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Zhang J, Lv C, Mo C, Liu M, Wan Y, Li J, Wang Y. Single-Cell RNA Sequencing Analysis of Chicken Anterior Pituitary: A Bird's-Eye View on Vertebrate Pituitary. Front Physiol 2021; 12:562817. [PMID: 34267669 PMCID: PMC8276247 DOI: 10.3389/fphys.2021.562817] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 05/21/2021] [Indexed: 01/08/2023] Open
Abstract
It is well-established that anterior pituitary contains multiple endocrine cell populations, and each of them can secrete one/two hormone(s) to regulate vital physiological processes of vertebrates. However, the gene expression profiles of each pituitary cell population remains poorly characterized in most vertebrate groups. Here we analyzed the transcriptome of each cell population in adult chicken anterior pituitaries using single-cell RNA sequencing technology. The results showed that: (1) four out of five known endocrine cell clusters have been identified and designated as the lactotrophs, thyrotrophs, corticotrophs, and gonadotrophs, respectively. Somatotrophs were not analyzed in the current study. Each cell cluster can express at least one known endocrine hormone, and novel marker genes (e.g., CD24 and HSPB1 in lactotrophs, NPBWR2 and NDRG1 in corticotrophs; DIO2 and SOUL in thyrotrophs, C5H11ORF96 and HPGDS in gonadotrophs) are identified. Interestingly, gonadotrophs were shown to abundantly express five peptide hormones: FSH, LH, GRP, CART and RLN3; (2) four non-endocrine/secretory cell types, including endothelial cells (expressing IGFBP7 and CFD) and folliculo-stellate cells (FS-cells, expressing S100A6 and S100A10), were identified in chicken anterior pituitaries. Among them, FS-cells can express many growth factors, peptides (e.g., WNT5A, HBEGF, Activins, VEGFC, NPY, and BMP4), and progenitor/stem cell-associated genes (e.g., Notch signaling components, CDH1), implying that the FS-cell cluster may act as a paracrine/autocrine signaling center and enrich pituitary progenitor/stem cells; (3) sexually dimorphic expression of many genes were identified in most cell clusters, including gonadotrophs and lactotrophs. Taken together, our data provides a bird's-eye view on the diverse aspects of anterior pituitaries, including cell composition, heterogeneity, cell-to-cell communication, and gene expression profiles, which facilitates our comprehensive understanding of vertebrate pituitary biology.
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Affiliation(s)
- Jiannan Zhang
- Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Can Lv
- Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Chunheng Mo
- Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Meng Liu
- Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Yiping Wan
- Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Juan Li
- Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Yajun Wang
- Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
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Di Fiore MM, Santillo A, Falvo S, Pinelli C. Celebrating 50+ years of research on the reproductive biology and endocrinology of the green frog: An overview. Gen Comp Endocrinol 2020; 298:113578. [PMID: 32739437 DOI: 10.1016/j.ygcen.2020.113578] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 07/20/2020] [Accepted: 07/25/2020] [Indexed: 12/30/2022]
Abstract
This issue is dedicated to the late Professor Giovanni Chieffi, and this article is an overview of the research on Comparative Endocrinology of reproduction using Rana esculenta (alias Pelophylax esculentus) as a model system. Starting from the early 1970s till today, a large quantity of work have been conducted both in the fields of experimental endocrinology and in the definition of the diffuse neuroendocrine system, with a major focus on the increasing role of regulatory peptides. The various aspects investigated concerned the histological descriptions of principal endocrine glands of the hypothalamic-pituitary-gonadal (HPG) axis, the localization and distribution in the HPG of several different substances (i.e. neurosteroids, hypothalamic peptide hormones, pituitary gonadotropins, gonadal sex steroids, and other molecules), the determination of sex hormone concentrations in both serum and tissues, the hormone manipulations, as well as the gene and protein expression of steroidogenic enzymes and their respective receptors. All together these researches, often conducted considering different periods of the annual reproductive cycle of the green frog, allowed to understand the mechanism of cascade control/regulation of the HPG axis of R. esculenta, characterizing the role of different hormones in the two sexes, and testing the hypotheses about the function of single hormones in different target organs. It becomes evident from the review that, in their simplest form, several features of this species are specular as compared to those of other vertebrate species and that reproduction in this frog species is either under endogenous multi-hormonal control or by a wide array of different factors. Our excursus of this research, spanning almost five decades, shows that R. esculenta has been intensively and successfully used as an animal model in reproductive endocrinology as well as several field studies such as those involving environmental concerns that focus on the effects of endocrine disruptors and other environmental contaminants.
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Affiliation(s)
- Maria Maddalena Di Fiore
- Department of Environmental, Biological and Pharmaceutical Sciences & Technologies, University of Campania "Luigi Vanvitelli", Caserta, Italy
| | - Alessandra Santillo
- Department of Environmental, Biological and Pharmaceutical Sciences & Technologies, University of Campania "Luigi Vanvitelli", Caserta, Italy
| | - Sara Falvo
- Department of Environmental, Biological and Pharmaceutical Sciences & Technologies, University of Campania "Luigi Vanvitelli", Caserta, Italy
| | - Claudia Pinelli
- Department of Environmental, Biological and Pharmaceutical Sciences & Technologies, University of Campania "Luigi Vanvitelli", Caserta, Italy.
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Scaia MF, Volonteri MC, Czuchlej SC, Ceballos NR. Estradiol and reproduction in the South American toad Rhinella arenarum (Amphibian, Anura). Gen Comp Endocrinol 2019; 273:20-31. [PMID: 29555118 DOI: 10.1016/j.ygcen.2018.03.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 02/24/2018] [Accepted: 03/14/2018] [Indexed: 12/28/2022]
Abstract
Rhinella arenarum is a South American toad with wide geographic distribution. Testes of this toad produce high amount of androgens during the non reproductive season and shift steroid synthesis from androgens to 5α-pregnanedione during the breeding. In addition, plasma estradiol (E2) in males of this species shows seasonal variations but, since testes of R. arenarum do not express aromatase, the source of plasma E2 remained unknown for several years. However, the Bidder's organ (BO), a structure located at one pole of each testis, is proposed to be the main source of E2 in male's toads since it expresses several steroidogenic enzymes and is able to produce E2 from endogenous substrates throughout the year. In addition, there were significant correlations between plasma E2 and total activity of BO aromatase, and between plasma E2 and the amount of hormone produced by the BO in vitro. In the toad, apoptosis induced by in vitro treatment with E2 was mostly detected in spermatocytes during the breeding and in spermatids during the post-reproductive season, suggesting that this steroid has an important role in controlling spermatogenesis. However, in vitro treatment with E2 had no effect on proliferation. This evidence suggests that the mechanism of action of E2 on amphibian spermatogenesis is complex and more studies are necessary to fully understand the role of estrogens regulating the balance between cellular proliferation and apoptosis. In addition, in R. arenarum in vitro studies suggested that E2 has no effect on CypP450c17 protein levels or enzymatic activity, while it reduces 3β-hydroxysteroid dehydrogenase/isomerase (3β-HSD/I) activity during the post reproductive season. As well, E2 regulates FSHβ mRNA expression all over the year suggesting a down regulation process carried out by this steroid. The effect on LHβ mRNA is dual, since during the reproductive season estradiol increases the expression of LHβ mRNA while in the non-reproductive season it has no effect. In conclusion, the effect of E2 on gonadotropins and testicular function is complex, not clearly understood and probably varies depending on the species. The aim of the current article is to review evidence on reproductive endocrinology and on the role of estradiol regulating reproduction in amphibians, with emphasis on the South American species Rhinella arenarum.
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Affiliation(s)
- María Florencia Scaia
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental, Buenos Aires, Argentina; Instituto de Biodiversidad y Biología Experimental y Aplicada (IBBEA - CONICET), Buenos Aires, Argentina.
| | - María Clara Volonteri
- Instituto de Diversidad y Evolución Austral (IDEAus - CONICET), Puerto Madryn, Chubut, Argentina
| | - Silvia Cristina Czuchlej
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental, Buenos Aires, Argentina.
| | - Nora Raquel Ceballos
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
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Rosenfeld CS, Denslow ND, Orlando EF, Gutierrez-Villagomez JM, Trudeau VL. Neuroendocrine disruption of organizational and activational hormone programming in poikilothermic vertebrates. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2017; 20:276-304. [PMID: 28895797 PMCID: PMC6174081 DOI: 10.1080/10937404.2017.1370083] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In vertebrates, sexual differentiation of the reproductive system and brain is tightly orchestrated by organizational and activational effects of endogenous hormones. In mammals and birds, the organizational period is typified by a surge of sex hormones during differentiation of specific neural circuits; whereas activational effects are dependent upon later increases in these same hormones at sexual maturation. Depending on the reproductive organ or brain region, initial programming events may be modulated by androgens or require conversion of androgens to estrogens. The prevailing notion based upon findings in mammalian models is that male brain is sculpted to undergo masculinization and defeminization. In absence of these responses, the female brain develops. While timing of organizational and activational events vary across taxa, there are shared features. Further, exposure of different animal models to environmental chemicals such as xenoestrogens such as bisphenol A-BPA and ethinylestradiol-EE2, gestagens, and thyroid hormone disruptors, broadly classified as neuroendocrine disrupting chemicals (NED), during these critical periods may result in similar alterations in brain structure, function, and consequently, behaviors. Organizational effects of neuroendocrine systems in mammals and birds appear to be permanent, whereas teleost fish neuroendocrine systems exhibit plasticity. While there are fewer NED studies in amphibians and reptiles, data suggest that NED disrupt normal organizational-activational effects of endogenous hormones, although it remains to be determined if these disturbances are reversible. The aim of this review is to examine how various environmental chemicals may interrupt normal organizational and activational events in poikilothermic vertebrates. By altering such processes, these chemicals may affect reproductive health of an animal and result in compromised populations and ecosystem-level effects.
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Affiliation(s)
- Cheryl S. Rosenfeld
- Department of Biomedical Sciences, University of Missouri, Columbia, MO, USA
- Thompson Center for Autism and Neurobehavioral Disorders, Columbia, MO, USA
- Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
| | - Nancy D. Denslow
- Department of Physiological Sciences, University of Florida, Gainesville, FL, USA
- Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL, USA
| | - Edward F. Orlando
- Department of Animal and Avian Sciences, University of Maryland, College Park, MD, USA
| | | | - Vance L. Trudeau
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
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Urbatzka R, Lorenz C, Wiedemann C, Lutz I, Kloas W. Steroid exposure during larval development of Xenopus laevis affects mRNA expression of the reproductive pituitary-gonadal axis in a sex- and stage-dependent manner. Comp Biochem Physiol C Toxicol Pharmacol 2014; 160:1-8. [PMID: 24239592 DOI: 10.1016/j.cbpc.2013.11.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 10/30/2013] [Accepted: 11/06/2013] [Indexed: 01/28/2023]
Abstract
Steroids are known to influence the reproductive pituitary-gonadal axis in adult amphibians. Here, we studied the effects of hormones on pituitary and gonadal mRNA expression during the development of Xenopus laevis. Tadpoles at NF 58 (prometamorphosis) and at NF 66 (freshly metamorphosed) were exposed for three days to 17β-estradiol (E2), tamoxifen (TAM), testosterone (T), dihydrotestosterone (DHT) at 10(-7)M, and flutamide (FLU) at 10(-6)M. In both genders at NF 58 and 66, T and DHT decreased luteinizing hormone beta (lhβ), but increased follicle stimulating hormone beta (fshβ), while FLU induced lhβ specifically in males. In the testis steroidogenic genes (p450 side chain cleavage enzyme, p450scc; steroid acute regulatory protein, star) at NF 58 showed a similar pattern as for lhβ, while the response at NF 66 was only partially present. In females, TAM induced lhβ at NF 58, while E2 decreased lhβ and increased fshβ at NF 66. In the ovaries, no alterations were observed for the steroidogenic genes. Summarizing, gonadotropic and steroidogenic mRNA expression may indicate control of androgen level during testis differentiation in male tadpoles at NF 58. In females the non-responsiveness of steroidogenic genes could be a sign of gonadal quiescence during pre-pubertal stages.
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Affiliation(s)
- Ralph Urbatzka
- CIIMAR, Centre of Marine and Environmental Research, Laboratory of Ecotoxicology, Genomics and Evolution, Rua dos Bragas 289, 4050-123 Porto, Portugal.
| | - Claudia Lorenz
- Department of Ecophysiology and Aquaculture, Leibniz-Institute for Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, 12587 Berlin, Germany
| | - Caterina Wiedemann
- Reproduction Biology, Leibniz-Institute for Zoo and Wildlife Research, PF 601103, 10252 Berlin, Germany
| | - Ilka Lutz
- Department of Ecophysiology and Aquaculture, Leibniz-Institute for Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, 12587 Berlin, Germany
| | - Werner Kloas
- Department of Ecophysiology and Aquaculture, Leibniz-Institute for Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, 12587 Berlin, Germany; Department of Endocrinology, Institute of Biology, Humboldt-University, Berlin, Germany
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Volonteri MC, Regueira E, Scaia MF, Ceballos NR. Characterization and seasonal changes in LHβ and FSHβ mRNA of Rhinella arenarum (Amphibia, Anura). Gen Comp Endocrinol 2013; 187:95-103. [PMID: 23619187 DOI: 10.1016/j.ygcen.2013.03.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 03/13/2013] [Accepted: 03/17/2013] [Indexed: 11/25/2022]
Abstract
In anurans, two types of gonadotropins were described in several species of Ranidae and Pipidae families but only in one of the Bufonidae family. Rhinella arenarum is a bufonid that have the lowest concentration of plasma androgens during the breeding. The objective of this paper was to characterize the cDNA sequence of β subunit of LH and FSH from toad pituitary and study seasonal variation in gonadotropins mRNA using quantitative real-time RT-PCR. The LHβ cDNA is a 636 bp sequence containing an open reading frame (ORF), 45 bp of 5'-untranslated region (UTR) and 174 bp of 3'-UTR. The ORF encodes for a signal peptide of 26 amino acids and a mature protein of 113 amino acids with one N-glycosylation site at the 34th position. The FSHβ cDNA sequence is a 535 bp fragment containing an ORF, 8 bp of 5'-UTR and 152 bp of 3'-UTR. The ORF encodes for a signal peptide of 20 amino acids and a mature protein of 104 amino acids with two N-glycosylation sites at 25th and 42nd positions. Multiple alignments of aminoacid deduced sequences of LHβ and FSHβ (teleosts, amphibians, birds, mammals) showed that all the tetrapods studied conserve 12 cysteins and one (LH) or two (FSH) N-Glycosylation sites. LHβ is closer to teleosts than to mammals and birds while FSHβ is closer to mammals. The analysis of seasonal changes in LHβ and FSHβ mRNA indicates that transcript levels have seasonal variations and that the profile of androgens is opposite to that of the gonadotropins mRNA.
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Affiliation(s)
- M Clara Volonteri
- Laboratorio de Endocrinología Comparada, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina.
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Kanda S, Okubo K, Oka Y. Differential regulation of the luteinizing hormone genes in teleosts and tetrapods due to their distinct genomic environments--insights into gonadotropin beta subunit evolution. Gen Comp Endocrinol 2011; 173:253-8. [PMID: 21663743 DOI: 10.1016/j.ygcen.2011.05.015] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Revised: 05/16/2011] [Accepted: 05/24/2011] [Indexed: 11/16/2022]
Abstract
The pituitary gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH), are essential for the control of vertebrate reproduction. Although the molecular structures of these two hormones are well conserved from teleosts to mammals, some studies report differences in their regulatory mechanisms of gene expression between teleosts and tetrapods. In the present study, we examined the molecular evolution of the gonadotropin gene loci in vertebrates and found that there is a syntenic conservation among the teleost fshb and tetrapod fshb and lhb loci. However, the teleost lhb locus has no syntenic homology to either tetrapod lhb or teleost fshb; this fact suggests that an extensive genome-wide rearrangement of the lhb locus, caused by an accelerated genome evolution speed after the third round of genome-wide duplication, occurred in the teleost lineage. We subsequently demonstrated by double labeling in situ hybridization using a teleost medaka that the fshb and lhb genes in teleosts are expressed in completely separate cellular populations in the pituitary, which is different in tetrapods. Furthermore, the expression analysis in ovariectomized and steroid-treated medaka revealed that, under breeding conditions, the expression of the medaka LHβ was down-regulated by ovariectomy and recovered by treatment with gonadal steroids; this result is also completely opposite in mammals, where the steroids have negative-feedback effects on LHβ expression. We suggest that these differences between teleosts and mammals in the cellular expression pattern and dynamic expressional changes of the lhb gene are the result of the drastic changes in the genomic environment of the lhb gene that occurred early in teleost evolution.
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Affiliation(s)
- Shinji Kanda
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan.
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Suda M, Kodama M, Oshima Y, Yamamoto K, Nakamura Y, Tanaka S, Kikuyama S, Nakamura M. Up-regulation of FSHR expression during gonadal sex determination in the frog Rana rugosa. Gen Comp Endocrinol 2011; 172:475-86. [PMID: 21521644 DOI: 10.1016/j.ygcen.2011.04.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Revised: 04/06/2011] [Accepted: 04/10/2011] [Indexed: 11/27/2022]
Abstract
In vertebrates, gonadal production of steroid hormones is regulated by follicle-stimulating hormone (FSH) and luteinizing hormone (LH) via their receptors designated FSHR and LHR, respectively. We have shown recently that steroid hormones are synthesized in the differentiating gonad of tadpoles during sex determination in the frog Rana rugosa. To elucidate the role of gonadotropins (GTHs) and their receptors in the production of gonadal steroid hormones during sex determination, we isolated the full-length FSHβ, LHβ, FSHR and LHR cDNAs from R. rugosa and determined gonadal expression of FSHR (FSH receptor) and LHR (LH receptor) as well as brain expression of FSHβ and LHβ during sex determination in this species. The molecular structures of these four glycoproteins are conserved among different classes of vertebrates. FSHβ expression was observed at similar levels in the whole brain (including the pituitary) of tadpoles, but it showed no sexual dimorphism during gonadal sex determination. By contrast, LHβ mRNA was undetectable in the whole brain of tadpoles. FSHβ-immunopositive cells were observed in the pituitary of female tadpoles with a differentiating gonad. Furthermore, FSHR expression was significantly higher in the gonad of female tadpoles during sex determination than in that of males, whereas LHR was expressed at similar levels in males and females. The results collectively suggest that FSHR, probably in conjunction with FSH, is involved in the steroid-hormone production during female-sex determination in R. rugosa.
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MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Brain/metabolism
- Cloning, Molecular
- DNA, Complementary/metabolism
- Follicle Stimulating Hormone, beta Subunit/chemistry
- Follicle Stimulating Hormone, beta Subunit/genetics
- Follicle Stimulating Hormone, beta Subunit/metabolism
- Luteinizing Hormone, beta Subunit/chemistry
- Luteinizing Hormone, beta Subunit/genetics
- Luteinizing Hormone, beta Subunit/metabolism
- Molecular Sequence Data
- RNA, Messenger/metabolism
- Ranidae/genetics
- Ranidae/metabolism
- Ranidae/physiology
- Receptors, FSH/chemistry
- Receptors, FSH/genetics
- Receptors, FSH/metabolism
- Receptors, LH/chemistry
- Receptors, LH/genetics
- Receptors, LH/metabolism
- Sequence Alignment
- Sex Characteristics
- Sex Determination Processes/genetics
- Sex Factors
- Up-Regulation
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Affiliation(s)
- Mari Suda
- Department of Biology, Faculty of Education and Integrated Arts and Sciences, Waseda University, Tokyo, Japan
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Urbatzka R, Lorenz C, Lutz I, Kloas W. Expression profiles of LHbeta, FSHbeta and their gonadal receptor mRNAs during sexual differentiation of Xenopus laevis tadpoles. Gen Comp Endocrinol 2010; 168:239-44. [PMID: 20171219 DOI: 10.1016/j.ygcen.2010.02.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Revised: 02/08/2010] [Accepted: 02/12/2010] [Indexed: 02/04/2023]
Abstract
The gonadotropins, luteinising hormone (LH) and follicle stimulating hormone (FSH), are important hormones regulating reproductive biology in vertebrates, especially the processes of steroidogenesis and gamete maturation. Despite the role of gonadotropins during the reproductive cycle in amphibians is well established, much less is known about the functional maturation of the hypothalamus-pituitary-gonad axis during larval development. Therefore, the present study aimed to analyze the expression profiles of hypophyseal LHbeta and FSHbeta mRNA and of their corresponding gonadal receptors (LH-R, FSH-R) in Xenopus laevis tadpoles during their ontogeny and sexual differentiation. The first significant elevation of LHbeta and FSHbeta mRNA was observed at late premetamorphosis. A clear raise of LHbeta mRNA was present during prometamorphic stages especially in males, while the LH-R only slowly increased during ontogeny with highest levels during metamorphic climax. In contrast, FSHbeta mRNA expression only slightly increased during ontogeny, however in both sexes the FSH-R mRNA was considerably elevated at prometamorphosis and further at metamorphic climax. Our results suggest that LHbeta and LH-R mRNA expression might be involved in initial maturation events of gametes, at least in males, while the gradually increase of FSH-R mRNA coincided with the advancing process of gamete maturation in both sexes. The present study provides for the first time evidence based on expression of gonadotropins and their corresponding gonadal receptors that the hypothalamus-pituitary-gonad axis evolves already at early stages of ontogeny and sexual differentiation in amphibians.
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Affiliation(s)
- R Urbatzka
- Department of Ecophysiology and Aquaculture, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, IGB, Mueggelseedamm 301, 12587 Berlin, Germany.
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Urbatzka R, Lutz I, Opitz R, Kloas W. Luteinizing hormone, follicle stimulating hormone, and gonadotropin releasing hormone mRNA expression of Xenopus laevis in response to endocrine disrupting compounds affecting reproductive biology. Gen Comp Endocrinol 2006; 146:119-25. [PMID: 16330033 DOI: 10.1016/j.ygcen.2005.10.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2005] [Revised: 10/12/2005] [Accepted: 10/16/2005] [Indexed: 11/27/2022]
Abstract
Environmental pollutants can interfere with the endocrine system of a variety of animals and are suggested to contribute to the worldwide decline of amphibians. In this study, the effects of endocrine disrupting compounds (EDC) on the hypothalamus-pituitary-gonad axis, regulating reproduction, were investigated in Xenopus laevis by determining their potential impact on gene expression of gonadotropin releasing hormone (GnRH), luteinizing hormone beta-subunit (LHbeta) and follicle-stimulating hormone beta-subunit (FSHbeta) in brain and pituitary using semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). One environmental sample and four model compounds, ethinylestradiol (EE2), tamoxifen (TAM), methyldihydrotestosterone (MDHT), and flutamide (FLU), corresponding to (anti)estrogenic and (anti)androgenic modes of action were used at 10(-8)M during a four weeks exposure of adults of both sexes. In general, males had a higher LHbeta mRNA level compared to females, while the mRNA expression of FSHbeta and GnRH did not differ between both sexes. EE2 and MDHT treatment decreased LHbeta mRNA expression in the brain of male X. laevis, while only EE2 but not MDHT reduced LHbeta mRNA in females indicating classical negative feed-back mechanisms on hypophyseal gonadotropin expression. TAM increased LHbeta mRNA and FSHbeta mRNA expression in female X. laevis while none of the other treatments showed an effect on FSHbeta mRNA expression. GnRH expression was not changed by any treatment and exposure of X. laevis to Lambro river water had no significant effect on any of the genes examined. It is reported for the first time in amphibians that gonadotropin mRNA expression is differentially regulated by (anti)estrogenic and (anti)androgenic EDC and that gender-specific patterns of gene expression exist.
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Affiliation(s)
- R Urbatzka
- Department of Inland Fisheries, Leibniz-Institute of Freshwater Biology and Inland Fisheries, Müggelseedamm 310, 12587 Berlin, Germany.
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Akgün-Dar K, Erensoy N, Yilmazer S. Immunocytochemical detection of effects of TRH and T4 on prolactin- and TSH-producing cells in the pituitary gland of Rana ridibunda. Acta Histochem 2004; 106:315-23. [PMID: 15350814 DOI: 10.1016/j.acthis.2004.05.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2003] [Revised: 05/04/2004] [Accepted: 05/04/2004] [Indexed: 11/24/2022]
Abstract
Effects of synthetic thyrotropin-releasing hormone (TRH) and various doses of thyroxin (T4) on prolactin (PRL)-producing cells and thyrotropic cells in the pituitary were investigated in adult male and female Rana ridibunda frogs. Animals were given 200 microg TRH once a week for 4 weeks and 0.2-0.5 mg T4 during 3 days per week for a period of 2 weeks by injections in the groin. PRL-producing cells and thyrotropic cells were identified with light microscopical and electron microscopical immunocytochemical methods, using rabbit anti-PRL and rabbit anti-thyroid stimulating hormone (TSH) as primary antibodies. TRH caused cytological changes in both cell types, which were consistent with increased synthesis and release of both PRL and TSH. Treatment with 0.5 mg T4 activated both cell types less than TRH treatment did, whereas 0.2 and 0.4 mg T4 caused inactivation of both cell types. In conclusion, mammalian TRH is effective on both types of frog pituitary cells. Our study suggests that T4 has a positive rather than a negative effect when concentrations above a certain threshold are given.
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Affiliation(s)
- Kadriye Akgün-Dar
- Istanbul University, Faculty of Science, Department of Biology, Zoology Section, Vezneciler, 34459 Istanbul, Turkey.
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Ferrandino I, Santanello D, Riccio T, Grimaldi MC. An immunohistochemical study of hypophysis inAnguis fragilis(Reptilia, Anguidae). ACTA ACUST UNITED AC 2004. [DOI: 10.1080/11250000409356612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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13
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Okada Y, Fujii Y, Moore JP, Winters SJ. Androgen receptors in gonadotrophs in pituitary cultures from adult male monkeys and rats. Endocrinology 2003; 144:267-73. [PMID: 12488354 DOI: 10.1210/en.2002-220770] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
There is substantial evidence demonstrating that the principal feedback action of androgens to decrease LH secretion in male primates, including man, is to slow the GnRH pulse generator, whereas in male rats androgens not only decrease GnRH but also suppress LH synthesis and secretion through a direct pituitary effect. Previous experiments in our laboratory revealed that testosterone (T) suppresses LH secretion and decreases alpha-subunit mRNA levels in male rat pituitary cell cultures perifused with pulses of GnRH but not in pituitary cells from adult male monkeys. In the present study, we sought to determine whether the lack of responsiveness of gonadotrophs to androgens in the primate is androgen receptor (AR) related. Primary cultures were prepared from the anterior pituitary glands of adult male monkeys and rats. Cells were identified as gonadotrophs if they were immunoreactive for LH-beta or FSH-beta. Of these cells in the monkey, 80% contained both gonadotropins, 17% contained only LH-beta, and 3% contained only FSH-beta. AR immunoreactivity (IR) was nuclear in 22% and 15%, respectively, of monkey and rat FSH-beta-positive cells in the absence of T. Following T treatment, nuclear AR IR was identified in 79% of monkey and 81% of rat gonadotrophs. T treatment similarly intensified AR IR in mouse gonadotroph alphaT3-1 and LbetaT2 cells and in monkey and rat fibroblasts. Single-cell RT-PCR confirmed coexpression of LH-beta and AR mRNA as well as LH-beta and GH mRNA in monkey gonadotrophs. Our data reveal that most monkey, as well as rat, gonadotrophs are AR-positive with nuclear localization in the presence of T. GH expression is not required for AR expression in gonadotrophs. We conclude that the failure of T to inhibit LH secretion and decrease alpha-subunit mRNA expression in the male primate is not due a disturbance in AR nuclear shuttling.
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MESH Headings
- Animals
- Cell Nucleus/chemistry
- Cells, Cultured
- Fluorescent Antibody Technique
- Follicle Stimulating Hormone, beta Subunit/analysis
- Gene Expression
- Growth Hormone/genetics
- Immunoenzyme Techniques
- Luteinizing Hormone/metabolism
- Luteinizing Hormone, beta Subunit/analysis
- Luteinizing Hormone, beta Subunit/genetics
- Macaca mulatta
- Male
- Pituitary Gland, Anterior/chemistry
- Pituitary Gland, Anterior/drug effects
- Pituitary Gland, Anterior/ultrastructure
- RNA, Messenger/analysis
- Rats
- Rats, Sprague-Dawley
- Receptors, Androgen/analysis
- Receptors, Androgen/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Testosterone/pharmacology
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Affiliation(s)
- Yohei Okada
- Division of Endocrinology and Metabolism, University of Louisville, Louisville, Kentucky 40202, USA
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14
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Puebla-Osorio N, Proudman JA, Compton AE, Clements KE, Decuypere E, Vandesande F, Berghman LR. FSH- and LH-cells originate as separate cell populations and at different embryonic stages in the chicken embryo. Gen Comp Endocrinol 2002; 127:242-8. [PMID: 12225765 DOI: 10.1016/s0016-6480(02)00054-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The histological distribution of gonadotrophs containing either LH or FSH, but not both gonadotropins, has been demonstrated before in the juvenile and adult chicken throughout the caudal and cephalic anterior pituitary lobes. In the present investigation, the distribution of FSH- and/or LH-containing gonadotrophs was further investigated in the chicken embryo by use of the same homologous antibodies as used in our earlier study. Fluorescent dual-labeling immunohistochemistry revealed that during embryogenesis LH and FSH reside exclusively in separate gonadotrophs, as has been described before in the post hatch bird. LH-immunoreactive cells were observed for the first time at day 9 of embryogenesis. This is as much as 4 days earlier than the FSH-immunoreactive cells, which appeared at day 13 of embryogenesis. Our results confirm that FSH- and LH-containing gonadotrophs are distributed throughout both lobes of the anterior pituitary. No conspicuous differences were observed between the sexes in any of the aspects investigated. The described situation is unique in that it seems to imply the existence of separate cell lineages for FSH- and LH-producing cells, as opposed to the single gonadotrope lineage described in all other species studied so far, with the exception of bovine. Our data indeed raise the question as to which signaling and/or transcription factors may cause the unique dichotomy observed in the chicken gonadotrophs.
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Affiliation(s)
- N Puebla-Osorio
- Department of Poultry Science, Texas A&M University, College Station 77843-2472 TX, USA.
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15
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Fiorentino M, Yamamoto K, Tanaka S, Pinelli C, D'Aniello B, Kikuyama S, Rastogi RK. Ontogenetic profile of FSH and LH in Rana esculenta. Gen Comp Endocrinol 1999; 116:114-21. [PMID: 10525367 DOI: 10.1006/gcen.1999.7313] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Circulating levels and pituitary content of FSH and LH were determined by specific radioimmunoassays in Rana esculenta starting a few days after hatching until the completion of metamorphosis. Both gonadotropins were found in the pituitary as well as in the blood plasma at all stages of development examined here. The plasma concentrations of FSH and LH were more or less uniform during pre- and prometamorphosis, but increased significantly at the onset of metamorphic climax. The plasma levels of FSH and LH remained high at the completion of metamorphosis. The pituitary content of FSH and LH was low in early premetamorphosis. It increased slightly through prometamorphosis and metamorphic climax, following which a highly significant increase occurred. Whereas plasma concentrations of FSH and LH were essentially similar within a single stage of development, the pituitary FSH content was severalfold higher than pituitary LH. The significance of these results is discussed in relation to the functional maturation of the brain-pituitary-gonadal axis in the frog.
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Affiliation(s)
- M Fiorentino
- Dipartimento di Zoologia, Università di Napoli Federico II, Naples, 80134, Italy
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16
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Proudman JA, Vandesande F, Berghman LR. Immunohistochemical evidence that follicle-stimulating hormone and luteinizing hormone reside in separate cells in the chicken pituitary. Biol Reprod 1999; 60:1324-8. [PMID: 10330088 DOI: 10.1095/biolreprod60.6.1324] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
As is the case in other tetrapod species, the chicken gonadotropins LH and FSH consist of a common alpha subunit and a hormone-specific beta subunit. Gonadotrophs containing LH were shown earlier to be distributed throughout both the caudal and cephalic lobes of the chicken anterior pituitary, but the cellular distribution of FSH in avian species is still uncertain. The purpose of this study was to determine the cellular distribution of FSH-containing chicken gonadotrophs by use of FSH-specific monoclonal antibodies (mAbs). Three new mAbs toward chicken FSH were proven hormone specific by immunodetection of purified hormones on dot blots and by dual-label immunohistochemistry (IHC) on sagittal sections of chicken pituitaries. A rabbit antibody was used to detect chicken LH. Results showed that LH-containing gonadotrophs were densely distributed throughout the anterior pituitary, whereas gonadotrophs containing FSH were much less numerous; in addition, while also present in both lobes, FSH-positive cells were largely absent from the outer margin of the gland. Dual-label IHC revealed that LH and FSH reside almost exclusively in separate gonadotrophs. The identity of FSH-containing cells was further confirmed through use of an antibody to the chicken alpha subunit, which showed that FSH immunoreactivity was always colocalized with the alpha subunit. Our results suggest the possibility that production and secretion of LH and FSH may be regulated differently in chickens than in most other species studied to date.
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Affiliation(s)
- J A Proudman
- Germplasm and Gamete Physiology Laboratory, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland 20705, USA.
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Pearson AK, Hayes TB, Licht P. Immunochemical identification of thyrotropes and gonadotropes in the pars distalis and pars tuberalis of the toad (Bufo boreas) with reference to ontogenic changes. Gen Comp Endocrinol 1998; 111:83-94. [PMID: 9653025 DOI: 10.1006/gcen.1998.7091] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Morphologically distinct secretory cells in the pituitary pars distalis and pars tuberalis of larval and adult toads (Bufo boreas) immunoreactive cells in the pars distalis. Thyrotropin immunoactivity appears in pars tuberalis and pars distalis before gonadotropin immunoreactivity during early development. Antisera which distinguish gonadotropes (stained with human and sea turtle LH beta) and thyrotropes (stained with human TSH beta) as separate cell types in the pars distalis of the adult toad immunoreact with the same single type of cell in the pars distalis of the tadpole up through metamorphosis, suggesting the existence of a single pluripotent, glycoprotein-producing precursor cell early in development. Gonadotropin antisera do not react with the pars tuberalis in tadpoles or adults.
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Affiliation(s)
- A K Pearson
- Museum of Vertebrate Zoology, University of California, Berkley 94720, USA
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Vallarino M, Mathieu M, D'Aniello B, Rastogi RK. Distribution of somatostatin-like immunoreactivity in the brain of the frog, Rana esculenta, during development. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1998; 106:13-23. [PMID: 9554935 DOI: 10.1016/s0165-3806(97)00162-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The anatomical distribution of somatostatin-like immunoreactivity in the central nervous system of the frog, Rana esculenta, during development and in juvenile specimens was investigated by indirect immunofluorescence. Soon after hatching, at stages II-III, somatostatin-like immunoreactive structures were found in the preoptic-median eminence complex. In stage VI tadpoles, new groups of immunopositive perikarya and nerve fibers appeared in the diencephalon, within the ventral infundibular nucleus and in the ventral area of the thalamus, as well as in the medial pallium. In stages XII-XIV of development, immunopositive perikarya were also present in the dorsal infundibular nucleus of the hypothalamus and ventrolateral area of the thalamus. A small group of somatostatin-like immunoreactive neurons appeared in the posteroventral nucleus of the rhombencephalon. However, these neurons were not seen in later stages of development. Tadpoles in stages XVIII, XXI-XXII and in juveniles were characterized by a wider distribution of immunoreactive cell bodies and fibers in the pallium. New groups of immunoreactive neurons were found in the dorsal and lateral pallium. The presence of positive perikarya in the lateral pallium is a transient expression found only in these stages. The organization of the somatostatinergic system was most complex during the metamorphic climax, with the appearance of positive cell bodies in the posterocentralis area of the thalamus, and in juvenile animals with the presence of perikarya in the ventral part of the medial pallium and within the central grey rhombencephali. In contrast to the adult frog, somatostatin neurons were not observed in the mesencephalon of tadpoles and juveniles.
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Affiliation(s)
- M Vallarino
- Istituto di Anatomia Comparata, Università di Genova, Italy
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