141 results match your criteria: "National Fisheries University.[Affiliation]"

The authors evaluated the adaptability of male nine-spined sticklebacks (Pungitius sinensis) at three salinity levels (0, 5 and 10 psu) by comparing nest building success rates with nest structures. Successful nest building decreased as salinity increased. In addition, nests built in fresh water (i.

View Article and Find Full Text PDF

Steroidogenesis in ovarian granulosa cells is regulated by the follicle-stimulating hormone (FSH) via transcriptional regulation of its related genes. We herein showed the involvement of the Hippo pathway in this regulation. In KGN granulosa cell, repression of YAP/TAZ activity induced the expression of CYP11A1, HSD3B2, and CYP19A1 in a TEAD-dependent manner without cAMP stimulation.

View Article and Find Full Text PDF

Although numerous reports using methods such as molecular dynamics, cellular automata, and artificial chemistry have clarified the process connecting non-life and life on protocell simulations, none of the models could simultaneously explain the emergence of cell shape, continuous self-replication, and replication control solely from molecular reactions and diffusion. Herein, we developed a model to generate all three conditions, except evolution ability, from hypothetical chains of chemical and molecular polymerization reactions. The present model considers a 2D lattice cell space, where virtual molecules are placed in each cell, and molecular reactions in each cell are based on a multiset rewriting rule, indicating stochastic transition of molecular species.

View Article and Find Full Text PDF
Article Synopsis
  • Histamine and other biogenic amines in fish cannot be removed through heating or chemical methods, necessitating alternative approaches for elimination.
  • A new method combines fungal amine oxidase (FAO) and bacterial aldehyde oxidase (ALOX) to effectively convert histamine into harmless byproducts, achieving a 100% yield of imidazole 4-acetic acid.
  • The presence of ALOX is crucial for the complete reaction, as its absence results in incomplete processing of detoxifying harmful amines.
View Article and Find Full Text PDF

The Immunomodulating Effect of Phlorotannins from a Brown Alga, Eisenia nipponica, on Mice Stimulated with Ovalbumin through T Cell Regulation.

Plant Foods Hum Nutr

June 2022

Department of Food Science and Technology, National Research and Development Agency, Japan Fisheries Research and Education Agency, National Fisheries University, Shimonoseki, Yamaguchi, Japan.

The immunomodulating effect of phlorotannin was investigated in mice stimulated by ovalbumin. When analyzing the main components of phlorotannin concentrate (PTC) from Eisenia nipponica, seven phlorotannins [eckol, 6,6'-bieckol, 6,8'-bieckol, 8,8'-bieckol, dieckol, phlorofucofuroeckol (PFF)-A, and PFF-B] were detected. These phlorotannins accounted for approximately 80% of PTC.

View Article and Find Full Text PDF
Article Synopsis
  • Local adaptation may lead to a concentrated genetic architecture, where key alleles for traits are found close together on chromosomes, as seen in the evolution of threespine stickleback fish adapting to marine versus freshwater habitats.
  • The study examined genomic rearrangements to understand how these "genomic islands" formed, using comparative analysis with the closely related tubesnout and other species.
  • Findings showed that smaller rearrangements and lineage-specific genes are more common near these adaptive loci, suggesting that selection pressures on certain genes may have led to their clustering through genomic changes.
View Article and Find Full Text PDF

Inhibition of lysozyme lytic activity by Ivy derived from Photobacterium damselae subsp. piscicida.

Fish Shellfish Immunol

May 2022

Department of Biochemistry and Applied Biosciences, Faculty of Agriculture, University of Miyazaki, Miyazaki, 889-2192, Japan. Electronic address:

Article Synopsis
  • A pseudotuberculosis pathogen, Photobacterium damselae subsp. piscicida (Pdp), is damaging yellowtail aquaculture in Japan, and the Ivy gene in its plasmid may help it evade the host's immune response.
  • Researchers studied the recombinant Ivy-Pdp protein and found it inhibits lysozyme activity, which is an immune enzyme in animals, in a concentration-dependent manner, maintaining its effectiveness under various temperatures and pH levels.
  • Ivy-Pdp was shown to significantly reduce the lytic activity of lysozyme in the serum and skin mucus of fish species like Nile tilapia, suggesting it plays a crucial role in helping Pdp evade host defenses during infection.
View Article and Find Full Text PDF

A small animal population becomes extinct owing to demographic and environmental stochasticity after declining below the minimum viable population (MVP). However, the actual process of extinction derived by stochastic factors after crossing MVP has not been recorded for long-lived marine mammals. Here, we reconstructed the declining history of a small, isolated population of dugongs in Okinawa over 125 years.

View Article and Find Full Text PDF

Living organisms such as bacteria are often exposed to continuous changes in the nutrient availability in nature. Therefore, bacteria must constantly monitor the environmental condition, and adjust the metabolism quickly adapting to the change in the growth condition. For this, bacteria must orchestrate (coordinate and integrate) the complex and dynamically changing information on the environmental condition.

View Article and Find Full Text PDF

The five β-like globin genes (ε, Gγ, Aγ, δ and β) at the human β-globin gene locus are known to be expressed at specific developmental stages, although details of the underlying mechanism remain to be uncovered. Here we used an in vitro transcription assay to clarify the mechanisms that control this gene expression. We first tested nuclear RNA from HeLa cells using RT-qPCR and discovered a long noncoding RNAs (lncRNAs) within a 5.

View Article and Find Full Text PDF

The marine raphidophyte complex forms red tides, causing heavy mortalities of aquacultured fishes in temperate coastal waters worldwide. The mechanism for fish mortality remains unresolved. Although several toxic chemicals have been proposed as responsible for fish mortality, the cause is still unclear.

View Article and Find Full Text PDF

Cholesterol-lowering effects of taurine through the reduction of ileal FXR signaling due to the alteration of ileal bile acid composition.

Amino Acids

October 2021

Department of Food Science and Technology, National Research and Development Agency, Japan Fisheries Research and Education Agency, National Fisheries University, 2-7-1, Nagata-honmachi, Shimonoseki, 759-6595, Japan.

Studies using animal models of hypercholesterolemia have established that taurine reduces cholesterol levels; however, the precise mechanism underlying this cholesterol-lowering effect is unclear. This study addressed this issue by investigating whether bile acid/farnesoid X receptor (FXR) signaling is involved in taurine-mediated cholesterol-lowering effect. Fxr-null and wild-type mice were administered 2% (w/v) taurine in their drinking water and fed a control diet or control diet supplemented with 1% (w/w) cholesterol (cholesterol diet) for 10 days.

View Article and Find Full Text PDF

The selenium (Se)-containing imidazole compound selenoneine (2-selenyl-N, N, N-trimethyl-L-histidine) is a strong scavenger of reactive oxygen species (ROS) in the blood and tissues of fish. Intravenous injection of selenoneine into yellowtail has been shown to delay changes in meat color and prevent met-myoglobin formation in red muscle. In this study, to determine whether selenoneine can improve stress tolerance and meat quality in fish, we examined the biological antioxidant functions of selenoneine in fish in vivo.

View Article and Find Full Text PDF

Local immune responses to two stages of Ichthyophthirius multifiliis in ginbuna crucian carp.

Fish Shellfish Immunol

November 2021

Laboratory of Marine Biochemistry, Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, 819-0395, Japan. Electronic address:

Ichthyophthirius multifiliis is a ciliated protozoan parasite and is known to infect many freshwater teleosts. Characterizing the immune system in epithelial tissues, where the parasites penetrate and settle, is key to understanding host-parasite interactions. This study examined local immune responses in vivo to the infective stage (theront and trophont) of the parasites using intra-fin administration, which has been developed to analyze in vivo immune responses using fish fin.

View Article and Find Full Text PDF

Many cephalopods such as octopi and squid can purposefully and rapidly change their skin color. Furthermore, it is widely known that some octopi have the ability to rapidly change the color and unevenness of their skin to mimic their surroundings. However, there has been little research published on the mechanisms by which an octopus recognizes its surrounding landscape and changes its skin pattern.

View Article and Find Full Text PDF

Marine pufferfish Takifugu exascurus is not approved for human consumption due to the lack of information on its toxicity. To clarify the toxicity of T. exascurus, ten live specimens were collected from the Sea of Kumano, Japan, and the toxicity and tetrodotoxin (TTX) concentration were determined using mouse bioassay and high performance liquid chromatography-fluorescence detection (HPLC-FLD), respectively.

View Article and Find Full Text PDF

Dieckol isolated from a brown alga, Eisenia nipponica, suppresses ear swelling from allergic inflammation in mouse.

J Food Biochem

April 2021

Laboratory of Food Function and Biochemistry, Department of Food Science and Technology, National Research and Development Agency, Japan Fisheries Research and Education Agency, National Fisheries University, Shimonoseki, Japan.

We previously found a lipophilic fraction of the methanol/chloroform extract of a brown alga, Eisenia nipponica, that had an antiallergic effect in a murine ear swelling test. In this study, we purified the active component from the lipophilic fraction using high performance liquid chromatography and analyzed the mass and nuclear magnetic resonance spectra. This uncovered the phlorotannin dieckol, which exhibited antiallergic effects in an ear swelling test using mice sensitized by arachidonic acid, 12-O-tetradecanoylphorbol-13-acetate, and oxazolone.

View Article and Find Full Text PDF

Research Background: Animal collagen has been widely utilized in foods, cosmetics and biomedical fields. The non-edible portion, such as fish skin and bones, are obtained during cooking. Most of them are currently discarded as wastes, although the nutritional value of the skin and bones is high.

View Article and Find Full Text PDF

Innate cell-mediated cytotoxicity of CD8 T cells against the protozoan parasite Ichthyophthirius multifiliis in the ginbuna crucian carp, Carassius auratus langsdorfii.

Dev Comp Immunol

February 2021

Laboratory of Marine Biochemistry, Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, 819-0395, Japan. Electronic address:

Cytotoxic T cells are known to have the ability to kill microbe-infected host cells, which makes them essential in the adaptive immunity processes of various vertebrates. In this study, we demonstrated innate cell-mediated cytotoxicity of CD8 T cells against protozoan parasites found in the ginbuna crucian carp. When isolated effector cells such as CD8, CD4 (CD4-1), or CD8 CD4 (double-negative, DN), from naïve ginbuna crucian carp were co-incubated with target parasites (Ichthyophthirius multifiliis), CD8 cells from the kidney and gill showed the highest cytotoxic activity.

View Article and Find Full Text PDF

Background: As inorganic arsenic is a highly toxic compound, its concentration in foods should be determined.

Objective: Develop an analytical method for determining inorganic arsenic in fish oil and fish oil capsules.

Method: Inorganic arsenic was extracted from fish oil by heating at 80°C in 1.

View Article and Find Full Text PDF

In animals, spermatogonial transplantation in sterile adult males is widely developed; however, despite its utility, ovarian germ cell transplantation is not well developed. We previously showed that the interspecific hybrid offspring of sciaenid was a suitable model for germ cell transplantation studies as they have germ cell-less gonads. However, all these gonads have testis-like characteristics.

View Article and Find Full Text PDF

Speciation is a continuous process. Although it is known that differential adaptation can initiate divergence even in the face of gene flow, we know relatively little about the mechanisms driving complete reproductive isolation and the genomic patterns of divergence and introgression at the later stages of speciation. Sticklebacks contain many pairs of sympatric species differing in levels of reproductive isolation and divergence history.

View Article and Find Full Text PDF

Co-Occurrence of Tetrodotoxin and Saxitoxins and Their Intra-Body Distribution in the Pufferfish .

Toxins (Basel)

July 2020

Graduate School of Fisheries and Environmental Sciences, Nagasaki University. 1-14, Bunkyo-machi, Nagasaki, Nagasaki 852-8521, Japan.

Pufferfish of the family Tetraodontidae possess tetrodotoxin (TTX) and/or saxitoxins (STXs), but the toxin ratio differs, depending on the genus or species. In the present study, to clarify the distribution profile of TTX and STXs in Tetraodontidae, we investigated the composition and intra-body distribution of the toxins in . specimens (four male and six female) were collected from Amami-Oshima Island, Kagoshima Prefecture, Japan, and the toxins were extracted from the muscle, liver, intestine, gallbladder, gonads, and skin.

View Article and Find Full Text PDF

Selenoneine Ameliorates Hepatocellular Injury and Hepatic Steatosis in a Mouse Model of NAFLD.

Nutrients

June 2020

Department of Food Science and Technology, National Research and Development Agency, Japan Fisheries Research and Education Agency, National Fisheries University, 2-7-1, Nagata-Honmachi, Shimonoseki 759-6595, Japan.

Selenoneine is a novel organic selenium compound markedly found in the blood, muscles, and other tissues of fish. This study aimed to determine whether selenoneine attenuates hepatocellular injury and hepatic steatosis in a mouse model of non-alcoholic fatty liver disease (NAFLD). Mice lacking farnesoid X receptor (FXR) were used as a model for fatty liver disease, because they exhibited hepatomegaly, hepatic steatosis, and hepatic inflammation.

View Article and Find Full Text PDF