability of protein percent is relatively high and genetic gain of increment of protein percent is large. Soybean protein which is comprised 70 to 90% of globulin is constituted mostly 11S and 7S proteins. Sulfur-containing amino acids, methionine and cysteine, are identified to contain more in 11S protein than 7S protein. High 11S germplasm should be desirable to use in crossing plan, and selection of high ratio of 11S/7S lines be better in development of high quality varieties.

• Animal Bioscience
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• v.36 no.3
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• pp.471-483
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• 2023

Objective: This study was conducted to evaluate the interactive effects of dietary digestible tryptophan (dTry) and soy oligosaccharides (SO) on growth performance, caecal skatole level, and microflora of broiler chickens aged from 14 to 42 days. Methods: Three hundred and sixty broiler chicks were allocated equally to 36 cages at 14-day-of-age according to body weight and gender. Using a 3×2 factorial arrangement, 3 dietary dTry levels (0.18%, 0.23%, and 0.28%) supplemented with 0 or 3.5 g/kg of SO were used to create 6 diets (treatments). Each diet was fed to six replicates of 10 birds (60 birds/treatment), growth performance was measured. Caecal content samples were collected at 42 days of age. Results: Results showed that significantly different dTry level×SO interactions were found for average daily gain (ADG), caecal levels of indole, propionic acid, and butyric acid, and microbial Shannon index (p<0.05). Birds fed diet containing 0.23% dTry level with SO supplementation had higher ADG and lower feed/gain ratio than those fed the other diets (p<0.05). Broilers fed diets containing 0.28% dTry increased their caecal levels of indole and skatole compared with those containing 0.18% or 0.23% dTry (p<0.01), regardless of SO addition. SO supplementation to diets decreased the caecal skatole level by 16.17% (p<0.05), and increased the relative frequency of Clostridium IV (p<0.05), regardless of dietary dTry level. Conclusion: These results indicated that diets containing 0.23% dTry with SO supplementation positively promoted ADG, and decreased caecal skatole levels of broiler chickens. The dietary dTry level, SO affected the caecal skatole level, however, there was no interaction between them.

• Microbiology and Biotechnology Letters
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• v.50 no.3
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• pp.319-327
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• 2022

γ-Aminobutyric acid (GABA) is a multi-functional compound with broad applications for food industry. GABA producing bacteria were isolated from cabbage kimchi. Among them, B737 was the best GABA producer when culture supernatants were analyzed by TLC. B737 was identified as Levilactobacillus brevis by 16S rRNA gene sequencing. Its glutamate decarboxylase (GAD) gene was cloned by PCR and the nucleotide sequence determined. B737 GAD consisting of 485 amino acids is the largest in size among GADs reported from LAB so far. gadB from L. brevis B737 was overexpressed in Escherichia. coli BL21(DE3) using pET26b(+).pET26b(+). The recombinant GAD was purified and its size was 55 kDa by SDS-PAGE. Maximum GAD activity was observed at pH 5 and 40℃ and the activity was dependent on pyridoxal 5'-phosphate. K_m and V_max of recombinant GAD were 6.2 ± 0.06 mM and 0.34 ± 0.002 mM/min, respectively. L. brevis B737 can be used as a starter for fermented foods with high GABA contents.

• Food Science of Animal Resources
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• v.43 no.2
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• pp.245-268
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• 2023

The effects of phosphate alternatives on meat quality in marinated chicken were investigated with the application of chilling and freezing. Breast muscles were injected with solution of the green weight containing 1.5% NaCl and 2% sodium tripolyphosphate (STPP) or phosphate alternatives. Treatment variables consisted of no phosphate [control (-)], 0.3% sodium tripolyphosphate [control (+)], 0.3% prune juice (PJ), 0.3% oyster shell, 0.3% nano-oyster shell, and 0.3% yeast and lemon extract (YLE) powder. One-third of the meat samples were stored at 4℃ for 1 d, and the rest of the meats were kept at -18℃ for 7 d. In chilled meat, a lower drip loss was noted for control (+) and YLE, whereas higher cooking yield in YLE compared to all tested groups. Compared with control (+), the other treatments except PJ showed higher pH, water holding capacity, moisture content, lower thawing and cooking loss, and shear force. Natural phosphate alternatives except for PJ, improved the CIE L^* compared to control (-), and upregulated total protein solubility. However, phosphate alternatives showed similar or higher oxidative stability and impedance measurement compared to control (+), and an extensive effect on myofibrillar fragmentation index. A limited effect was observed for C^*, h°, and free amino acids in treated meat. Eventually, the texture profile attributes in cooked of phosphate alternatives improved except for PJ. The results indicate the high potential use of natural additives could be promising and effective methods for replacing synthetic phosphate in chilled and frozen chicken with quality enhancement.