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Wang T, Wu L, Chen Q, Chen K, Tan F, Liu J, Liu X, Han H. Copper deposition in Wilson's disease causes male fertility decline by impairing reproductive hormone release through inducing apoptosis and inhibiting ERK signal in hypothalamic-pituitary of mice. Front Endocrinol (Lausanne) 2022; 13:961748. [PMID: 35992126 PMCID: PMC9389053 DOI: 10.3389/fendo.2022.961748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Accepted: 07/11/2022] [Indexed: 11/13/2022] Open
Abstract
Wilson's disease (WD) is an autosomal recessive disorder of copper metabolism characterized by liver and central nervous system dysfunction. Considerable evidence suggests that infertility is also very common in male patients with WD, but the exact molecular mechanisms involved remain unknown. In order to further investigate the pathological changes in the hypothalamic-pituitary-testicular (HPT) axis and its mechanisms, mice were divided into the normal control group (NC), WD model TX mice group (WD), dimercaptosuccinic acid-treated TX mice group (DMSA), and pregnant horse serum gonadotropin-treated TX mice group (PMSG). The copper content and morphology of hypothalamus and pituitary tissues, the ultrastructure and apoptosis of hypothalamus neurons and pituitary gonadotropin cells, the serum levels of reproductive hormones, and the pregnancy rate and litter size of the female mice were studied. The expression of apoptosis-related proteins and the phosphorylation of extracellular regulatory protein kinase (ERK) 1/2 in the hypothalamus and pituitary were detected. The results showed that the copper content was significantly increased in the WD group, and the histopathological morphology and ultrastructure of the hypothalamus and pituitary were damaged. The levels of the gonadotropin-releasing hormone, the follicle-stimulating hormone, the luteinizing hormone, and testosterone were significantly decreased. The apoptosis rate in the hypothalamus and pituitary was significantly increased. The expressions of proapoptotic proteins Bax and Caspase-3 were significantly increased, the expression of the anti-apoptotic protein Bcl-2 was significantly decreased, and the phosphorylation level of ERK1/2 was significantly decreased. Fertility is significantly reduced. After DMSA intervention, the hypothalamus tissue copper content decreased, the hypothalamus and pituitary tissue morphology and ultrastructure were improved, cell apoptosis was alleviated, the expression of Bax and Caspase-3 was significantly decreased, the expression of Bcl-2 was significantly increased, and the reproductive hormone level, phosphorylation level, and fertility were increased. Fertility was preserved after treatment with PMSG in male TX mice. These results suggest that copper deposition in WD causes male fertility decline by impairing reproductive neuroendocrine hormone release through inducing apoptosis and inhibiting the ERK signal in the hypothalamic-pituitary region. This study can also provide reference for the damage of copper pollution to the male reproductive system.
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Affiliation(s)
- Tingting Wang
- Encephalopathy Center, The First Affiliated Hospital, Anhui University of Traditional Chinese Medicine, Hefei, China
| | - Limin Wu
- Reproductive and Genetic Branch, The First Affiliated Hospital of University of Science and Technology of China (USTC), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
- *Correspondence: Hui Han, ; Limin Wu,
| | - Qiuying Chen
- Encephalopathy Center, The First Affiliated Hospital, Anhui University of Traditional Chinese Medicine, Hefei, China
| | - Kuiyu Chen
- Encephalopathy Center, The First Affiliated Hospital, Anhui University of Traditional Chinese Medicine, Hefei, China
| | - Fang Tan
- Encephalopathy Center, The First Affiliated Hospital, Anhui University of Traditional Chinese Medicine, Hefei, China
| | - Jiabo Liu
- Encephalopathy Center, The First Affiliated Hospital, Anhui University of Traditional Chinese Medicine, Hefei, China
| | - Xiang Liu
- Encephalopathy Center, The First Affiliated Hospital, Anhui University of Traditional Chinese Medicine, Hefei, China
| | - Hui Han
- Encephalopathy Center, The First Affiliated Hospital, Anhui University of Traditional Chinese Medicine, Hefei, China
- *Correspondence: Hui Han, ; Limin Wu,
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Lin G, Gao D, Lu J, Sun X. Transcriptome Profiling Reveals the Sexual Dimorphism of Gene Expression Patterns during Gonad Differentiation in the Half-Smooth Tongue Sole (Cynoglossus semilaevis). MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2021; 23:18-30. [PMID: 32996005 DOI: 10.1007/s10126-020-09996-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 09/10/2020] [Indexed: 06/11/2023]
Abstract
The half-smooth tongue sole (Cynoglossus semilaevis), one of the most economically-important fish species in China, exhibits sexually dimorphic growth. An understanding of sex-related gene expression patterns in the tongue sole may inform sex regulation and breeding processes that increase fish production. However, the gene expression patterns during gonad development in the tongue sole remain unknown. In this study, transcriptome sequencing analyses were performed during gonad differentiation in the tongue sole, namely, at 62 days post-hatching (dph), 100 dph, 120 dph, and 150 dph. Differentially expressed genes associated with sex differentiation and gonad development were identified at each time point. Trend analysis showed that gene expression patterns varied over time. These expression patterns either explained common, non-sexually-dimorphic features or indicated significant sexual dimorphism. Transcript structure analyses identified both sex and time differences among samples. This study investigated the time-dependent expression patterns of several sex-related genes, including Dmrt1, Amh, Foxl2, aromatase encoding gene, Esr, and the Sox gene family, during gonad differentiation in the tongue sole. These results might clarify the significant sexual differences during early development in the tongue sole and might provide insight into the mechanisms controlling sex differentiation and development.
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Affiliation(s)
- Genmei Lin
- School of Marine Sciences, Sun Yat-sen University, Zhuhai, China
| | - Dong Gao
- School of Marine Sciences, Sun Yat-sen University, Zhuhai, China
| | - Jianguo Lu
- School of Marine Sciences, Sun Yat-sen University, Zhuhai, China.
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China.
| | - Xiaowen Sun
- Heilongjiang River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Harbin, China
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Zahangir MM, Matsubara H, Ogiso S, Suzuki N, Ueda H, Ando H. Expression dynamics of the genes for the hypothalamo-pituitary-gonadal axis in tiger puffer (Takifugu rubripes) at different reproductive stages. Gen Comp Endocrinol 2021; 301:113660. [PMID: 33189658 DOI: 10.1016/j.ygcen.2020.113660] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 11/05/2020] [Accepted: 11/07/2020] [Indexed: 12/27/2022]
Abstract
Tiger puffer, Takifugu rubripes, a commercially important long-distance migratory fish, return to specific spawning grounds for reproduction. To clarify reproductive neuroendocrine system of the tiger puffer, the changes in the expression levels of the genes encoding three gonadotropin-releasing hormones (GnRHs), gonadotropin-inhibitory hormone (GnIH), GnIH receptor (GnIH-R), kisspeptin and kisspeptin receptor in the brain and gonadotropin (GTH) subunits, growth hormone (GH) and prolactin (PRL) in the pituitary were examined in the tiger puffer captured in the wild at different reproductive stages, namely immature and mature fish of both sexes, and post-ovulatory females that were obtained by hormonal treatment. The amounts of three gnrh mRNAs, gnih, gnih-r, fshb and lhb were substantially increased in the mature fish compared to the immature fish, especially in the females, and these augmented expressions were drastically decreased in the post-ovulatory females. gh expression showed a slight increase in the mature males. In contrast, kiss2, kiss2r and prl did not show significant changes in the males but significantly decreased in the post-ovulatory females. The present results demonstrate the expression dynamics of the hypothalamo-pituitary-gonadal axis genes associated with the reproductive conditions and the possible involvement of the GnRH/GnIH/GTH system in the regulation of the sexual maturation and spawning in the wild tiger puffer.
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Affiliation(s)
- Md Mahiuddin Zahangir
- Marine Biological Station, Sado Island Center for Ecological Sustainability, Niigata University, Sado, Niigata 952-2135, Japan
| | - Hajime Matsubara
- Noto Center for Fisheries Science and Technology, Kanazawa University, Noto-cho, Ishikawa 927-0552, Japan
| | - Shouzo Ogiso
- Noto Marine Laboratory, Institute of Nature and Environmental Technology, Kanazawa University, Noto-cho, Ishikawa 927-0553, Japan
| | - Nobuo Suzuki
- Noto Marine Laboratory, Institute of Nature and Environmental Technology, Kanazawa University, Noto-cho, Ishikawa 927-0553, Japan
| | - Hiroshi Ueda
- Hokkaido University and Hokkaido Aquaculture Promotion Corporation, Sapporo 003-0874, Japan
| | - Hironori Ando
- Marine Biological Station, Sado Island Center for Ecological Sustainability, Niigata University, Sado, Niigata 952-2135, Japan.
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Muñoz-Cueto JA, Zmora N, Paullada-Salmerón JA, Marvel M, Mañanos E, Zohar Y. The gonadotropin-releasing hormones: Lessons from fish. Gen Comp Endocrinol 2020; 291:113422. [PMID: 32032603 DOI: 10.1016/j.ygcen.2020.113422] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 02/02/2020] [Accepted: 02/03/2020] [Indexed: 12/26/2022]
Abstract
Fish have been of paramount importance to our understanding of vertebrate comparative neuroendocrinology and the mechanisms underlying the physiology and evolution of gonadotropin-releasing hormones (GnRH) and their genes. This review integrates past and recent knowledge on the Gnrh system in the fish model. Multiple Gnrh isoforms (two or three forms) are present in all teleosts, as well as multiple Gnrh receptors (up to five types), which differ in neuroanatomical localization, pattern of projections, ontogeny and functions. The role of the different Gnrh forms in reproduction seems to also differ in teleost models possessing two versus three Gnrh forms, Gnrh3 being the main hypophysiotropic hormone in the former and Gnrh1 in the latter. Functions of the non-hypothalamic Gnrh isoforms are still unclear, although under suboptimal physiological conditions (e.g. fasting), Gnrh2 may increase in the pituitary to ensure the integrity of reproduction under these conditions. Recent developments in transgenesis and mutagenesis in fish models have permitted the generation of fish lines expressing fluorophores in Gnrh neurons and to elucidate the dynamics of the elaborate innervations of the different neuronal populations, thus enabling a more accurate delineation of their reproductive roles and regulations. Moreover, in combination with neuronal electrophysiology, these lines have clarified the Gnrh mode of actions in modulating Lh and Fsh activities. While loss of function and genome editing studies had the premise to elucidate the exact roles of the multiple Gnrhs in reproduction and other processes, they have instead evoked an ongoing debate about these roles and opened new avenues of research that will no doubt lead to new discoveries regarding the not-yet-fully-understood Gnrh system.
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Affiliation(s)
- José A Muñoz-Cueto
- Department of Biology, Faculty of Marine and Environmental Sciences and INMAR, University of Cádiz, CEIMAR, The European University of the Seas (SEA-EU), Puerto Real (Cádiz), Spain.
| | - Nilli Zmora
- Department of Marine Biotechnology, Institute of Marine and Environmental Technology, University of Maryland Baltimore County, Baltimore, MD, USA
| | - José A Paullada-Salmerón
- Department of Biology, Faculty of Marine and Environmental Sciences and INMAR, University of Cádiz, CEIMAR, The European University of the Seas (SEA-EU), Puerto Real (Cádiz), Spain
| | - Miranda Marvel
- Department of Marine Biotechnology, Institute of Marine and Environmental Technology, University of Maryland Baltimore County, Baltimore, MD, USA
| | - Evaristo Mañanos
- Institute of Aquaculture of Torre de la Sal, CSIC, Castellón, Spain
| | - Yonathan Zohar
- Department of Marine Biotechnology, Institute of Marine and Environmental Technology, University of Maryland Baltimore County, Baltimore, MD, USA.
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Ghoshal A, Daniel DK, Bhat A. Temporal patterns and sex differences in dyadic interactions in a wild zebrafish population. Behav Processes 2019; 166:103896. [DOI: 10.1016/j.beproc.2019.103896] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 06/24/2019] [Accepted: 06/28/2019] [Indexed: 01/24/2023]
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Yang Y, Shu L, Jiang Q, Huang H, Ye H. Does the bone morphogenetic protein 7 inhibit oocyte maturation by autocrine/paracrine in mud crab? Gen Comp Endocrinol 2018; 266:119-125. [PMID: 29746856 DOI: 10.1016/j.ygcen.2018.05.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 04/12/2018] [Accepted: 05/06/2018] [Indexed: 12/16/2022]
Abstract
A bone morphogenetic protein ligand (BMP7) and its two receptors (BMPRIB and BMPRII) were recently cloned and characterized in the mud crab, Scylla paramamosain. However specific functions of BMP7 and the mechanistic pathways regulating its function are largely unidentified. In the present study, we separated oocytes and follicle cells from the ovarian explants of S. paramamosain. Subsequent analysis using semi-quantitative PCR demonstrated that the mRNA of Sp-BMP7 was exclusively expressed in follicle cells while Sp-BMPRs were expressed in both oocytes and follicle cells. In vitro experiments further showed that the mRNA and protein levels of Cyclin B increased but Sp-BMP7 declined in 17α, 20β-Dihydroxyprogesterone (DHP)-induced oocytes. Furthermore, the inhibitory effects of Sp-BMP7 were not affected by the elimination of the contact/gap junction-mediated communication between oocytes and follicle cells. Our data indicate that BMP7 may play a role in the suppression of DHP-induced oocyte maturation by affecting autocrine/paracrine pathways in S. paramamosain.
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Affiliation(s)
- Ya'nan Yang
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Ling Shu
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Qingling Jiang
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Huiyang Huang
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, China.
| | - Haihui Ye
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, China; Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Xiamen, China.
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Zmora N, Wong TT, Stubblefield J, Levavi-Sivan B, Zohar Y. Neurokinin B regulates reproduction via inhibition of kisspeptin in a teleost, the striped bass. J Endocrinol 2017; 233:159-174. [PMID: 28330973 DOI: 10.1530/joe-16-0575] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Accepted: 02/20/2017] [Indexed: 12/14/2022]
Abstract
Kisspeptin and neurokinin B (NKB) are neuropeptides co-expressed in the mammalian hypothalamus and coordinately control GnRH signaling. We have found that Nkb and kisspeptin neurons are distinct in the teleost, striped bass (STB) and capitalized on this phenomenon to study the mode of action of Nkb and its related neuropeptide-F (Nkf), both of which are encoded by the tac3 gene. In vitro brain slices and in vivo administration studies revealed that Nkb/f consistently downregulated kiss2, whereas antagonist (AntD) administration restored this effect. Overall, a minor effect was noted on gnrh1 expression, whereas Gnrh1 content in the pituitaries was reduced after Nkb/f treatment and increased with AntD. Concomitantly, immunostaining demonstrated that hypothalamic Nkb neurons border and densely innervate the largest kiss2 neuronal population in the hypothalamus, which also coexpresses Nkb receptor. No expression of Nkb receptor or Nkb neuronal projections was detected near/in Gnrh1 soma in the preoptic area. At the level of the pituitary, however, the picture was more complex: both Nkb/f and AntD upregulated lhb and fshb expression and Lh secretion in vivo Together with the stimulatory effect of Nkb/f on Lh/Fsh secretion from pituitary cells, in vitro, this may indicate an additional independent action of Nkb/f within the pituitary, in which the hypothalamic pathway is more dominant. The current study demonstrates that Nkb/f utilizes multiple pathways to regulate reproduction in the STB and that in the brain, Nkb mainly acts as a negative modulator of kiss2 to regulate the release of Gnrh1.
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Affiliation(s)
- Nilli Zmora
- Department of Marine BiotechnologyInstitute of Marine and Environmental Technology, University of Maryland Baltimore County, Baltimore, Maryland, USA
| | - Ten-Tsao Wong
- Department of Marine BiotechnologyInstitute of Marine and Environmental Technology, University of Maryland Baltimore County, Baltimore, Maryland, USA
| | - John Stubblefield
- Department of Marine BiotechnologyInstitute of Marine and Environmental Technology, University of Maryland Baltimore County, Baltimore, Maryland, USA
| | - Berta Levavi-Sivan
- Department of Animal SciencesFaculty of Agriculture, Food and Environment, The Hebrew University, Rehobot, Israel
| | - Yonathan Zohar
- Department of Marine BiotechnologyInstitute of Marine and Environmental Technology, University of Maryland Baltimore County, Baltimore, Maryland, USA
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Zhang LH, Luo Z, Song YF, Shi X, Pan YX, Fan YF, Xu YH. Effects and mechanisms of waterborne copper exposure influencing ovary development and related hormones secretion in yellow catfish Pelteobagrus fulvidraco. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2016; 178:88-98. [PMID: 27472784 DOI: 10.1016/j.aquatox.2016.07.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 07/19/2016] [Accepted: 07/21/2016] [Indexed: 06/06/2023]
Abstract
The present study was conducted to determine the effects and mechanism of waterborne copper (Cu) exposure influencing ovary development and related hormones secretion in yellow catfish Pelteobagrus fulvidraco. To this end, two experiments were conducted. In Exp. 1, the partial cDNA sequences of three steroidogenesis-related genes (androgen receptor (ar), steroidogenic factor 1 (sf-1) and steroidogenic acute regulatory protein (star)) were firstly characterized from P. fulvidraco. The predicted amino acid sequences for the P. fulvidraco ar, sf-1 and star contained the main structural features characteristic in other species. In Exp. 2, P. fulvidraco were exposed to three waterborne Cu concentrations (control, 30μg/l and 60μg/l, respectively) for 56days. Sampling occurred on day 28 and day 56, respectively. On day 28, the levels of serum sex-steroid hormones (FSH and LH) and the mRNA levels of steroidogenesis-related genes (3β-hsd, cyp11a1, cyp17, cyp19a, sf-1 and star) were significantly increased in ovary of P. fulvidraco exposed to 30μg Cu/l. The immunohistochemical analysis showed the positive reaction of ER, VTG and aromatase in low dose exposure group. These indicated that in low dose and relative short-term exposure, Cu was beneficial. In contrast, 60μg Cu/l exposure significantly reduced the levels of serum FSH, LH, E2 and P, and the mRNA levels of ovarian 20β-hsd, cyp19a and erα in P. fulvidraco. On day 56, waterborne Cu concentration exposure reduced the levels of serum gonadotropins and sex hormones, and down-regulated the mRNA levels of steroidogenesis-related genes, indicating long-term Cu exposure had toxic effect on the secretion of sex-steroid hormone in P. fulvidraco. For the first time, our study cloned cDNA sequences of ar, sf-1 and star in P. fulvidraco, and demonstrated the effects and mechanism of waterborne Cu exposure influencing hormones secretion and synthesis in dose- and time-dependent manner in P. fulvidraco, which will help to understand the Cu-induced reproductive toxicity at both protein and transcriptional levels in fish.
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Affiliation(s)
- Li-Han Zhang
- Laboratory of Nutrition and Feed for Aquatic Economic Animals, Fishery College, Huazhong Agricultural University, Wuhan 430070, China; Freshwater Aquaculture Collaborative Innovative Center of Hubei Province, Wuhan 430070, China
| | - Zhi Luo
- Laboratory of Nutrition and Feed for Aquatic Economic Animals, Fishery College, Huazhong Agricultural University, Wuhan 430070, China; Freshwater Aquaculture Collaborative Innovative Center of Hubei Province, Wuhan 430070, China; Hubei Provincial Engineering Laboratory for Pond Aquaculture, Wuhan 430070, China.
| | - Yu-Feng Song
- Laboratory of Nutrition and Feed for Aquatic Economic Animals, Fishery College, Huazhong Agricultural University, Wuhan 430070, China; Freshwater Aquaculture Collaborative Innovative Center of Hubei Province, Wuhan 430070, China
| | - Xi Shi
- Laboratory of Nutrition and Feed for Aquatic Economic Animals, Fishery College, Huazhong Agricultural University, Wuhan 430070, China; Freshwater Aquaculture Collaborative Innovative Center of Hubei Province, Wuhan 430070, China
| | - Ya-Xiong Pan
- Laboratory of Nutrition and Feed for Aquatic Economic Animals, Fishery College, Huazhong Agricultural University, Wuhan 430070, China; Freshwater Aquaculture Collaborative Innovative Center of Hubei Province, Wuhan 430070, China
| | - Yao-Fang Fan
- Laboratory of Nutrition and Feed for Aquatic Economic Animals, Fishery College, Huazhong Agricultural University, Wuhan 430070, China; Freshwater Aquaculture Collaborative Innovative Center of Hubei Province, Wuhan 430070, China
| | - Yi-Huan Xu
- Laboratory of Nutrition and Feed for Aquatic Economic Animals, Fishery College, Huazhong Agricultural University, Wuhan 430070, China; Freshwater Aquaculture Collaborative Innovative Center of Hubei Province, Wuhan 430070, China
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Elisio M, Chalde T, Miranda LA. Seasonal changes and endocrine regulation of pejerrey (Odontesthes bonariensis) spermatogenesis in the wild. Gen Comp Endocrinol 2015; 221:236-43. [PMID: 25623146 DOI: 10.1016/j.ygcen.2015.01.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 01/12/2015] [Accepted: 01/14/2015] [Indexed: 02/05/2023]
Abstract
The endocrine mechanisms that regulate spermatogenesis and their interaction with environmental cues have been poorly studied compared with oogenesis in fish. The aim of this work was to study the spermatogenesis in pejerrey under the influence of photoperiod and water temperature fluctuation in the wild, evaluating the transcript levels of brain Gnrh variants and cyp19a1b, pituitary Gth subunits, gonadal Gth receptors, 11β-hsd, and 11-KT plasma levels. Males at spermiogenic stage were observed during spring and autumn, under a photoperiod above 11h of light and a water temperature below 23 °C. Most arrested males were observed in summer when water temperatures increased above 23 °C. Males at spermatogonial stage were mainly observed in autumn, while most males at spermatocytary stage were caught in winter. An increase of gnrh-I, cyp19a1b, fshb, gpha and 11β-hsd transcripts and 11-KT plasma levels was observed during spermatogonial and/or spermatocytary stage (early spermatogenesis). The spermiogenic stage was associated to the maximum gnrh-I gene expression level and a significant increase of Gth receptors transcripts, being this fact more evident for lhcgr. During this last gonadal stage, cyp19a1b transcript level remained high, while fshb mRNA and 11-KT plasma levels showed a significant decreased compared to that occurred at the spermatocytary stage. Also, gphα and 11β-hsd gene expression levels fell during spermiation up to similar values to those observed in arrested males. A significant correlation between 11-KT and gnrh-I, cyp19a1b, gphα, fshb, 11β-hsd transcripts, and the number of spermatocytes was observed during spermatogenesis. All these findings suggested that in pejerrey, the spermatocyte proliferation occurs mainly during winter under the stimulation of 11-KT induced by FSH through the stimulation of specific enzymes, including the 11β-hsd while spermiation occurs after photoperiod increase and with temperatures of the water below 23 °C, through the stimulation of gnrh-I, cyp19a1b and lhcgr.
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Affiliation(s)
- Mariano Elisio
- Laboratorio de Ictiofisiología y Acuicultura, Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús, (CONICET-UNSAM), Intendente Marino Km. 8.200 (B7130IWA), Chascomús, Buenos Aires, Argentina
| | - Tomás Chalde
- Laboratorio de Ictiofisiología y Acuicultura, Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús, (CONICET-UNSAM), Intendente Marino Km. 8.200 (B7130IWA), Chascomús, Buenos Aires, Argentina
| | - Leandro A Miranda
- Laboratorio de Ictiofisiología y Acuicultura, Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús, (CONICET-UNSAM), Intendente Marino Km. 8.200 (B7130IWA), Chascomús, Buenos Aires, Argentina.
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Abstract
We introduce a novel endocrine approach for assessing the unresolved matter of the timing of sexual maturation in western Atlantic bluefin tuna (ABFT), a highly migratory population whose status remains uncertain. Ratios of follicle stimulating hormone to luteinizing hormone, a sexual maturity indicator, in all ABFT ≥134 cm curved fork length (CFL) were <0.4, similar to Mediterranean spawners, indicating that western ABFT mature at considerably smaller sizes and at a much younger age than currently assumed (≥185 cm CFL).
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Elisio M, Chalde T, Miranda LA. Seasonal changes and endocrine regulation of pejerrey (Odontesthes bonariensis) oogenesis in the wild. Comp Biochem Physiol A Mol Integr Physiol 2014; 175:102-9. [DOI: 10.1016/j.cbpa.2014.05.020] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 05/21/2014] [Accepted: 05/23/2014] [Indexed: 02/06/2023]
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Shahjahan M, Kitahashi T, Parhar IS. Central pathways integrating metabolism and reproduction in teleosts. Front Endocrinol (Lausanne) 2014; 5:36. [PMID: 24723910 PMCID: PMC3971181 DOI: 10.3389/fendo.2014.00036] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 03/11/2014] [Indexed: 01/08/2023] Open
Abstract
Energy balance plays an important role in the control of reproduction. However, the cellular and molecular mechanisms connecting the two systems are not well understood especially in teleosts. The hypothalamus plays a crucial role in the regulation of both energy balance and reproduction, and contains a number of neuropeptides, including gonadotropin-releasing hormone (GnRH), orexin, neuropeptide-Y, ghrelin, pituitary adenylate cyclase-activating polypeptide, α-melanocyte stimulating hormone, melanin-concentrating hormone, cholecystokinin, 26RFamide, nesfatin, kisspeptin, and gonadotropin-inhibitory hormone. These neuropeptides are involved in the control of energy balance and reproduction either directly or indirectly. On the other hand, synthesis and release of these hypothalamic neuropeptides are regulated by metabolic signals from the gut and the adipose tissue. Furthermore, neurons producing these neuropeptides interact with each other, providing neuronal basis of the link between energy balance and reproduction. This review summarizes the advances made in our understanding of the physiological roles of the hypothalamic neuropeptides in energy balance and reproduction in teleosts, and discusses how they interact with GnRH, kisspeptin, and pituitary gonadotropins to control reproduction in teleosts.
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Affiliation(s)
- Md. Shahjahan
- Brain Research Institute, School of Medicine and Health Sciences, Monash University Malaysia, Petaling Jaya, Malaysia
| | - Takashi Kitahashi
- Brain Research Institute, School of Medicine and Health Sciences, Monash University Malaysia, Petaling Jaya, Malaysia
| | - Ishwar S. Parhar
- Brain Research Institute, School of Medicine and Health Sciences, Monash University Malaysia, Petaling Jaya, Malaysia
- *Correspondence: Ishwar S. Parhar, Brain Research Institute, School of Medicine and Health Sciences, Monash University Malaysia, Petaling Jaya 46150, Malaysia e-mail:
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Ryu YW, Hur SW, Hur SP, Lee CH, Lim BS, Lee YD. Characterization of Pubertal Development Phases in Female Longtooth Grouper, Epinephelus bruneus via Classification of Bodyweight. Dev Reprod 2013; 17:55-62. [PMID: 25949121 PMCID: PMC4282214 DOI: 10.12717/dr.2013.17.1.055] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2013] [Revised: 03/04/2013] [Accepted: 03/12/2013] [Indexed: 11/21/2022]
Abstract
Puberty is the developmental period which animals obtain the ability of reproducing sexually for the first time in life. In commercially important aquaculture fish species, the onset of puberty is a matter of major interest due to controlling of sexual maturation to improve broodstock management. To investigate pubertal characteristics of female longtooth grouper (Epinephelus bruneus), specimens were classified into three groups by the bodyweight, including 1, 2, and 3 kg group. Thereafter, we focused on ovarian development and level changes of endocrine regulation factors (GnRH, GTHs, steroid hormone). In the non-breeding season (April), the levels of endocrine regulation factors showed increasing trends in accordance with bodyweight gaining; nevertheless, the oocytes were growth phase belongs to almost peri-nucleous stages in all groups. In the breeding season (June), the levels of endocrine regulation factors were fluctuated that decreases in levels of sbGnRH and FSHβ mRNA expressions along with serum E2 concentrations in 3 kg of group. However, LHβ mRNA expression levels sustained increasing trends by the bodyweight. Moreover, the oocytes developed that 2 kg and 3 kg groups obtained plentiful vitellogenic oocytes while 1 kg group was still composed with greater part of pre-vitellogenic oocytes. Especially, the oocytes of 3 kg group reached over 450 μm of diameters that indicating possibility to enter the final maturations. These results suggest that the progress of pubertal development in female E. bruneus could be classify into three phases via bodyweight, including pre-puberty (1 kg), early-puberty (2 kg) and puberty (3 kg).
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Affiliation(s)
- Yong-Woon Ryu
- Marine and Environmental Research Institute, Jeju National University, Jeju 695-965, Korea
| | - Sang-Woo Hur
- Marine and Environmental Research Institute, Jeju National University, Jeju 695-965, Korea
| | - Sung-Pyo Hur
- Marine and Environmental Research Institute, Jeju National University, Jeju 695-965, Korea
| | - Chi-Hoon Lee
- Marine and Environmental Research Institute, Jeju National University, Jeju 695-965, Korea
| | - Bong-Soo Lim
- Marine and Environmental Research Institute, Jeju National University, Jeju 695-965, Korea
| | - Young-Don Lee
- Marine and Environmental Research Institute, Jeju National University, Jeju 695-965, Korea
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Qin F, Wang L, Wang X, Liu S, Xu P, Wang H, Wu T, Zhang Y, Zheng Y, Li M, Zhang X, Yuan C, Hu G, Wang Z. Bisphenol A affects gene expression of gonadotropin-releasing hormones and type I GnRH receptors in brains of adult rare minnow Gobiocypris rarus. Comp Biochem Physiol C Toxicol Pharmacol 2013; 157:192-202. [PMID: 23174456 DOI: 10.1016/j.cbpc.2012.11.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Revised: 11/13/2012] [Accepted: 11/13/2012] [Indexed: 01/07/2023]
Abstract
Recent studies support the notion that endocrine disrupting chemicals (EDCs) could affect the reproductive regulations of the neuroendocrine system. The objectives of the present study were to determine whether the weak estrogenic chemical, bisphenol A (BPA), disrupts gonadotropin-releasing hormone (GnRH) system by altering the transcription of GnRHs and GnRH receptor (GnRHR) genes in adult rare minnow Gobiocypris rarus. In the present study, the histological examination of the ovary after 35-day BPA exposure at 15 μg/L demonstrated the perturbing effects of environmentally relevant BPA on the ovarian development in G. rarus. In addition mRNA expression of ovarian P450 aromatase in both ovaries and testes were significantly down-regulated by 15 μg/L BPA. GnRH2, GnRH3, GnRHR1A and GnRHR1B gene were identified in G. rarus. The expression patterns of GnRHs and GnRHR1s were analyzed in various tissues of G. rarus by quantitative real-time PCR. GnRHs and GnRHR1s were all predominantly expressed in the brains. Both GnRH3 and GnRHR1A were significantly upregulated in the brains of female exposed to 15 μg/L BPA for 35 days. It would suggest a potential negative feedback in the GnRH system in response to the disturbance of downstream of the brain-pituitary-gonadal axis. Collectively, the present findings suggest that the transcripts of some key genes in the neuroendocrine system can be used as critical biomarkers in endocrine disruption assays of teleost fish.
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Affiliation(s)
- Fang Qin
- College of Animal Science and Technology, Northwest A&F University, Shaanxi Key Laboratory of Molecular Biology for Agriculture, Yangling, Shaanxi 712100 China
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15
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XU YONGJIANG, LIU XUEZHOU, LIAO MEIJIE, WANG HANPING, WANG QINGYIN. Molecular Cloning and Differential Expression of Three GnRH Genes during Ovarian Maturation of Spotted Halibut, Verasper variegatus. ACTA ACUST UNITED AC 2012; 317:434-46. [DOI: 10.1002/jez.1736] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Revised: 02/14/2012] [Accepted: 04/03/2012] [Indexed: 11/07/2022]
Affiliation(s)
| | - XUE-ZHOU LIU
- Yellow Sea Fisheries Research Institute; Chinese Academy of Fishery Sciences; Qingdao; Shandong; China
| | - MEI-JIE LIAO
- Yellow Sea Fisheries Research Institute; Chinese Academy of Fishery Sciences; Qingdao; Shandong; China
| | - HAN-PING WANG
- Aquaculture Genetics and Breeding Laboratory; The Ohio State University South Centers; Piketon; Ohio
| | - QING-YIN WANG
- Yellow Sea Fisheries Research Institute; Chinese Academy of Fishery Sciences; Qingdao; Shandong; China
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Hildahl J, Sandvik GK, Edvardsen RB, Fagernes C, Norberg B, Haug TM, Weltzien FA. Identification and gene expression analysis of three GnRH genes in female Atlantic cod during puberty provides insight into GnRH variant gene loss in fish. Gen Comp Endocrinol 2011; 172:458-67. [PMID: 21521645 DOI: 10.1016/j.ygcen.2011.04.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Revised: 04/06/2011] [Accepted: 04/08/2011] [Indexed: 10/18/2022]
Abstract
Gonadotropin releasing hormone (GnRH) is a key regulator of sexual development and reproduction in vertebrates. Fish have either two or three pre-pro-GnRH genes, encoding structurally distinct peptides. We identified three pre-pro-GnRH genes in Atlantic cod (Gadus morhua, gmGnRH) using RT-PCR, RACE-PCR and BAC DNA library clone sequencing based on synteny searching. Gene identity was confirmed by sequence alignment and subsequent phylogenetic analysis. The expression of these genes was measured by quantitative PCR in the brain and pituitary of female cod throughout their reproductive cycle and in peripheral tissues. All three gmGnRH genes have highly conserved deduced decapeptide sequences, but sequence and phylogenetic data for gmGnRH1 suggest that this is a pseudogene. gmGnRH1 shares low identity with all fish GnRH variants and grouped with the GnRH3 clade. Although gmGnRH1 is a putative pseudogene, it is transcribed in multiple tissues but at low levels in the brain, indicating the loss of conserved hypophysiotrophic function. Phylogenetic analysis reveals that gmGnRH2 and gmGnRH3 variants are located in variant-specific clades. Both gmGnRH2 and gmGnRH3 transcripts are most abundant in the brain, with lower expression in pituitaries and ovaries. Brain gmGnRH3 gene expression increases in spawning fish and is expressed in the pituitary during puberty. Brain gmGnRH2 transcripts are highly expressed relative to gmGnRH3 before and during spawning. Sequence and expression data suggest that gmGnRH1 is a pseudogene and that gmGnRH3 is likely the hypophysiotrophic form of GnRH in Atlantic cod.
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Affiliation(s)
- Jon Hildahl
- Norwegian School of Veterinary Science, Department of Basic Sciences and Aquatic Medicine, Oslo, Norway.
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17
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Guzmán JM, Cal R, García-López Á, Chereguini O, Kight K, Olmedo M, Sarasquete C, Mylonas CC, Peleteiro JB, Zohar Y, Mañanós EL. Effects of in vivo treatment with the dopamine antagonist pimozide and gonadotropin-releasing hormone agonist (GnRHa) on the reproductive axis of Senegalese sole (Solea senegalensis). Comp Biochem Physiol A Mol Integr Physiol 2011; 158:235-45. [DOI: 10.1016/j.cbpa.2010.11.016] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 11/18/2010] [Accepted: 11/19/2010] [Indexed: 01/04/2023]
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18
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Shahjahan M, Hamabata T, Motohashi E, Doi H, Ando H. Differential expression of three types of gonadotropin-releasing hormone genes during the spawning season in grass puffer, Takifugu niphobles. Gen Comp Endocrinol 2010; 167:153-63. [PMID: 20138178 DOI: 10.1016/j.ygcen.2010.01.018] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Revised: 01/28/2010] [Accepted: 01/31/2010] [Indexed: 11/26/2022]
Abstract
Grass puffer, Takifugu niphobles, has unique spawning behavior; spawning occurs on beach only for several days around new moon and full moon from spring to early summer. To investigate the role of gonadotropin-releasing hormone (GnRH) in the reproductive function, genes encoding three types of GnRHs, namely seabream GnRH (sbGnRH), chicken GnRH-II (cGnRH-II) and salmon GnRH (sGnRH), were cloned and changes in their mRNA amounts were examined over the spawning season. In addition, changes in the pituitary gonadotropin subunit mRNAs and the plasma steroid hormones were examined over the spawning season. Fishes were assessed at four reproductive stages, i.e., in December (early maturation), in April (maturing), in May (spawning), and in July (post-spawning). Moreover, spawning fish just after releasing eggs and sperm were taken at a spawning bed. The amounts of sbGnRH mRNA were substantially elevated in May and the spawning fish in both sexes, concomitant with considerable elevations of follicle-stimulating hormone and luteinizing hormone beta subunit mRNAs and plasma estradiol-17beta (E(2)) and testosterone (T) levels. There were strong positive correlations between the sbGnRH mRNA and the plasma E(2) and T levels over the spawning season in both sexes. The amounts of cGnRH-II mRNA showed no noticeable changes except for an increase in the post-spawning females. The amounts of sGnRH mRNA in the males were significantly increased in May, but they were low in the spawning males. In the females, sGnRH mRNA increased from the maturing stage and reached a maximum in the post-spawning stage, in which a positive correlation with the plasma cortisol levels was observed. These specific changes suggest that the expression of three types of GnRH genes is differentially regulated during the spawning season, and sex steroids may be important for the differential expression of GnRH genes.
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Affiliation(s)
- Md Shahjahan
- Laboratory of Advanced Animal and Marine Bioresources, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka 812-8581, Japan
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Selvaraj S, Kitano H, Fujinaga Y, Amano M, Takahashi A, Shimizu A, Yoneda M, Yamaguchi A, Matsuyama M. Immunological characterization and distribution of three GnRH forms in the brain and pituitary gland of chub mackerel (Scomber japonicus). Zoolog Sci 2010; 26:828-39. [PMID: 19968470 DOI: 10.2108/zsj.26.828] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The presence of three gonadotropin-releasing hormone (GnRH) forms in the brain of the chub mackerel, Scomber japonicus, namely, salmon GnRH (sGnRH), chicken GnRH-II (cGnRH-II), and seabream GnRH (sbGnRH), was confirmed by combined high performance liquid chromatography (HPLC) and time-resolved fluoroimmunoassay (TR-FIA). Immunocytochemical localization of the three GnRH forms in the brain was Investigated by using specific antisera, to elucidate possible roles of each GnRH form in reproduction in this species, and double immunolabeling was used to localize GnRH-ir (immunoreactive) fibers Innervating the pituitary. sGnRH-ir neurons were localized in the ventral olfactory bulb and terminal nerve ganglion region. Further, sGnRH-ir fibers were found in different regions of the brain, with prominent fibers running in parallel in the preoptic area (POA) without entering the pituitary. cGnRH-II-ir cell bodies were observed only in the midbrain tegmentum region, with a wide distribution of fibers, which were dense in the midbrain tegmentum and spinal cord. SbGnRH-ir cell bodies were localized in the nucleus preopticus of the POA, with fibers in the olfactory bulb, POA, and hypothalamus. Among the three GnRH forms, only SbGnRH-ir fibers innervated the pituitary gland from the preoptic-hypothalamic region, targeting follicle stimulating hormone (FSH) and luteinizing hormone (LH)-producing cells in the proximal pars distalis, as demonstrated by double immunocytochemistry. The localization of the GnRH-ir system was similar in male and female fish. These results demonstrate that multiple GnRH forms exist in the brain of the chub mackerel and suggest that they serve different functions, with SbGnRH having a significant role in reproduction in stimulating FSH- and LH-producing cells, and sGnRH and cGnRH-II serving as neurotransmitters or neuromodulators.
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Affiliation(s)
- Sethu Selvaraj
- Laboratory of Marine Biology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan
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20
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Zohar Y, Muñoz-Cueto JA, Elizur A, Kah O. Neuroendocrinology of reproduction in teleost fish. Gen Comp Endocrinol 2010; 165:438-55. [PMID: 19393655 DOI: 10.1016/j.ygcen.2009.04.017] [Citation(s) in RCA: 490] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Revised: 04/08/2009] [Accepted: 04/17/2009] [Indexed: 11/28/2022]
Abstract
This review aims at synthesizing the most relevant information regarding the neuroendocrine circuits controlling reproduction, mainly gonadotropin release, in teleost fish. In teleosts, the pituitary receives a more or less direct innervation by neurons sending projections to the vicinity of the pituitary gonadotrophs. Among the neurotransmitters and neuropeptides released by these nerve endings are gonadotrophin-releasing hormones (GnRH) and dopamine, acting as stimulatory and inhibitory factors (in many but not all fish) on the liberation of LH and to a lesser extent that of FSH. The activity of the corresponding neurons depends on a complex interplay between external and internal factors that will ultimately influence the triggering of puberty and sexual maturation. Among these factors are sex steroids and other peripheral hormones and growth factors, but little is known regarding their targets. However, very recently a new actor has entered the field of reproductive physiology. KiSS1, first known as a tumor suppressor called metastin, and its receptor GPR54, are now central to the regulation of GnRH, and consequently LH and FSH secretion in mammals. The KiSS system is notably viewed as instrumental in integrating both environmental cues and metabolic signals and passing this information onto the reproductive axis. In fish, there are two KiSS genes, KiSS1 and KiSS2, expressed in neurons of the preoptic area and mediobasal hypothalamus. Pionneer studies indicate that KiSS and GPR54 expression seem to be activated at puberty. Although precise information as to the physiological effects of KiSS1 in fish, notably on GnRH neurons and gonadotropin release, is still limited, KiSS neurons may emerge as the "gatekeeper" of puberty and reproduction in fish as in mammals.
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Affiliation(s)
- Yonathan Zohar
- Center of Marine Biotechnology, University of Maryland Biotechnology Institute, Baltimore, MD, USA
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21
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Clelland E, Peng C. Endocrine/paracrine control of zebrafish ovarian development. Mol Cell Endocrinol 2009; 312:42-52. [PMID: 19406202 DOI: 10.1016/j.mce.2009.04.009] [Citation(s) in RCA: 162] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2008] [Revised: 04/16/2009] [Accepted: 04/17/2009] [Indexed: 12/11/2022]
Abstract
Ovarian differentiation and the processes of follicle development, oocyte maturation and ovulation are complex events, requiring the coordinated action of regulatory molecules. In zebrafish, ovarian development is initiated at 10 days after hatching and fish become sexually mature at 3 months. Adult zebrafish have asynchronous ovaries, which contain follicles of all stages of development. Eggs are spawned daily under proper environmental conditions in a population of zebrafish, with individual females spawning irregularly every 4-7 days in mixed sex conditions. Maximal embryo viability is achieved when sexually isolated females are bred in 10-day intervals [Niimi, A.J., LaHam, Q.N., 1974. Influence of breeding time interval on egg number, mortality, and hatching of the zebra fish Brachydanio verio. Can. J. Zool. 52, 515-517]. Similar to other vertebrates, hormones from the hypothalamus-pituitary-gonadal axis play important roles in regulating follicle development. Follicle stimulating hormone (FSH) stimulates estradiol production, which in turn, promotes viteollogenesis. Luteinizing hormone (LH) stimulates the production of 17,20beta-dihydroxy-4-pregnen-3-one (17,20betaP) or maturation inducing hormone (MIH) which acts through membrane progestin receptors to activate maturation promoting factor, leading to oocyte maturation. Recent studies in zebrafish have also provided novel insights into the functions of ovary-derived growth factors in follicle development and oocyte maturation. The present review summarizes the current knowledge on how endocrine and paracrine factors regulate ovarian development in zebrafish. Special emphasis is placed on how follicle development and oocyte maturation in adult females is regulated by gonadotropins, ovarian steroids and growth factors produced by the ovary.
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Affiliation(s)
- Eric Clelland
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada
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22
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Carrillo M, Zanuy S, Felip A, Bayarri MJ, Molés G, Gómez A. Hormonal and Environmental Control of Puberty in Perciform Fish. Ann N Y Acad Sci 2009; 1163:49-59. [DOI: 10.1111/j.1749-6632.2008.03645.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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23
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Guzmán JM, Rubio M, Ortiz-Delgado JB, Klenke U, Kight K, Cross I, Sánchez-Ramos I, Riaza A, Rebordinos L, Sarasquete C, Zohar Y, Mañanós EL. Comparative gene expression of gonadotropins (FSH and LH) and peptide levels of gonadotropin-releasing hormones (GnRHs) in the pituitary of wild and cultured Senegalese sole (Solea senegalensis) broodstocks. Comp Biochem Physiol A Mol Integr Physiol 2009; 153:266-77. [PMID: 19264148 DOI: 10.1016/j.cbpa.2009.02.032] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2008] [Revised: 02/20/2009] [Accepted: 02/20/2009] [Indexed: 10/21/2022]
Abstract
The Senegalese sole (Solea senegalensis) is a valuable flatfish for aquaculture, but it presents important reproductive problems in captivity. Spawning is achieved by wild-caught breeders but cultured broodstocks fail to spawn spontaneously and, when they do, eggs are unfertilized. To gain knowledge on the physiological basis underlying this reproductive dysfunction, this study aimed at analyzing comparative hormone levels between wild and cultured broodstocks at the spawning season. The Senegalese sole gonadotropin (GTH) subunits, FSHbeta, LHbeta and GPalpha, were cloned and qualitative (in situ hybridization) and quantitative (real-time PCR) assays developed to analyze pituitary GTH gene expression. In females, FSHbeta and GPalpha mRNA levels were higher in wild than in cultured broodstocks, whereas in males all three subunits were highest in cultured. By ELISA, three GnRH forms were detected in the pituitary, displaying a relative abundance of GnRH2>GnRH1>GnRH3. All GnRHs were slightly more abundant in wild than cultured females, whereas no differences were observed in males. Plasma levels of vitellogenin and sex steroids were also analyzed. Results showed endocrine differences between wild and cultured broodstocks at the spawning period, which could be related to the endocrine failure of the reproductive axis in cultured breeders.
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Affiliation(s)
- J M Guzmán
- Institute of Aquaculture of Torre Sal, Spanish Council for Scientific Research (CSIC), Torre Sal s/n, 12595-Cabanes, Castellón, Spain
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24
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Guilgur LG, Strüssmann CA, Somoza GM. mRNA expression of GnRH variants and receptors in the brain, pituitary and ovaries of pejerrey (Odontesthes bonariensis) in relation to the reproductive status. FISH PHYSIOLOGY AND BIOCHEMISTRY 2009; 35:157-166. [PMID: 19189242 DOI: 10.1007/s10695-008-9215-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2008] [Accepted: 03/20/2008] [Indexed: 05/27/2023]
Abstract
The present study examined the differential mRNA expression levels of three forms of GnRH (sGnRH, pjGnRH and cGnRH-II) and two forms of GnRH receptor (pjGnRH-R I and pjGnRH-R II) in the brain, pituitary, and ovaries of pejerrey in relation to the reproductive status. The analysis revealed the presence of significant amounts of mRNA of the three GnRH forms while the ovaries showed only two (sGnRH and pjGnRH). The GnRH receptor II was found ubiquitously in the brain, pituitary, and ovaries while the form I was detected only in the brain. The levels of pjGnRH mRNA in the brain and pjGnRH-R II in the pituitary gland varied in correlation with the ovarian condition. However, brain sGnRH and pjGnRH-R I mRNA levels reached a maximum during early stages of ovarian development. In contrast, the brain levels of cGnRH-II mRNA showed no variation. The present study also shows a good correlation of ovarian sGnRH and pjGnRH-R II mRNA levels with the reproductive condition, suggesting that these molecules are may be involved in the regulation of pejerrey ovarian function.
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Affiliation(s)
- L G Guilgur
- Laboratorio de Ictiofisiología y Acuicultura, Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico Chascomús, Chascomús, Buenos Aires, Argentina
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25
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Canosa LF, Stacey N, Peter RE. Changes in brain mRNA levels of gonadotropin-releasing hormone, pituitary adenylate cyclase activating polypeptide, and somatostatin during ovulatory luteinizing hormone and growth hormone surges in goldfish. Am J Physiol Regul Integr Comp Physiol 2008; 295:R1815-21. [DOI: 10.1152/ajpregu.00166.2008] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In goldfish, circulating LH and growth hormone (GH) levels surge at the time of ovulation. In the present study, changes in gene expression of salmon gonadotropin-releasing hormone (sGnRH), chicken GnRH-II (cGnRH-II), somatostatin (SS) and pituitary adenylate cyclase activating polypeptide (PACAP) were analyzed during temperature- and spawning substrate-induced ovulation in goldfish. The results demonstrated that increases in PACAP gene expression during ovulation are best correlated with the GH secretion profile. These results suggest that PACAP, instead of GnRH, is involved in the control of GH secretion during ovulation. Increases of two of the SS transcripts during ovulation are interpreted as the activation of a negative feedback mechanism triggered by high GH levels. The results showed a differential regulation of sGnRH and cGnRH-II gene expression during ovulation, suggesting that sGnRH controls LH secretion, whereas cGnRH-II correlates best with spawning behavior. This conclusion is further supported by the finding that nonovulated fish induced to perform spawning behavior by prostaglandin F2α treatment increased cGnRH-II expression in both forebrain and midbrain, but decreased sGnRH expression in the forebrain.
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26
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Amano M, Pham KX, Amiya N, Yamanome T, Yamamori K. Changes in brain seabream GnRH mRNA and pituitary seabream GnRH peptide levels during ovarian maturation in female barfin flounder. Gen Comp Endocrinol 2008; 158:168-72. [PMID: 18662692 DOI: 10.1016/j.ygcen.2008.06.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2008] [Revised: 06/03/2008] [Accepted: 06/29/2008] [Indexed: 11/28/2022]
Abstract
The pleuronectid barfin flounder Verasper moseri expresses three forms of gonadotropin-releasing hormones (GnRHs), i.e., seabream GnRH (sbGnRH), salmon GnRH, and chicken GnRH-II. Among these, sbGnRH is the dominant form in the pituitary, indicating that sbGnRH regulates gonadal maturation. In order to clarify the physiological roles of sbGnRH during ovarian maturation in reared female barfin flounder, the changes in brain sbGnRH mRNA levels and pituitary sbGnRH peptide levels were examined by real-time quantitative PCR and time-resolved fluoroimmunoassay, respectively. The fish hatched in April 2002. The gonadosomatic index remained low until August 2004 and increased thereafter until April 2005 when the fish began to ovulate. The sbGnRH mRNA levels per brain increased significantly from April 2004 to April 2005. Pituitary sbGnRH peptide levels also increased significantly during this period. These results indicate that sbGnRH is involved in ovarian maturation and ovulation in the barfin flounder.
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Affiliation(s)
- Masafumi Amano
- School of Marine Biosciences, Kitasato University, Sanriku, Ofunato, Iwate 022-0101, Japan.
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27
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Maruska KP, Mizobe MH, Tricas TC. Sex and seasonal co-variation of arginine vasotocin (AVT) and gonadotropin-releasing hormone (GnRH) neurons in the brain of the halfspotted goby. Comp Biochem Physiol A Mol Integr Physiol 2006; 147:129-44. [PMID: 17276115 DOI: 10.1016/j.cbpa.2006.12.019] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Revised: 12/04/2006] [Accepted: 12/05/2006] [Indexed: 10/23/2022]
Abstract
Gonadotropin-releasing hormone (GnRH) and arginine vasotocin (AVT) are critical regulators of reproductive behaviors that exhibit tremendous plasticity, but co-variation in discrete GnRH and AVT neuron populations among sex and season are only partially described in fishes. We used immunocytochemistry to examine sexual and temporal variations in neuron number and size in three GnRH and AVT cell groups in relation to reproductive activities in the halfspotted goby (Asterropteryx semipunctata). GnRH-immunoreactive (-ir) somata occur in the terminal nerve, preoptic area, and midbrain tegmentum, and AVT-ir somata within parvocellular, magnocellular, and gigantocellular regions of the preoptic area. Sex differences were found among all GnRH and AVT cell groups, but were time-period dependent. Seasonal variations also occurred in all GnRH and AVT cell groups, with coincident elevations most prominent in females during the peak- and non-spawning periods. Sex and temporal variability in neuropeptide-containing neurons are correlated with the goby's seasonally-transient reproductive physiology, social interactions, territoriality and parental care. Morphological examination of GnRH and AVT neuron subgroups within a single time period provides detailed information on their activities among sexes, whereas seasonal comparisons provide a fine temporal sequence to interpret the proximate control of reproduction and the evolution of social behavior.
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Affiliation(s)
- Karen P Maruska
- Department of Zoology, University of Hawai'i at Manoa, 2538 The Mall, Honolulu, HI 96822, USA.
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Scaggiante M, Grober MS, Lorenzi V, Rasotto MB. Variability of GnRH secretion in two goby species with socially controlled alternative male mating tactics. Horm Behav 2006; 50:107-17. [PMID: 16530763 DOI: 10.1016/j.yhbeh.2006.01.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2005] [Revised: 12/20/2005] [Accepted: 01/04/2006] [Indexed: 10/24/2022]
Abstract
Male reproductive phenotypic plasticity related to environmental-social conditions is common among teleost fish. In several species, males adopt different mating tactics depending on their size, monopolizing mates when larger, while parasitizing dominant male spawns when smaller. Males performing alternative mating tactics are often characterized by a strong dimorphism in both primary and secondary reproductive traits. According to studies on sex-changing species and on species where only one male morph is reproductively active, male alternative phenotypes are expected to vary also in gonadotropin-releasing hormone (GnRH) neurons in forebrain preoptic area (POA). Here, we compared the intra- and inter-sexual variations in number and size of GnRH neurons, along with gonads and male accessory structure investment, in two goby species, the grass goby, Zosterisessor ophiocephalus, and the black goby, Gobius niger, characterized by male alternative mating phenotypes. In both species, older and larger males defend nests, court and perform parental care, while younger and smaller ones try to sneak territorial male spawning. We found that grass goby and black goby have different patterns of GnRH expression. Grass goby presents a clear intra-sexual dimorphism in GnRH expression, related to the occurrence of alternative mating tactics, while in the black goby, only inter-sexual differences are observed. The inter- and intra-specific variability in the GnRH neurons in these two goby species is discussed in light of the differences in migratory behavior, nest type, and mating system.
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Affiliation(s)
- Marta Scaggiante
- Department of Biology, University of Padova, Viale G. Colombo 3, 35131 Padova, Italy
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Amano M, Okubo K, Yamanome T, Yamada H, Aida K, Yamamori K. Changes in brain GnRH mRNA and pituitary GnRH peptide during testicular maturation in barfin flounder. Comp Biochem Physiol B Biochem Mol Biol 2005; 138:435-43. [PMID: 15325345 DOI: 10.1016/j.cbpc.2004.05.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2003] [Revised: 04/18/2004] [Accepted: 05/31/2004] [Indexed: 10/26/2022]
Abstract
The pleuronectid barfin flounder (Verasper moseri) expresses three forms of gonadotropin-releasing hormone (GnRH) in the brain. To clarify the physiological roles of the respective forms during testicular maturation, changes in brain GnRH mRNA levels and pituitary GnRH peptide levels were examined by real-time quantitative PCR and time-resolved fluoroimmunoassay, respectively. Fish hatched in April 2000. The gonadosomatic index remained low until October 2001 and then rapidly increased in January 2002. Fish continued to grow from hatching through testicular maturation. Fish spermiated in March 2002. The amount of seabream GnRH (sbGnRH) mRNA per brain significantly increased in January 2002 and remained at high levels in March 2002. The amounts of salmon GnRH (sGnRH) and chicken GnRH-II (cGnRH-II) mRNA per brain did not show significant changes during the experimental periods. Pituitary sbGnRH peptide content significantly increased in March 2002. Pituitary sGnRH peptide and cGnRH-II peptide contents were extremely low compared to sbGnRH peptide levels and showed no significant changes during the experiment. These results indicate that sbGnRH is involved in the testicular maturation of barfin flounder.
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Affiliation(s)
- Masafumi Amano
- School of Fisheries Sciences, Kitasato University, Sanriku, Ofunato, Iwate 022-0101, Japan.
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Weltzien FA, Andersson E, Andersen Ø, Shalchian-Tabrizi K, Norberg B. The brain–pituitary–gonad axis in male teleosts, with special emphasis on flatfish (Pleuronectiformes). Comp Biochem Physiol A Mol Integr Physiol 2004; 137:447-77. [PMID: 15123185 DOI: 10.1016/j.cbpb.2003.11.007] [Citation(s) in RCA: 209] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2003] [Revised: 11/05/2003] [Accepted: 11/06/2003] [Indexed: 02/03/2023]
Abstract
The key component regulating vertebrate puberty and sexual maturation is the endocrine system primarily effectuated along the brain-pituitary-gonad (BPG) axis. By far most investigations on the teleost BPG axis have been performed on salmonids, carps, catfish and eels. Accordingly, earlier reviews on the BPG axis in teleosts have focused on these species, and mainly on females (e.g. 'Fish Physiology, vol. IXA. Reproduction (1983) pp. 97'; 'Proceedings of the Fourth International Symposium on the Reproductive Physiology of Fish. FishSymp91, Sheffield, UK, 1991, pp. 2'; 'Curr. Top. Dev. Biol. 30 (1995) pp. 103'; 'Rev. Fish Biol. Fish. 7 (1997) pp. 173'; 'Proceedings of the Sixth International Symposium on the Reproductive Physiology of Fish. John Grieg A/S, Bergen, Norway, 2000, pp. 211'). However, in recent years new data have emerged on the BPG axis in flatfish, especially at the level of the brain and pituitary. The evolutionarily advanced flatfishes are important model species both from an evolutionary point of view and also because many are candidates for aquaculture. The scope of this paper is to review the present status on the male teleost BPG axis, with an emphasis on flatfish. In doing so, we will first discuss the present understanding of the individual constituents of the axis in the best studied teleost models, and thereafter discuss available data on flatfish. Of the three constituents of the BPG axis, we will focus especially on the pituitary and gonadotropins. In addition to reviewing recent information on flatfish, we present some entirely new information on the phylogeny and molecular structure of teleost gonadotropins.
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Affiliation(s)
- Finn-Arne Weltzien
- Institute of Marine Research, Austevoll Aquaculture Research Station, 5392 Storebø, Norway.
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Steven C, Lehnen N, Kight K, Ijiri S, Klenke U, Harris WA, Zohar Y. Molecular characterization of the GnRH system in zebrafish (Danio rerio): cloning of chicken GnRH-II, adult brain expression patterns and pituitary content of salmon GnRH and chicken GnRH-II. Gen Comp Endocrinol 2003; 133:27-37. [PMID: 12899844 DOI: 10.1016/s0016-6480(03)00144-8] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The zebrafish has proven to be a model system with unparalleled utility in vertebrate genetic and developmental studies. Substantially less attention has been paid to the potential role that zebrafish can play in answering important questions of vertebrate reproductive endocrinology. As an initial step towards exploiting the advantages that the zebrafish model offers, we have characterized their gonadotropin-releasing hormone (GnRH) system at the molecular level. GnRHs comprise a family of highly conserved decapeptide neurohormones widely recognized to orchestrate the hormonal control of reproduction in all vertebrates. We have isolated the gene and cDNA encoding chicken GnRH-II (cGnRH-II) from zebrafish, as well as several kilobases of upstream promoter sequence for this gene. As the gene encoding salmon GnRH (sGnRH) has been previously isolated (Torgersen et al, 2002), this is the second GnRH gene isolated from zebrafish to date. We have localized expression of these two genes in the brains of reproductively mature zebrafish using in situ hybridization. sGnRH is localized to the olfactory bulb-terminal nerve region (OB-TN), the ventral telencephalon-preoptic area (VT-POA) and, as we report here for the first time in any teleost species, the hindbrain. cGnRH-II is expressed exclusively in the midbrain, as has been found in all other jawed vertebrate species examined. Finally, the levels of both GnRH peptides in pituitaries of reproductively mature zebrafish were quantified using specific ELISAs. sGnRH pituitary peptide levels were shown to be 3- to 4-fold higher than cGnRH-II pituitary peptide. The cumulative results of these experiments allow us to conclude that zebrafish express just two forms of GnRH in a site-specific manner within the brain, and that sGnRH is the hypophysiotropic GnRH form. This work lays the foundation for further research into the control of reproduction in zebrafish, such as the functional significance of multiple GnRHs in vertebrates, and the molecular mechanisms controlling tissue-specific GnRH expression.
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Affiliation(s)
- Colin Steven
- Center of Marine Biotechnology, University of Maryland Biotechnology Institute, 701 E Pratt Street, Baltimore, MD 21202, USA
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Okuzawa K, Kumakura N, Mori A, Gen K, Yamaguchi S, Kagawa H. Regulation of GnRH and its receptor in a teleost, red seabream. PROGRESS IN BRAIN RESEARCH 2003; 141:95-110. [PMID: 12508564 DOI: 10.1016/s0079-6123(02)41087-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Affiliation(s)
- Koichi Okuzawa
- Inland Station, National Research Institute of Aquaculture, Fisheries Research Agency, 224-1, Hiruta, Tamaki, Watarai, Mie 519-0423, Japan.
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Farahmand H, Rahman MA, Sohm F, Hwang GL, Maclean N. Isolation and expression of tilapia (Oreochromis niloticus) serine 8-type GnRH coding and regulatory sequences. Gene 2003; 304:97-106. [PMID: 12568719 DOI: 10.1016/s0378-1119(02)01184-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The complete Serine 8-type gonadotropin releasing hormone (GnRH) coding sequence with a substantial 5-prime regulatory sequence (5 kb) has been isolated and characterised in Nile Tilapia (Oreochromis niloticus) from a relevant genomic library. The primary structure of the protein precursor was identified for this gene. The promoter efficacy has been tested using 0.6 kb of the GnRH promoter driving a lacZ reporter gene in both cultured spleen cells and transiently expressing zebrafish. In the cell transfection experiments, the average level of beta-galactosidase activity in transfected cells was more than 2.1 (P<0.05) times higher than the control promoter-less vector in five independent cultures indicating that the 0.6 GnRH/lacZ construct is able to express in spleen cells. In addition, the transient expression of the lacZ gene was detected in the brain of G0 zebrafish embryos (Danio rerio) 4 days after fertilisation following egg injection with the construct, which demonstrated the efficacy of the tilapia GnRH promoter.
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Affiliation(s)
- Hamid Farahmand
- University of Southampton, School of Biological Sciences, Division of Cell Sciences, Biomedical Sciences Building, Bassett Crescent East, Southampton SO16 7PX, UK
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Somoza GM, Miranda LA, Strobl-Mazzulla P, Guilgur LG. Gonadotropin-releasing hormone (GnRH): from fish to mammalian brains. Cell Mol Neurobiol 2002; 22:589-609. [PMID: 12838906 DOI: 10.1023/a:1021888420271] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This work deals with a family of neuropeptides, gonadotropin-releasing hormone (GnRH), that play a key role in the development and maintenance of reproductive function in vertebrates. 2. Until now, a total of 16 GnRH structural variants have been isolated and characterized from vertebrate and protochordate nervous tissue. All vertebrate species already investigated have at least two GnRH forms coexisting in the central nervous system. However, it is now well accepted that three forms of GnRH in early and late evolved bony fishes are present. 3. In these cases, cGnRH-II is expressed by midbrain neurons, a species-specific GnRH is present mainly in the preoptic area and the hypothalamus, and sGnRH is localized in the terminal nerve ganglion (TNG). In this context it is possible to think that three GnRH forms and three GnRH receptor (GnRH-R) subtypes are expressed in the central nervous system of a given species. 4. Then it is possible to propose three different GnRH lineages expressed by distinct brain areas in vertebrates: (1) the conserved cGnRH-II or mesencephalic lineage; or (2) the hypothalamic or "releasing" lineage whose primary structure has diverged by point mutations (mGnRH and its orthologous forms: hrGnRH, wfGnRH, cfGnRH, sbGnRH, and pjGnRH); and (3) the telencephalic sGnRH form. Also different GnRH nomenclatures are discussed.
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Affiliation(s)
- Gustavo M Somoza
- Laboratorio de Ictiofisiología, Instituto Tecnológico, Universidad Nacional de General San Martín, Chascomús, Buenos Aires, Argentina.
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Somoza GM, Lescheid DW, Miranda LA, Lo Nostro FL, Magliulo-Cepriano L, Montaner AD, Schreibman MP, Rivier JE, Sherwood NM. Expression of pejerrey gonadotropin-releasing hormone in three orders of fish. Biol Reprod 2002; 67:1864-71. [PMID: 12444064 DOI: 10.1095/biolreprod.102.004572] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Molecular variants of GnRH were characterized by reverse-phase, high-performance liquid chromatography from brain extracts of fish in three different orders: Synbranchiformes (swamp eel [Synbranchus marmoratus]), Cyprinidontiformes (platyfish [Xiphophorus maculatus] and green swordtail [X. helleri]), and Atheriniformes (Patagonia pejerrey [Odontesthes hatchery]). Also, pituitary gland extracts from the pejerrey O. bonariensis (Atheriniformes) were characterized. Eluted fractions were tested in radioimmunoassays with antisera specific to GnRH, including both antisera that detected only one form of GnRH and those that detected several forms. The results show that brain extracts obtained from all species contained the same three molecular forms of GnRH, which were immunologically and chromatographically undistinguishable from chicken GnRH-II, pejerrey GnRH (pjGnRH), and salmon GnRH. This study supports the hypothesis that expression of these three forms is common in different fish orders and that pjGnRH is the main regulator of pituitary function in these fish.
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Affiliation(s)
- G M Somoza
- Instituto Tecnológico de Chascomús (IIB-INTECH, CONICET-Universidad de San Martín), Camino de Circunvalación Laguna, Km 6. CC 164 (B7130IWA) Chascomús, Provincia de Buenos Aires, Argentina.
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Amano M, Takahashi A, Yamanome T, Okubo K, Aida K, Yamamori K. Molecular cloning of three cDNAs encoding different GnRHs in the brain of barfin flounder. Gen Comp Endocrinol 2002; 126:325-33. [PMID: 12093120 DOI: 10.1016/s0016-6480(02)00008-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To examine the reproductive endocrinology of a large pleuronectiform fish, barfin flounder, Verasper moseri, a promising candidate for aquaculture and resource enhancement in northern Japan due to its high commercial value, three gonadotropin-releasing hormones (GnRHs) in the brain was identified by isolation of their cDNAs. This species had three molecular forms of GnRH; salmon GnRH (sGnRH), chicken GnRH-II (cGnRH-II), and seabream GnRH (sbGnRH). Each GnRH cDNA encoded a signal peptide (SP), GnRH, and a GnRH-associated peptide (GAP), which was connected to GnRH by a Gly-Lys-Arg sequence. The sGnRH cDNA encoded an SP composed of 23 amino acids and a GAP composed of 54 amino acids. The cGnRH-II cDNA encoded an SP of 23 amino acids and a GAP of 49 amino acids. The sbGnRH cDNA encoded an SP of 26 amino acids and a GAP of 57 amino acids. In situ hybridization showed that the genes for sGnRH, cGnRH-II, and sbGnRH are expressed in the ventromedial olfactory bulbs and the terminal nerve ganglion, the midbrain tegmentum, and the preoptic area, respectively. These results indicate that sbGnRH neurons in the preoptic area are involved in gonadotropin secretion in barfin flounder.
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Affiliation(s)
- Masafumi Amano
- School of Fisheries Sciences, Kitasato University, Sanriku Ofunato, Iwate 022-0101, Japan.
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Yamada H, Amano M, Okuzawa K, Chiba H, Iwata M. Maturational changes in brain contents of salmon GnRH in rainbow trout as measured by a newly developed time-resolved fluoroimmunoassay. Gen Comp Endocrinol 2002; 126:136-43. [PMID: 12030769 DOI: 10.1006/gcen.2002.7791] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A newly developed time-resolved fluoroimmunoassay (TR-FIA) for salmon gonadotropin-releasing hormone (sGnRH) was applied to investigate changes in sGnRH content in discrete brain areas at three different gonadal stages in the rainbow trout, Oncorhynchus mykiss. The sensitivity (6.8 pg/well), specificity, intraassay coefficients of variation (<7.4%), and interassay coefficients of variation (<10.3%) of the assay system were almost the same as those for the radioimmunoassay. Displacement curves of serially diluted brain extracts of nine teleost fish (freshwater fish and seawater fish) including rainbow trout paralleled that of the sGnRH standard, indicating that the sGnRH TR-FIA is widely applicable to the measurement of the brain sGnRH contents of various fishes. The sGnRH content in female hypothalamus decreased during final gonad maturation, whereas the sGnRH levels in pituitary were highest at the time of spermiating in males or ovulating in females, decreasing significantly thereafter. In contrast, there were no changes in the sGnRH contents of olfactory bulbs, telencephalon, optic tectum + thalamus, and cerebellum + medulla oblongata during final maturation, except for olfactory bulbs of males. Changes in sGnRH contents in the hypothalamus and the pituitary indicate that sGnRH is involved in final maturation (ovulation or spermiation) in the rainbow trout.
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Affiliation(s)
- Hideaki Yamada
- School of Fisheries Sciences, Kitasato University, Sanriku, Ofunato, Iwate 022-0101, Japan
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