• 한국수산과학회지
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• 제52권5호
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• pp.496-510
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• 2019

We investigated the reproductive characteristics of the sweetfish Plecoglossus altivelis, including changes in the gonadosomatic index (GSI), frequency of gonad developmental stages, and abundance of drifting larvae, in three streams (Gangjeong, Yeonoi, and Ongpo) on Jeju Island from May 2004 to December 2005. The GSI values of female P. altivelis in all Jeju streams began to increase in September and reached a maximum in October and November. Peak GSI values in males occurred in Gangjeong from October to November, in Yeonoi from November to January, and in Ongpo from September to October. The gonadal development of P. altivelis was classified into four stages: growth (March to October), maturity (September to December in females; July to December in males), spawning (September to January), and degeneration (October to March in females; after November in males). Drifting larvae were collected from October to January. These results suggest that the main spawning activity of P. altivelis in Jeju streams occurs from October to November. The information about the reproductive characteristics of P. altivelis obtained in this study is critical to fishery management for this species.

• 한국동물생명공학회지
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• 제36권4호
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• pp.314-322
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• 2021

Paired box protein, PAX7, is a key molecule for the specification, maintenance and skeletal muscle regeneration of muscle satellite cells. In this study, we identified and characterized the cDNA and amino acid sequences of PAX7 from black sea bream (Acanthopagrus schlegelii) via molecular cloning and sequence analysis. A. schlegelii PAX7 cDNA was comprised of 1,524 bp encoding 507 amino acids and multiple sequence alignment analysis of the translated amino acids showed that it contained three domains including paired DNA-binding domain, homeobox domain and OAR domain which were well conserved across various animal species investigated. Pairwise Sequence Alignment indicated that A. schlegelii PAX7 had the same amino acid sequences with that of yellowfin seabream (A. latus) and 99.8% identity and similarity with that of gilt-head bream (Sparus aurata). Molecular phylogenetic analysis confirmed that A. schlegelii PAX7 formed a monophyletic group with those of teleost and most closely related with those of the fish that belong to Sparidae family including A. latus and S. aurata. In the investigation of its tissue specific mRNA expression, the expression was specifically identified in skeletal muscle tissue and a weak expression was also shown in gonad tissue. The cultured cells derived from skeletal muscle tissues expressed PAX7 mRNA at early passage but the expression was not observed after several times of subculture.

• Fisheries and Aquatic Sciences
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• 제25권5호
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• pp.251-263
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• 2022

Sea cucumbers are worm-like, leathery bodied, benthic, marine organisms with a branched gonad. There are over 900 species, and these organisms are capable of changing their mechanical state, regenerating their small appendages, and digestive tract. Additionally, sea cucumbers possess both commercial and therapeutical value. Furthermore, it is thought that the metabolites these organisms possess may give rise to their therapeutical value. The use of sea cucumbers in therapy can be traced back to the Ming dynasty, where they were eaten for their tonic properties against constipation, hypertension, and rheumatism. A plethora of studies have been conducted, whereby different metabolites were extracted from sea cucumbers and tested for different therapeutic properties. Herein, we review and discuss the anti-cancer, anti-microbial, anti-coagulant, anti-diabetic, antioxidant, and anti-inflammatory properties of the sea cucumber by assessing literature on PubMed and Google Scholar. Furthermore, the genome and epigenome of these remarkable species is discussed. With the immense data supporting the therapeutic properties of sea cucumbers, further studies are warranted, in order to develop novel and innovative therapeutic compounds for the benefit of human health from these fascinating marine organisms.

• 한국수산과학회지
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• 제55권1호
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• pp.17-22
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• 2022

Successful reproduction in vertebrates necessitates complex interactions along the brain-pituitary-gonad axis, it is determined by gonadotropin releasing hormone produced in the hypothalamus of the brain, gonadotropin synthesized in the pituitary gland, and sex hormone secreted by the gonads. The goal of this study was to secure and test technology for controlling (inhibiting) sexual maturation hormones such as maturation hormones through hormone regulation. We studied the effect on sexual maturation of zebrafish Danio rerio by tamoxifen, anastrozole, exemestane and dopamine 4 kinds of sexual maturation inhibitors to feed and after administration. As a result, 4 kinds of sexual maturation inducing substances were mixed with zebrafish feed, it could be concluded that all of them were effective in inhibiting sexual maturation by reducing mRNA levels of genetic materials related to sexual maturation.

• 한국수산과학회지
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• 제57권3호
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• pp.253-261
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• 2024

This study investigated the digital color profiles corresponding to different maturity stages and levels of brown croaker Miichthys miiuy specimens collected from the Southern Sea of South Korea. Maturity stages were determined using photomicrographs of ovarian developmental phases, which were compared with digital color values. Brown croaker specimens ranged from 24 to 81 cm in standard length; mature ovaries were predominantly observed in specimens that exceed 40 cm in length. Monthly ovary color values were primarily concentrated in the 1st and 4th quadrants, with both a^* and b^* values falling within a range of ±15 centered on the origin. Similarly, the testes color values were predominantly situated in the 4th quadrant, with a^* and b^* values ranging from -5 to 15 and 10 to 14, respectively. While the color values of the mature and spawning stages overlapped within a narrow range, distinguishing between them required both the color value and monthly color value distribution to be considered. Thus, this study underscores the efficacy of digital color measurements for assessing brown croaker gonad maturity, and provides more quantitative insights compared to subjective visual assessments by humans.

• 수산해양기술연구
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• 제60권3호
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• pp.235-243
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• 2024

Researching and estimating the ecological characteristics of target fish species is crucial for fisheries resource management. The results of these estimates significantly influence stock assessments and management reference points such as size limit and closed seasons. Recently, ecological characteristics have been changing due to overfishing, climate change, and marine pollution, making continuous estimation and monitoring essential. This study analyzed the ecological changes in small yellow croaker (Larimichthys polyactis) resources in Korea over 24 years (2000-2023) using biological data (growth and gonad traits). By estimating the annual length-weight relationship and length at maturity (L50 and L95), we interpreted the numerical trends of early maturation due to resource depletion. The parameter b of the length-weight relationship, indicating the nutritional status of the resources, showed a slight increase over the years, suggesting relatively good nutritional status (b > 3.0) during most periods. Trend analysis between length at maturity and biomass indicated that as biomass decreased, maturity length also decreased.

• Clinical and Experimental Reproductive Medicine
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• 제10권2호
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• pp.25-37
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• 1983

As the cytogenetic developed, cytogenetic study has also developed progressively. This study is a systematical cytogenetic and clinico-hormonal analysis of 20 cases Wp.ere gonadal dysgenesis was diagnosed and deferred to the Dept. of obstetrics and Gynecology, Yonsei University, Medical School from Jan. 1974 to Aug. 1983. Twenty patients with the diagnosis of gonada dysgenesis have been assesed as to possible correlations between clinical, homonal and cytogenic findings. The desults were as follows; l. Gonadal dysgenesis were found in 20 cases, consisting of 15 cases (75%) of turnurs syndrome, 4 case of pure gonadal dysgenesis (20%), 46. XX and 1 case of mixed gonadal dysgenesis, 45,XO/46,XY. 2. Patients with XO karyotype, turner's ryndorme, have a resonably constant clinical picture of sexual infantilism with streak gonads, short status and webbed neck. 3. 17 cases were found primary amenorhea and two cases were noted with 2 ndary amenorrhea. one case has been presented with menstruation. 4. The rudimentary streak gonads were found in 7 cases of 8 cases and one case has a rudimentary streak gonad on one side and a testis on the contralateral side. 5. The study showed that potients with gonadal dysgenesis had an average of about 4-8 times higher basal FSH and about 3-7 times higher basal LH than that of the early follicular phase of normal menstrual cycle. 6. Two cases of three gonadal dysgenesis patieats, who performed LH-RH challage test, showed that the serum FSH levels reached the maximal level at 30 min after injection of CHRH and the serum LH level reached the maximal level at 60 min ofter injection of LHRH one case showed no significant response to LH-RH injection. Thus, bu studying simultoneously the clinical, cytogenic, hormonal aspects and visualization of gonads, we have gained some practical insight into the requirements for proper disgnosis and treatment.

• Toxicological Research
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• 제32권3호
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• pp.215-223
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• 2016

This study is to investigate the biological, biochemical and cytotoxic effects of puffer fish (Arothron stellatus) toxin extracts under in-vitro condition. Extracted toxins from various organs of puffer fish were purified by using active charcoal column, and Bio-gel-P2 column chromatography. The lethality of toxin was tested in crabs, which consists of neurotoxic compounds. The degree of the brine shrimp lethality assay was found directly proportional to the concentration of the toxin extracts, which was well supported by hemolytic assay. The experimental results suggested that the gonad was found higher toxins than the liver and muscles. The mortality rate of brine shrimp nauplii was increased with the raise of concentrations of toxin level. Among the different doses and time dependent cytotoxic effect of human cervical carcinoma (HeLa) cells were showed $4.0{\mu}g/mL$ of toxin, which was effectively inhibited cancer cell proliferation. HPLC and TLC analysis was revealed that the A. stellatus toxin contains tetrodotoxin (TTX), related compounds 4-epi TTX and anhydro-TTX. The present results suggested that the A. stellatus contain TTX as a major and anh-TTX as a minor toxin. It could be the potential candidate in the field of anticancer drug discovery against human cervical cancer cells. The present data is confirming that the puffer fish toxin as an interesting source of novel bioactive natural compounds with potent applications in pharmacology.

• Asian-Australasian Journal of Animal Sciences
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• 제7권1호
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• pp.75-81
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• 1994

To elucidate the relationship between steroidogenesis and sex differentiation in the duck, plasma, testicular and ovarian testosterone, estradiol-$17{\beta}$ and progesterone concentration in male and female embryo of day 11 to 27 (just before hatching) of incubation and in 1- to 7-day-old male and female duckling were investigated by radioimmunoassays. Plasma estradiol-$17{\beta}$ concentration in female embryos declined from very high at days 11 and 15 of incubation and remained at low levels after hatching. Male plasma estradiol-$17{\beta}$ concentration were always lower than those of the female throughout this period. Plasma testosterone and progesterone concentrations in both sexes were low during the embryonic stage, but then increased to peaks 3 days and 1 day after hatching, respectively. Estradiol-$17{\beta}$ contents were much higher in the left ovary than the right ovary or testes throughout the experimental period. The estradiol-$17{\beta}$ content of the left ovary was very high at day 15 of incubation, and decreased gradually thereafter. Both in right ovary and testes, estradiol-$17{\beta}$ contents were always low. Testosterone and progesterone contents in the left ovary were low from day 11 to 23 of incubation, and reached a peak 1 day after hatching. Progesterone content in the right ovary and testes were low levels over time period examined. Testosterone and progesterone contents were much higher in the left ovary than the right ovary and testes. The present results clearly demonstrate that the capacity of the embryonic left ovary of duck to synthesize estradiol-$17{\beta}$ and testosterone is much higher than that of the embryonic testis. It is suggested that estrogen secreted from the embryonic ovary earlier than day 15 of incubation has an important role in female sexual differentiation in the duck, and the sex of the avian species is basically male with homozygous sex chromosome (ZZ).

• 한국발생생물학회지:발생과생식
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• 제17권4호
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• pp.389-397
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• 2013

FGF9/16/20 signaling pathway specify the developmental fates of notochord, mesenchyme, and neural cells in ascidian embryos. Although a conserved Ras/MEK/Erk/Ets pathway is known to be involved in this signaling, the detailed mechanisms of regulation of FGF signaling pathway have remained largely elusive. In this study, we have isolated Hr-Erf, an ascidian orthologue of vertebrate Erf, to elucidate interactions of transcription factors involved in FGF signaling of the ascidian embryo. The Hr-Erf cDNA encompassed 3110 nucleotides including sequence encoded a predicted polypeptide of 760 amino acids. The polypeptide had the Ets DNA-binding domain in its N-terminal region. In adult animals, Hr-Erf mRNA was predominantly detected in muscle, and at lower levels in ganglion, gills, gonad, hepatopancreas, and stomach by quantitative real-time PCR (QPCR) method. During embryogenesis, Hr-Erf mRNA was detected from eggs to early developmental stage embryos, whereas the transcript levels were decreased after neurula stage. Similar to the QPCR results, maternal transcripts of Hr-Erf was detected in the fertilized eggs by whole-mount in situ hybridization. Maternal mRNA of Hr-Erf was gradually lost from the neurula stage. Zygotic expression of Hr-Erf started in most blastomeres at the 8-cell stage. At gastrula stage, Hr-Erf was specifically expressed in the precursor cells of brain and mesenchyme. When MEK inhibitor was treated, embryos resulted in loss of Hr-Erf expression in mesenchyme cells, and in excess of Hr-Erf in a-line neural cells. These results suggest that zygotic Hr-Erf products are involved in specification of mesenchyme and neural cells.