Comp Biochem Physiol A Mol Integr Physiol
October 2025
Fish inhabiting diverse photic environments, from the deep sea to shallow freshwater, offer a valuable model for studying visual receptor characteristics and spectral adaptation mechanisms. This study investigated changes in visual opsin transcript levels in Japanese eels (Anguilla japonica) during sexual development and exposure to light conditions simulating their life cycle. Tissue-specific expression analysis revealed the predominance of four opsin genes (dso, fwo, rh2, and sws2) in the eyes.
View Article and Find Full Text PDFChickens are one of the most economically and nutritionally important livestock species globally, yet they are highly vulnerable to environmental stressors which compromise their growth and physiological stability. In this study we investigated the effect of wind speed on growth performance, physiological responses, blood profiles, and transcriptomic adaptations in Ross-308 broilers under high-temperature conditions. A total of 240 broilers were divided into three groups: low wind, high temperature (LWH; 33°C, 60% RH, 0 m/s), medium wind, high temperature (MWH; 33°C, 60% RH, 1 m/s), and high wind, high temperature (HWH; 33°C, 60% RH, 2 m/s).
View Article and Find Full Text PDFLead (Pb) is a non-essential toxic metal that accumulates in aquatic environments, negatively impacting fish health. This study evaluated the acute toxicity of Pb in starry flounders (). Fish (41 ± 8.
View Article and Find Full Text PDFJ Exp Zool A Ecol Integr Physiol
January 2025
Assessment of the clock genes, Period (Per) 1, Per2, Per3, and Cryptochrome (Cry) 2, Cry3, and Cry4, can help better understand eel spawning ecology. In this study, the circadian rhythm and moonlight effects of these clock genes in the eel retina and hypothalamus were analyzed. We examined clock gene expression patterns under 12 h light:12 h darkness (12L12D), constant darkness (DD), and constant light (LL) conditions; under short photoperiod (SP; 9L15D) and long photoperiod (LP; 15L9D), and during the new moon (NM) and full moon in male eels.
View Article and Find Full Text PDFWe produced a recombinant eel luteinizing hormone (rec-eel LH) analog with high potency in Chinese hamster ovary DG44 (CHO DG44) cells. The tethered eel LH mutant (LH-M), which had a linker comprising the equine chorionic gonadotropin (eLH/CG) β-subunit carboxyl-terminal peptide (CTP) region (amino acids 115 to 149), was inserted between the β-subunit and α-subunit of wild-type tethered eel LH (LH-wt). Monoclonal cells transfected with the tethered eel LH-wt and eel LH-M plasmids were isolated from five to nine clones of CHO DG44 cells, respectively.
View Article and Find Full Text PDFJ Exp Zool A Ecol Integr Physiol
May 2024
Japanese eel (Anguilla japonica) is a commercially important fish species in Asia. Understanding factors like photoperiod, temperature, and lunar cycles is crucial for successful aquaculture and managing its reproduction. Melatonin and dopamine (DA) are essential for regulating reproduction in vertebrates, including fish.
View Article and Find Full Text PDFInt J Mol Sci
January 2023
Pinostrobin is a dietary flavonoid found in several plants that possesses pharmacological properties, such as anti-cancer, anti-virus, antioxidant, anti-ulcer, and anti-aromatase effects. However, it is unclear if pinostrobin exerts anti-melanogenic properties and, if so, what the underlying molecular mechanisms comprise. Therefore, we, in this study, investigated whether pinostrobin inhibits melanin biosynthesis in vitro and in vivo, as well as the potential associated mechanism.
View Article and Find Full Text PDFPolymethoxyflavones (PMFs) are flavonoids exclusively found in certain citrus fruits and have been reported to be beneficial to human health. Most studies have been conducted with PMFs isolated from citrus peels, while there is no study on PMFs isolated from leaves. In this study, we prepared a PMF-rich fraction (PRF) from the leaves of Hort ex.
View Article and Find Full Text PDFPhotoperiod plays a role in controlling the initiation and termination of reproduction in fish. Melatonin is an internal transducer of environmental photoperiod and is involved in regulating reproduction. The present study aimed to examine how melatonin impacts the transcript levels of kisspeptin (kiss1 and kiss2), gonadotropin-releasing hormones (gnrh1), and the β-subunit of gonadotropins (fshβ and lhβ) in the brain of the sapphire devil, a tropical damselfish with long photoperiod preference.
View Article and Find Full Text PDFAnim Cells Syst (Seoul)
November 2021
has been reported to possess beneficial properties for human health, but its effects on metabolic syndrome have not been reported. In this study, we investigated the effect of leaf extract (CT) on the metabolic derangements induced by a high-fructose (HF) diet. Sprague-Dawley rats were fed with a 46% carbohydrate diet (HC group), 60% high-fructose diet (HF group), or HF diet supplemented with CT (500 mg/kg of body weight/day, CT group) via drinking water for 16 weeks.
View Article and Find Full Text PDFTo date, 19 species of spiny lobsters from the genus have been discovered, of which only , , , and have been documented in South Korean waters. In this study, we aimed to identify and update the current list of spiny lobster species that inhabit South Korean waters based on the morphological features and the phylogenetic profile of cytochrome oxidase I (COI) of mitochondrial DNA (mtDNA). Spiny lobsters were collected from the southern and eastern coasts of Jeju Island, South Korea.
View Article and Find Full Text PDFObjective: According to reported spawning characteristics of Japanese eel, , which exhibit spawning and migration patterns that are synchronized with lunar cycles and photoperiod, we hypothesized that a close association exists between specific photic signals (daylight, daylength, and moonlight) and endocrinological regulation. Given the photic control in melatonin secretion, this hypothesis was tested by investigating whether melatonin signals act as mediators relaying photic signals during testis development in the eel.
Methods: We examined changes in melatonin-secretion patterns using time-resolved fluorescence immunoassays in sexually immature and mature male Japanese eels under the condition of a new moon (NM) and a full moon (FM).
Background: Increased dietary fructose consumption is closely associated with lipid and glucose metabolic disorders. Nakai possesses various health-promoting properties, but there has been no research on its protective effect against fructose-induced metabolic dysfunction. In this study, we investigated the effects of leaf extract (SQE) on metabolic dysfunction in high-fructose-diet-fed rats.
View Article and Find Full Text PDFis a folk medicine exhibiting anti-hypertension, anti-arthritis, and anti-rheumatism properties. However, little is known about whether the material might prevent hyperuricemia and associated inflammation. In this study, we explored whether leaf extract (CTE) prevented hyperuricemia induced by potassium oxonate (PO) in mice.
View Article and Find Full Text PDFFish that inhabit shallow water are exposed to periodic changes in tidal cues, including hydrostatic pressure (HP). The present study aimed at verifying differentially expressed genes (DEGs) in the brain of the threespot wrasse Halichoeres trimaculatus (tropical species) and the honbera wrasse Halichoeres tenuispinis (temperate species), both of which were exposed to HP at 30 kPa (possible high-tide stimuli in the field) or 1 kPa (low tide) for 3 or 6 h. A de novo assembly yielded 174,710 contigs (63,530 contigs were annotated) from the brain of threespot wrasse.
View Article and Find Full Text PDFThis study was carried out to identify and estimate physiological function of a new type of opsin subfamily present in the retina and whole brain tissues of Japanese eel using RNA-Seq transcriptome method. A total of 18 opsin subfamilies were identified through RNA-seq. The visual opsin family included Rh2, SWS2, FWO, DSO, and Exo-Rhod.
View Article and Find Full Text PDFThe aim of this study was to investigate the expression patterns of ocular melatonin in the annual reproductive cycle of the female grass puffer. Spawning season of the female grass puffer is from June to July in Jeju, South Korea. Time-resolved fluoroimmunoassay revealed that levels of ocular melatonin, which show an annual change, peaked in May (spawning season).
View Article and Find Full Text PDFThe sapphire devil (Chrysiptera cyanea) is a tropical damselfish that undergoes active reproduction under long-day conditions. To elucidate the physiological regulation of the brain-pituitary-gonadal axis in female sapphire devil, we cloned and characterized the genes of two kisspeptins (kiss1 and kiss2), three gonadotropin-releasing hormones (gnrh1, gnrh2, gnrh3), and the β-subunit of two gonadotropins (fshβ and lhβ) and investigated the gene expression changes during ovarian development. Quantitative polymerase chain reaction analyses in various brain parts revealed high expression levels of kiss1, kiss2, and gnrh2 in the diencephalon; gnrh2 and gnrh3 in the telencephalon; and fshβ and lhβ in the pituitary.
View Article and Find Full Text PDFComp Biochem Physiol A Mol Integr Physiol
February 2020
Dopamine plays a crucial role in controlling reproduction in eels, and its action is mediated through D2-type dopamine receptors. D2A and D2B receptors in the Japanese eel Anguilla japonica were cloned and characterized in the present study. Attention (daily expression patterns in the brain and endogenous regulation) was paid to D2B receptor because it is considered to play a crucial role in eel reproduction.
View Article and Find Full Text PDFThyroid hormone (TH) is involved in regulating the reproduction of vertebrates. Its physiological action in the target tissues is due to the conversion of TH by iodothyronine deiodinases. In this study, we aimed to clone and characterize type 2 (sdDio2) and type 3 (sdDio3) of the sapphire devil Chrysiptera cyanea, a tropical damselfish that undergoes active reproduction under long-day conditions, and to study the involvement of THs in the ovarian development of this species.
View Article and Find Full Text PDFDuring the long migration from river habitats to the spawning ground, the Japanese eel undergoes sexual maturation. This spawning migration occurs concurrently with morphological changes, such as increases in eye size; however, the mechanisms by which sex steroids and their receptors influence these changes in peripheral tissues remain unclear. The aim of this study was to investigate changes in the eyes of female Japanese eels during sexual maturation, and our research focused on estrogen receptor (ER)α and ERβ transcripts.
View Article and Find Full Text PDFGenes Genomics
March 2019
Introduction: It has been reported that various plant species may enhance the elimination of fatigue-related metabolites. However, relatively few studies have directly addressed the potential anti-fatigue effects.
Objective: The objective of this study was to investigate the anti-fatigue potential of a hot water extract of Sasa quelpaertensis Nakai leaf (SQH) in male ICR mice.
In order to examine the effects of four different light spectra (white, red, green, and blue) on the oocyte maturation, the change of reproductive parameters, via brain-pituitary-gonad (BPG) axis in grass puffer, were investigated. After exposure four different light spectra for 7 weeks, the abundance of gonadotropin-releasing hormone () mRNA which is a type of seabream () and two different subunit of gonadotropin hormones mRNAs, follicle-stimulating hormone () mRNA and luteinizing hormone () mRNA, were analyzed in the brain and pituitary. Histological analysis showed that the mature oocyte ratio in the green spectrum was higher than other light spectra-exposed groups.
View Article and Find Full Text PDFMost wrasses are protogynous species that swim to feed, reproduce during the daytime, and bury themselves under the sandy bottom at night. In temperate and subtropical wrasses, low temperature influences emergence from the sandy bottom in the morning, and induces a hibernation-like state in winter. We cloned and characterized the prohormone complementary DNAs (cDNAs) of arginine vasotocin (AVT) and isotocin (IT) in a temperate wrasse (Halichoeres tenuispinis) and examined the effects of day/night and temperature on their expression in the diencephalon, because these neurohypophysial peptides are related to the sex behavior of wrasses.
View Article and Find Full Text PDFMost wrasse species swim during the day and bury themselves in the sandy bottoms of shallow reefs at night. This study aimed to evaluate the importance of sandy bottoms to the day-active/night-inactive rhythmicity of the tropical wrasse Halichoeres trimaculatus. Actogram analysis revealed that fish were active during the photophase and inactive during the scotophase in aquariums with both sandy and bare bottoms.
View Article and Find Full Text PDF