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Reproductive phenology of neotropical leptodactylid frogs (genera Physalaemus and Pseudopaludicola): Integrating gametogenic cycle, sexual maturity and age. ZOOL ANZ 2022. [DOI: 10.1016/j.jcz.2022.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Dias AB, de Oliveira SA, Cerri PS, Sasso-Cerri E. Bilateral asymmetry in bullfrog testes and fat bodies: correlations with steroidogenic activity, mast cells number and structural proteins. Acta Histochem 2022; 124:151873. [PMID: 35287007 DOI: 10.1016/j.acthis.2022.151873] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 03/02/2022] [Accepted: 03/03/2022] [Indexed: 11/16/2022]
Abstract
In seasonal breeders, such as amphibians, testicular functions depend on complex processes that change according to seasonality, including Leydig cell (LC) differentiation and lipid-dependent steroidogenesis, extracellular proteins remodeling and actin-dependent cellular dynamics. Speculating that fat bodies (FB) could support some of these processes in L. catesbeianus, we evaluated bilaterally the FB weights, correlating them to testicular parameters such as weight, testosterone (T) immunoexpression, mast cells (MC) number, vascularization and structural proteins. In an attempt to better understand the testicular asymmetry in amphibians, correlations between these different testicular parameters were also established. Right testes (RT), left testes (LT) and associated FB of bullfrogs were weighed, and testes were processed for light and transmission electron microscopy. Collagen content (COL) and MC number were quantified. T and actin immunoexpressions and vascular areas were measured. Statistical analyses and Pearson's correlation were performed. The LT and its associated FB were heavier than the right ones, and showed intense T and actin immunoexpressions, numerous lipid-rich LC, and greater MC number, COL and vascularization than the RT. Positive correlations were detected between: a) FB and testis weights, b) T immunoexpression and testis and FB weights, c) T and actin immunoexpressions and COL. Otherwise, MC number was inversely correlated to T immunoexpression and COL. In right and left sides, the proportional correlation between T immunoexpression and FB weight suggests that FB-stored lipid amount depends on the steroidogenic demand of its associated testis. Thus, the asymmetry in the testes and FB may be associated, at least in part, to the LC steroidogenic activity, which tends to be more intense in LT than in RT. The results also point to a role of COL and mast cells in the LC differentiation and steroidogenesis. Actin was also greater in LT and correlated with T immunoexpression, indicating that the amount of this structural protein depends on androgenic control. Therefore, the testicular asymmetry in bullfrogs seems to be associated to different morphofunctional processes occurring, bilaterally, at different intensities. In this case, there is a tendency of LT, in association with its FB, to be more active than RT. The findings highlight the FB-testis interplay for the comprehension of reproduction in amphibians.
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Affiliation(s)
- Andressa Baggio Dias
- São Paulo State University (Unesp), School of Dentistry, Department of Morphology, Genetics, Orthodontics and Pediatric Dentistry, Araraquara, Brazil
| | | | - Paulo Sérgio Cerri
- São Paulo State University (Unesp), School of Dentistry, Department of Morphology, Genetics, Orthodontics and Pediatric Dentistry, Araraquara, Brazil
| | - Estela Sasso-Cerri
- São Paulo State University (Unesp), School of Dentistry, Department of Morphology, Genetics, Orthodontics and Pediatric Dentistry, Araraquara, Brazil.
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Bordin RO, Dos Santos Fernandes CE, Franco-Belussi L, Ribeiro Farias Leão T, Sanabria M. Sperm morphology and testicular histology of the polyandric species Leptodactylus podicipinus (Anura: Leptodactylidae) from an urban environment. Anat Rec (Hoboken) 2022; 305:3532-3542. [PMID: 35365960 DOI: 10.1002/ar.24928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 03/15/2022] [Accepted: 03/15/2022] [Indexed: 11/11/2022]
Abstract
Anurans have a high reproductive diversity, which is closely associated with testicular dynamics and sperm production. This variety in reproduction is modulated by the sexual characteristics of reproductive strategies, such as polyandry. Leptodactylus podicipinus has high reproductive plasticity, wide geographical distribution, and polyandric behavior. Although aspects of the testes and sperm of this species are known, knowledge about the relationship between these aspects and reproductive investment is scarce. The present study evaluated the morphological characteristics of the testes and sperm in an urban environment. We used 11 sexually mature males from the city of Campo Grande, Mato Grosso do Sul, Brazil. The specimens were obtained from night excursions between April and September; the months that constitute the post-rainy season. The biometric data (snout-vent length, testes, and body mass) were associated with sperm parameters (length of the spermatozoon head and tail). Stereological analyses of sperm morphology and the testes were performed. The results showed correlations between testis mass and spermatozoon length, which were positively related to head length and negatively related to tail length. The locular area and tail length were also negatively correlated. The percentage of normal spermatozoa was 97%; however, some sperm heads and tails exhibited different morphologies from the pattern described for the species. The germinative structure comprised more than 50% of the locular area composed of spermatozoa. The results of this study contribute to the knowledge of aspects related to the reproductive biology of L. podicipinus obtained from an urban environment.
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Affiliation(s)
- Rafael Oliveira Bordin
- Programa de pós graduação em Biologia Animal, Universidade Federal de Mato Grosso do Sul, 79070-900, Campo Grande, MS, Brasil
| | - Carlos Eurico Dos Santos Fernandes
- Laboratório de Patologia Experimental (LAPEx), Instituto de Biociências, Universidade Federal de Mato Grosso do Sul, Campo Grande, Brasil
| | - Lilian Franco-Belussi
- Laboratório de Patologia Experimental (LAPEx), Instituto de Biociências, Universidade Federal de Mato Grosso do Sul, Campo Grande, Brasil
| | - Taynara Ribeiro Farias Leão
- Programa de pós graduação em Biodiversidade, Universidade Estadual Paulista, São José do Rio Preto, SP, Brasil
| | - Marciana Sanabria
- Instituto de Biociências, Universidade Federal de Mato Grosso do Sul, 79070-900, Campo Grande, Brasil
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Alaei R, Pesarakloo A, Najibzadeh M, Mirkamali SJ. Life-history traits and the first demographic data of Iranian population of the West Asian Lemon-Yellow Tree Frog, Hyla savignyi (Audouin, 1827). ACTA ZOOL ACAD SCI H 2021. [DOI: 10.17109/azh.67.3.247.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The life-history of an organism consists of its lifetime pattern of growth, development, storage, age, and reproduction. In this study, some life-history traits of Hyla savignyi were studied in populations from different parts of Iran. The microscopic and macroscopic analysis showed that testicular activity in H. savignyi is potentially continuous, reaching its peak level in April. Metamorphosis was completed in approximately 102 days after egg deposition, and body size at metamorphosis was 10 mm. Significant sexual size dimorphism was present in all populations, and a larger female asymptotic body size was observed (43.07 mm for females vs 41.16 mm for males). The adult survival rate (S) and life expectancy (ESP) were the same for both sexes (S = 0.73 and ESP = 4.2 years). Age and body size were positively correlated with each other for both females and males. Maximum longevity was recorded to be six years in both females and males, and ages of sexual maturity were estimated to be two or three years in breeding individuals. The adult sample age ranged from two to six years (mean age of females: 4.40±0.68 years; males: 3.63±0.13 years). Our data confirm the general patterns of body size variation and mean age in anurans and show that females are larger than males and live longer.
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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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Luz JS, Caneguim BH, Baggio A, Santoni MM, Helbing CC, Valentini SR, Sasso-Cerri E, Oliveira CC. Differential expression of RNA exosome subunits in the amphibian Lithobates catesbeianus during reproductive and non-reproductive periods. BMC Res Notes 2019; 12:46. [PMID: 30665462 PMCID: PMC6341637 DOI: 10.1186/s13104-019-4077-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 01/11/2019] [Indexed: 11/20/2022] Open
Abstract
Objective The RNA exosome is an evolutionarily conserved 3′–5′ exoribonucleolytic protein complex involved in processing and degradation of different classes of nuclear and cytoplasmic RNAs, and, therefore, important for the posttranscriptional control of gene expression. Despite the extensive in vivo functional studies and the structural data on the RNA exosome, few studies have been performed on the localization and expression of exosome subunits during gametogenesis, process during which gene expression is largely controlled at the posttranscriptional level. Results We report the identification of exosome subunits in Lithobates catesbeianus and analysis of the differential subcellular localization of RNA exosome core and catalytic subunits in testis cells. In addition, we show seasonal differences in the expression levels of four exosome subunits in different organs. In addition to being part of the RNA exosome complex, its subunits might participate independently of the complex in the control of gene expression during seasonal variation in bullfrog tissues. These results may be relevant for other eukaryotic species. Electronic supplementary material The online version of this article (10.1186/s13104-019-4077-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- J S Luz
- School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara, Brazil
| | - B H Caneguim
- Department of Morphology and Genetics, Federal University of São Paulo (UNIFESP), São Paulo, Brazil.,Federal University of Triângulo Mineiro (UFTM)-Iturama University Campus (UFTM-CIT), Iturama, Brazil
| | - A Baggio
- School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara, Brazil
| | - M M Santoni
- School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara, Brazil
| | - C C Helbing
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - S R Valentini
- School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara, Brazil
| | - E Sasso-Cerri
- Department of Morphology, Dental School of São Paulo State University, Araraquara, Brazil
| | - C C Oliveira
- Department of Biochemistry, Chemistry Institute, University of São Paulo, São Paulo, Brazil.
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Borah BK, Renthlei Z, Trivedi AK. Seasonality in terai tree frog (Polypedates teraiensis): Role of light and temperature in regulation of seasonal breeding. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2018; 191:44-51. [PMID: 30580184 DOI: 10.1016/j.jphotobiol.2018.12.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 11/17/2018] [Accepted: 12/10/2018] [Indexed: 11/19/2022]
Abstract
Seasonality is represented as an initiation-termination-reinitiation of any physiological processes. Photoperiod is the most predictable environmental cue which organism use to time their daily physiology and seasonal functions. In natural light environmental conditions, day and night components change in terms of duration, intensity and spectrum of light available. In many vertebrate species, daytime light intensity and spectrum of light play a critical role in gonadal recrudescence-regression cycle. In tropical conditions, many amphibian species show a clear relationship between reproduction and seasonal distribution of rainfall. In temperate conditions, reproduction is usually centered during spring and summer seasons when environmental conditions are favorable. Poikilotherms are highly sensitive to change in environmental temperature and their physiology and metabolic activities depend on environmental temperature. How environmental factors (light and temperature) influence, the reproduction of terai tree frog (Polypedates teraiensis) is not known. We hypothesized that light acts as a proximate factor but the temperature is the ultimate factor for reproduction of terai tree frog. Three experiments were performed. In experiment one, we studied the annual reproductive cycle under natural environmental conditions. Beginning from the month of March till October 2016, we procured adult frogs (male and female) in the middle of each month. Monthly observations were recorded for body weight and gonadal weight and GSI was calculated. We found the annual change in body mass, gonadal weight and GSI in both male and female with high gonadal weight and GSI values from March to June. These results suggest that terai tree frog is seasonal breeders, and their breeding corresponds with long days. In experiment two we addressed the effects of light duration, light intensity and light spectrum on gonadal growth regression cycle. We observed that long days promote gonadal growth regression cycle. However, after achieving critical daylength there is no additive effect of light duration. Further, light intensity and spectrum have limited role in gonadal growth regression cycle of this species. In experiment three we tested the role of temperature on body weight and testicular growth under stimulatory photoperiod (12 L:12D). Group one was exposed to high temperature (34 ± 2 °C), while group two was exposed to low temperature (22 ± 2 °C). We found that low temperature promotes testicular recrudescence under laboratory conditions. Altogether our study suggests both photoperiod and temperature are involved in the regulation of seasonal breeding in tree frog. Findings from the above study could be used for captive breeding of amphibians and may be helpful in amphibian conservation programmes.
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Affiliation(s)
| | | | - Amit Kumar Trivedi
- Department of Zoology, Mizoram University, Aizawl, Mizoram 796004, India.
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Ockleford C, Adriaanse P, Berny P, Brock T, Duquesne S, Grilli S, Hernandez-Jerez AF, Bennekou SH, Klein M, Kuhl T, Laskowski R, Machera K, Pelkonen O, Pieper S, Stemmer M, Sundh I, Teodorovic I, Tiktak A, Topping CJ, Wolterink G, Aldrich A, Berg C, Ortiz-Santaliestra M, Weir S, Streissl F, Smith RH. Scientific Opinion on the state of the science on pesticide risk assessment for amphibians and reptiles. EFSA J 2018; 16:e05125. [PMID: 32625798 PMCID: PMC7009658 DOI: 10.2903/j.efsa.2018.5125] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Following a request from EFSA, the Panel on Plant Protection Products and their Residues developed an opinion on the science to support the potential development of a risk assessment scheme of plant protection products for amphibians and reptiles. The coverage of the risk to amphibians and reptiles by current risk assessments for other vertebrate groups was investigated. Available test methods and exposure models were reviewed with regard to their applicability to amphibians and reptiles. Proposals were made for specific protection goals aiming to protect important ecosystem services and taking into consideration the regulatory framework and existing protection goals for other vertebrates. Uncertainties, knowledge gaps and research needs were highlighted.
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Iruzubieta Villagra L, Ramos I, Cisint S, Crespo CA, Fernández SN. Electron microscopy observations on testis and spermatozoa of Leptodactylus chaquensis (Anura, Leptodactylidae). Micron 2018; 105:35-46. [DOI: 10.1016/j.micron.2017.11.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 10/23/2017] [Accepted: 11/15/2017] [Indexed: 01/26/2023]
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Kisserli O, Moudilou E, Exbrayat JM. Sexual cycle and seasonal expression of testosterone (T) in the testes of Sclerophrys mauritanica (Schlegel, 1841). AFR J HERPETOL 2017. [DOI: 10.1080/21564574.2017.1369170] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
Affiliation(s)
- Omar Kisserli
- Laboratoire de Biotechnologie, Environnement et Santé. Université Mohamed Seddik Benyahia-Jijel. BP. 98. Ouled Aïssa, Jijel (18000) –Algérie
| | - Elara Moudilou
- Université de Lyon, UMRS 449, Biologie Générale - Reproduction et Développement Comparé, Université Catholique de Lyon - EPHE/PSL, 10 place des archives, F-69288 Lyon Cedex 02, France
| | - Jean-Marie Exbrayat
- Université de Lyon, UMRS 449, Biologie Générale - Reproduction et Développement Comparé, Université Catholique de Lyon - EPHE/PSL, 10 place des archives, F-69288 Lyon Cedex 02, France
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Montezol M, Cassel M, Silva D, Ferreira A, Mehanna M. Gametogenesis and reproductive dynamics ofRhinella schneideri(Anura: Bufonidae): Influence of environmental and anthropogenic factors. ACTA ZOOL-STOCKHOLM 2017. [DOI: 10.1111/azo.12195] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Michel Montezol
- Biology Institute; State University of Campinas; São Paulo SP Brazil
| | - Mônica Cassel
- Department of Cell and Developmental Biology; Institute of Biomedical Sciences; University of São Paulo; São Paulo SP Brazil
| | - Débora Silva
- Biology Institute; State University of Campinas; São Paulo SP Brazil
| | - Adelina Ferreira
- Institute of Biosciences; Federal University of Mato Grosso; Mato Grosso Brazil
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Altitude underlies variation in the mating system, somatic condition, and investment in reproductive traits in male Asian grass frogs (Fejervarya limnocharis). Behav Ecol Sociobiol 2016. [DOI: 10.1007/s00265-016-2128-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Scaia MF, Czuchlej SC, Cervino N, Ceballos NR. Apoptosis, proliferation and presence of estradiol receptors in the testes and Bidder's organ of the toadRhinella arenarum(Amphibia, Anura). J Morphol 2015; 277:412-23. [DOI: 10.1002/jmor.20507] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 11/29/2015] [Accepted: 12/06/2015] [Indexed: 01/23/2023]
Affiliation(s)
- María Florencia Scaia
- 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
| | - Silvia Cristina Czuchlej
- 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
| | - Nadia Cervino
- 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
| | - Nora Raquel Ceballos
- 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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Scaia MF, Volonteri MC, Czuchlej SC, Ceballos NR. Effect of estradiol on apoptosis, proliferation and steroidogenic enzymes in the testes of the toad Rhinella arenarum (Amphibia, Anura). Gen Comp Endocrinol 2015; 221:244-54. [PMID: 25583585 DOI: 10.1016/j.ygcen.2014.12.016] [Citation(s) in RCA: 9] [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: 10/30/2014] [Revised: 12/22/2014] [Accepted: 12/26/2014] [Indexed: 12/18/2022]
Abstract
Estrogens inhibit androgen production and this negative action on amphibian steroidogenesis could be related to the regulation of steroidogenic enzymes. Estrogens are also involved in the regulation of amphibian spermatogenesis by controlling testicular apoptosis and spermatogonial proliferation. The Bidder's organ (BO) is a structure characteristic from the Bufonidae family and in adult males of Rhinella arenarum it is one of the main sources of plasma estradiol (E2). The purpose of this study is to analyze the effect of E2 on testicular steroidogenic enzymes, apoptosis and proliferation in the toad R. arenarum. For this purpose, testicular fragments were treated during 24h with or without 2 or 20nM of E2. After treatments, the activities of cytochrome P450 17α-hydroxylase-C17-20 lyase (CypP450c17) and 3β-hydroxysteroid dehydrogenase/isomerase (3β-HSD/I) were measured by the transformation of radioactive substrates into products, and CypP450c17 expression was determined by Western blot analysis. Apoptosis in testicular sections was detected with a commercial fluorescent kit based on TUNEL method, and proliferation was evaluated by BrdU incorporation. Results indicate that E2 has no effect on CypP450c17 protein levels or enzymatic activity, while it reduces 3β-HSD/I activity during the post reproductive season. Furthermore, although E2 has no effect on apoptosis during the pre and the post reproductive seasons, it stimulates testicular apoptosis during the reproductive season, mostly in spermatocytes. Finally, E2 has no effect on testicular proliferation all year long. Taken together, these results suggest that E2 is involved in the regulation of testicular steroidogenesis and spermatogenesis.
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Affiliation(s)
- María Florencia Scaia
- 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.
| | - María 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.
| | - Silvia Cristina Czuchlej
- 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.
| | - Nora Raquel Ceballos
- 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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Caneguim BH, da Luz JS, Valentini SR, Cerri PS, Sasso-Cerri E. Immunoexpression of aromatase and estrogen receptors β in stem spermatogonia of bullfrogs indicates a role of estrogen in the seasonal spermatogonial mitotic activity. Gen Comp Endocrinol 2013; 182:65-72. [PMID: 23247274 DOI: 10.1016/j.ygcen.2012.12.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 11/23/2012] [Accepted: 12/03/2012] [Indexed: 10/27/2022]
Abstract
Bullfrog stem spermatogonia, also named primordial germ cells (PGCs), show strong testosterone immunolabeling in winter, but no or weak testosterone immunoexpression in summer. Thus, the role of testosterone in these cells needs to be clarified. In this study, we proposed to evaluate whether PGCs express aromatase and estrogen receptors, and verify a possible role of estrogen in PGCs seasonal proliferation. Testes of male adult bullfrogs, collected in winter (WG) and summer (SG), were fixed and embedded in historesin, for quantitative analysis, or paraffin for immunohistochemistry (IHC). The number of haematoxylin/eosin stained PGCs/lobular area was obtained. Proliferating cell nuclear antigen (PCNA), aromatase, estrogen receptor β (ERβ) and PCNA/ERβ double immunolabeling were detected by IHC. The number of PCNA-positive PGCs and the histological score (HSCORE) of aromatase and ERβ immunolabeled PGCs were obtained. Although the number of PGCs increased significantly in WG, a high number of PCNA-positive PGCs was observed in summer. Moreover, aromatase and ERβ HSCORE was higher in SG than WG. The results indicate that PGCs express a seasonal proliferative activity; the low mitotic activity in winter is related to the maximal limit of germ cells which can be supported in the large lobules. In SG, the increased ERβ and aromatase HSCORE suggests that testosterone is converted into estrogen from winter to summer. Moreover, the parallelism between the high PGCs mitotic activity and ERβ immunoexpression suggest a participation of estrogen in the control of the PGCs seasonal proliferative activity which guarantee the formation of new germ cysts from summer to next autumn.
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Affiliation(s)
- Breno Henrique Caneguim
- Department of Morphology and Genetics, Federal University of São Paulo, UNIFESP, São Paulo, Brazil
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Abstract
SummaryThe organization and the histological characteristics of Leptodactylus chaquensis testis throughout the reproductive cycle were analyzed in the presented study. Gonads of adult males, processed with routine techniques for optical microscopy, revealed that during the reproductive period the seminiferous tubules were characterized by presentation of a large number of cysts, germ cells at the same maturation stage supported by Sertoli cells. All the germ line cells were also present in the postreproductive period and maintained their morphological characteristics. Primary spermatogonia were large-sized cells found isolated or in small groups. The rest of the cells of the germ line formed cysts. Secondary spermatogonia showed morphological characteristics similar to their predecessors, although they were smaller. Primary and secondary spermatocytes showed images of the different stages of the first and second meiotic division respectively. One finding was the presence of intercytoplasmic bridges between the secondary spermatocytes. Primary spermatids were rounded cells with an acrosomal vesicle associated with the nucleus and had cysts that were characterized by large intercellular spaces. Secondary spermatids were elongated cells with a well defined acrosome, which in the spermatozoa had the shape of an arrowhead. Another peculiar characteristic of this species was the fusion of the walls of the seminiferous tubule with the efferent duct that formed a path for spermatozoa during spermiation. The presence in the seminiferous tubules of all stages of the spermatogenic line during the two periods of the cycle studied indicated that Leptodactylus chaquensis had a potentially continuous reproductive cycle.
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Caneguim BH, Beltrame FL, da Luz JS, Valentini SR, Cerri PS, Sasso-Cerri E. Primordial germ cells (spermatogonial stem cells) of bullfrogs express sex hormone-binding globulin and steroid receptors during seasonal spermatogenesis. Cells Tissues Organs 2012; 197:136-44. [PMID: 22986369 DOI: 10.1159/000341517] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/29/2012] [Indexed: 11/19/2022] Open
Abstract
In vertebrate species, testosterone seems to inhibit spermatogonial differentiation and proliferation. However, this androgen can also be converted, via aromatase, into estrogen which stimulates spermatogonial differentiation and mitotic activity. During seasonal spermatogenesis of adult bullfrogs Lithobates catesbeianus, primordial germ cells (PGCs) show enhanced testosterone cytoplasm immunoexpression in winter; however, in summer, weak or no testosterone immunolabelling was observed. The aim of this study was to confirm if PGCs express stem cell markers - alkaline phosphatase (AP) activity and GFRα1 (glial-cell-line-derived neurotrophic factor) - and verify whether testosterone is maintained in these cells by androgen receptors (ARs) and/or sex hormone-binding globulin (SHBG) in winter. Furthermore, regarding the possibility that testosterone is converted into estrogen by PGCs in summer, the immunoexpression of estrogen receptor (ER)β was investigated. Bullfrog testes were collected in winter and in summer and were embedded in glycol methacrylate for morphological analyses or in paraffin for the histochemical detection of AP activity. GFRα1, AR, SHBG and ERβ expression were detected by Western blot and immunohistochemical analyses. The expression of AP activity and GFRα1 in the PGCs suggest that these cells are spermatogonial stem cells. In winter, the cytoplasmic immunoexpression of ARs and SHBG in the PGCs indicates that testosterone is maintained by these proteins in these cells. The cytoplasmic immunoexpression of ERβ, in summer, also points to an ER-mediated action of estrogen in PGCs. The results indicate a participation of testosterone and estrogen in the control of the primordial spermatogonia during the seasonal spermatogenesis of L. catesbeianus.
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Santos LRDS, Franco-Belussi L, Oliveira CD. Germ Cell Dynamics during the Annual Reproductive Cycle ofDendropsophus minutus(Anura: Hylidae). Zoolog Sci 2011; 28:840-4. [DOI: 10.2108/zsj.28.840] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Reitemeier S, Hänse M, Hahn A, Schmidt V, Steinbach-Sobiraj K, Krautwald-Junghanns ME, Einspanier A. Evaluating the reproductive status of the male budgerigar (Melopsittacus undulatus). Gen Comp Endocrinol 2011; 171:350-8. [PMID: 21377466 DOI: 10.1016/j.ygcen.2011.02.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2010] [Revised: 02/05/2011] [Accepted: 02/25/2011] [Indexed: 01/10/2023]
Abstract
Limited knowledge about male psittacine reproduction reduces the success of breeding programmes. Within the scope of fecundity assessment, classification of male sexual status is essential for effective conservation of the species. The aim of the present study was to investigate the testes of male budgerigars (Melopsittacus undulatus), as psittaciform model species to verify their reproductive status by morphological and immunocytochemical examination. Using light microscopy, gonadal samples were categorized resulting in three reproductive states (active, intermediate, non-active). Calculation of testes weights plus measurement of tubular and interstitial dimensions displayed significant (p ≤ 0.05) differences between all three reproductive stages. Lipids in the testicular tubules, analysed by Sudan black staining and fluorescence microscopy (DAPI(2) mode) were highly present in non-active status. Immunocytochemistry involved two different hydroxysteroid dehydrogenases (HSD), 3β-HSD and 17β-HSD-2, as markers for steroidogenesis, as well as steroid receptors for androgens (AR), oestrogen (ER) and progesterone (PR). Both HSDs and AR declined in non-active gonads compared to active and intermediate stages, with a positive signal in germ and somatic cells of testis and epididymis. ER and PR were detected in testicular and epididymal cells, similarly expressed in all three stages. The proliferation rate of germ cells in the testicular tubules, obtained by Ki67, differed significantly in active (38.67%), intermediate (32.40%) and non-active (6.01%) status. According to this morphological study, we have been able to establish markers for the reproductive staging of psittacine testes. This knowledge will be useful to deepen reproductive biology in budgerigars.
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Affiliation(s)
- Susanne Reitemeier
- Clinic for Birds and Reptiles, Veterinary Faculty, University of Leipzig, An den Tierkliniken 17, 04103 Leipzig, Germany.
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Simeó CG, Kurtz K, Chiva M, Ribes E, Rotllant G. Spermatogenesis of the spider crab Maja brachydactyla (Decapoda: Brachyura). J Morphol 2010; 271:394-406. [PMID: 19885918 DOI: 10.1002/jmor.10805] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This study describes spermatogenesis in a majid crab (Maja brachydactyla) using electron microscopy and reports the origin of the different organelles present in the spermatozoa. Spermatogenesis in M. brachydactyla follows the general pattern observed in other brachyuran species but with several peculiarities. Annulate lamellae have been reported in brachyuran spermatogenesis during the diplotene stage of first spermatocytes, the early and mid-spermatids. Unlike previous observations, a Golgi complex has been found in mid-spermatids and is involved in the development of the acrosome. The Golgi complex produces two types of vesicles: light vesicles and electron-dense vesicles. The light vesicles merge into the cytoplasm, giving rise to the proacrosomal vesicle. The electron-dense vesicles are implicated in the formation of an electron-dense granule, which later merges with the proacrosomal vesicle. In the late spermatid, the endoplasmic reticulum and the Golgi complex degenerate and form the structures-organelles complex found in the spermatozoa. At the end of spermatogenesis, the materials in the proacrosomal vesicle aggregate in a two-step process, forming the characteristic concentric three-layered structure of the spermatozoon acrosome. The newly formed spermatozoa from testis show the typical brachyuran morphology.
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Armstrong CG, Conte CE. Taxocenose de anuros (Amphibia: Anura) em uma área de Floresta Ombrófila Densa no Sul do Brasil. BIOTA NEOTROPICA 2010. [DOI: 10.1590/s1676-06032010000100003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A riqueza de espécies, o uso de habitat e a identificação das principais ameaças sobre uma taxocenose de anfíbios anuros foram determinadas ao longo de 19 meses, em uma localidade originalmente coberta de Floresta Ombrófila Densa no município de Morretes, Paraná, Brasil. Foram registradas 32 espécies de anuros pertencentes a 10 famílias. A anurofauna local apresenta 58% das espécies associadas à ambientes de área aberta e 42% associadas à ambientes florestais. Dentre todos os modos reprodutivos registrados, o modo tipo um - ovos e larvas exotróficas em habitats lênticos, foi o mais comum, especialmente em Hylidae. A atividade de desmatamento, que atualmente é umas das causas de maior efeito negativo sobre populações de anfíbios, ocorre a pelo menos 28 anos nessa região. Iniciativas de conservação e o manejo adequado da área são necessários para que a diversidade de anuros possa ser preservada.
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HUO S, XU Z, ZHANG X, ZHANG J, CUI S. Testicular Denervation in Prepuberty Rat Inhibits Seminiferous Tubule Development and Spermatogenesis. J Reprod Dev 2010; 56:370-8. [DOI: 10.1262/jrd.10-009n] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Shuying HUO
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University
- College of Animal Science and Technology, Hebei Agricultural University
| | - Zhihao XU
- School of Life Sciences, Lanzhou University
| | - Xiaoxin ZHANG
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University
| | - Jianfang ZHANG
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University
| | - Sheng CUI
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University
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Duration of spermatogenesis in the bullfrog (Lithobates catesbeianus). Theriogenology 2009; 72:894-901. [DOI: 10.1016/j.theriogenology.2009.06.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Revised: 05/27/2009] [Accepted: 06/03/2009] [Indexed: 11/20/2022]
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Caneguim BH, Cerri PS, Spolidório LC, Miraglia SM, Sasso-Cerri E. Structural alterations in the seminiferous tubules of rats treated with immunosuppressor tacrolimus. Reprod Biol Endocrinol 2009; 7:19. [PMID: 19243597 PMCID: PMC2660339 DOI: 10.1186/1477-7827-7-19] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2008] [Accepted: 02/25/2009] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND Tacrolimus (FK-506) is an immunosuppressant that binds to a specific immunophilin, resulting in the suppression of the cellular immune response during transplant rejection. Except for some alterations in the spermatozoa, testicular morphological alterations have not been described in rats treated with tacrolimus. In the present study, we purpose to evaluate if the treatment with tacrolimus at long term of follow-up interferes in the integrity of the seminiferous tubules. METHODS Rats aging 42-day-old received daily subcutaneous injections of 1 mg/kg/day of tacrolimus during 30 (T-30) and 60 (T-60) days; the rats from control groups (C-30 and C-60) received saline solution. The left testes were fixed in 4% formaldehyde and embedded in glycol methacrylate for morphological and morphometric analyses while right testes were fixed in Bouin's liquid and embedded in paraffin for detection of cell death by the TUNEL method. The epithelial and total tubular areas as well as the stages of the seminiferous epithelium and the number of spermatocytes, spermatids and Sertoli cells (SC) per tubule were obtained. RESULTS In the treated groups, seminiferous tubules irregularly outlined showed disarranged cellular layers and loss of germ cells probably due to cell death, which was revealed by TUNEL method. In addition to germ cells, structural alterations in the SC and folding of the peritubular tissue were usually observed. The morphometric results revealed significant decrease in the number of SC, spermatocytes, spermatids and significant reduction in the epithelial and total tubular areas. CONCLUSION Tacrolimus induces significant histopathological disorders in the seminiferous tubules, resulting in spermatogenic damage and reduction in the number of Sertoli cells. A careful evaluation of the peritubular components will be necessary to clarify if these alterations are related to the effect of FK-506 on the peritubular tissue.
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Affiliation(s)
- Breno H Caneguim
- Department of Morphology and Genetics, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - Paulo S Cerri
- Department of Morphology, Laboratory of Histology and Embryology, Dental School – São Paulo State University (UNESP), Araraquara, Brazil
| | - Luís C Spolidório
- Department of Physiology and Pathology, Dental School – São Paulo State University (UNESP), Araraquara, Brazil
| | - Sandra M Miraglia
- Department of Morphology and Genetics, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - Estela Sasso-Cerri
- Department of Morphology, Laboratory of Histology and Embryology, Dental School – São Paulo State University (UNESP), Araraquara, Brazil
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Kaptan E, Murathanoğlu O. Annual Morphological Cycles of Testis and Thumb Pad of the Male Frog (Rana ridibunda). Anat Rec (Hoboken) 2008; 291:1106-14. [DOI: 10.1002/ar.20723] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Santos LRDS, Oliveira CD. Morfometria testicular durante o ciclo reprodutivo de Dendropsophus minutus (Peters) (Anura, Hylidae). ACTA ACUST UNITED AC 2007. [DOI: 10.1590/s0101-81752007000100008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Este estudo descreve o ciclo reprodutivo de machos de Dendropsophus minutus (Peters, 1872) com base na análise da morfometria testicular e a correlação com parâmetros climáticos. Cinqüenta indivíduos foram coletados em São José do Rio Preto, São Paulo. Após as análises macroscópicas, os testículos foram encaminhados à rotina histológica, fixados com Bouin e incluídos em historesina. Cortes de 2 µm foram corados com azul de toluidina 1% e observados ao microscópio. Testículos de D. minutus são órgãos pequenos (comprimento 1,90 ± 0,13 mm), esbranquiçados, com forma oval e encontrados na cavidade abdominal. Estão localizados na extremidade cranial dos rins e apresentam assimetria quanto a sua posição. Estatisticamente não há variação intra-individual no comprimento e no peso dos testículos, bem como na área e diâmetro dos lóculos seminíferos. Quanto à histologia testicular, foi possível identificar ao longo do ano nos lóculos seminíferos, todos os tipos celulares da linhagem espermatogênica, caracterizando uma gametogênese contínua, corroborada por fatores ecológicos e comportamentais. Informações sobre a morfometria testicular e ciclo reprodutivo tem importante valor biológico para anuros de regiões neotropicais.
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Sasso-Cerri E, Cerri PS, Freymüller E, Miraglia SM. Apoptosis during the seasonal spermatogenic cycle of Rana catesbeiana. J Anat 2006; 209:21-9. [PMID: 16822266 PMCID: PMC2100304 DOI: 10.1111/j.1469-7580.2006.00582.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/14/2006] [Indexed: 11/29/2022] Open
Abstract
In the bullfrog Rana catesbeiana, testicular weight is constant throughout the year, but the volume densities of germinative and interstitial compartments undergo inverse changes from winter (non-breeding) to summer (breeding). The occurrence of apoptosis in the seminiferous lobules of bullfrogs was investigated in these two periods using sections stained with haematoxylin and eosin (H&E), the TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling) method and transmission electron microscopy. TUNEL-positive cells were observed in the seminiferous lobules, and ultrastructural morphological details confirmed the occurrence of cell death by apoptosis. In summer, the occurrence of several spermatogenic processes (in addition to spermiogenesis and spermiation), and then the overconsumption of Sertoli cell-derived pro-survival factors, could be responsible for the increased density of apoptotic cells. Alternatively, the low apoptotic frequency in winter could be related to the constant homeostasis in the germinative compartment given that most lobules are filled with primary spermatocytes. As volume densities of interstitial and germinative compartments undergo inverse seasonal variations through the year, the incidence of apoptosis (in summer) could play a part in controlling the spermatogenic process, maintaining the lobular size when interstitial tissue is maximally developed. In winter, the low apoptotic cell density leads to spermatogenic recrudescence and, thereby, the production of an adequate quantity of spermatozoa for the next breeding period. Thus, apoptosis may participate not only in the maintenance of spermatogenic homeostasis, but also in the cyclical control of the different spermatogenic processes according to seasonal changes of the testicular compartments as a whole.
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Affiliation(s)
- Estela Sasso-Cerri
- Department of Morphology, Dental School, São Paulo State University (UNESP), Araraquara, Brazil.
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Rosemblit C, Pozzi AG, Ceballos NR. Relationship between steroidogenesis and spermiation in Rana catesbeiana and Leptodactylus ocellatus. J Comp Physiol B 2006; 176:559-66. [PMID: 16552601 DOI: 10.1007/s00360-006-0078-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2005] [Revised: 01/26/2006] [Accepted: 02/01/2006] [Indexed: 10/24/2022]
Abstract
The present study employs an in vitro system to analyse the role of steroid hormones in hCG-induced spermiation in two species of anuran amphibian: Rana catesbeiana and Leptodactylus ocellatus. In vitro spermiation was induced with 10 IU hCG and the effect of different steroid-biosynthesis inhibitors was analysed. Cyanoketone (10(-5)M), an inhibitor of 3-oxo-4-ene steroid biosynthesis, did not block hCG-inducing activity even when biosynthesis of androgen was significantly reduced. These results clearly showed that, in both species, spermiation-inducing action of hCG does not depend on the biosynthesis of 3-oxo-4-ene steroids. Moreover, when combined inhibitors, aminoglutethimide (10(-5)M) plus cyanoketone (10(-5)M), were employed, spermiation evoked by hCG was not modified while hCG-induced androgen secretion significantly decreased. Additionally, none of the steroids used, progesterone, 17, 20 alpha-dihydroxy-4-pregnen-3-one, testosterone and 5 alpha-dihydrotestosterone, were able to induce spermiation in the absence of hCG, confirming that steroids are not involved in that process. In conclusion, as previously described in Bufo arenarum, in L. ocellatus and R. catesbeiana hCG-induced spermiation does not depend on steroid biosynthesis.
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Affiliation(s)
- Cinthia Rosemblit
- Laboratorio de Endocrinología Comparada and PRHOM-CONICET, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
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Sasso-Cerri E, Freymüller E, Miraglia SM. Testosterone-immunopositive primordial germ cells in the testis of the bullfrog, Rana catesbeiana. J Anat 2005; 206:519-23. [PMID: 15960762 PMCID: PMC1571530 DOI: 10.1111/j.1469-7580.2005.00419.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
In amphibia, steroidogenesis remains quiescent in distinct seasonal periods, but the mechanism by which spermatogenesis is maintained under low steroidogenic conditions is not clear. In the present study, testosterone location in the testes of Rana catesbeiana was investigated immunohistochemically during breeding (summer) and nonbreeding (winter) periods. In winter, the scarce interstitial tissue exhibited occasional testosterone immunopositivity in the interstitial cells but the cytoplasm of primordial germ cells (PG cells) was clearly immunopositive. By contrast, in summer, PG cells contained little or no immunoreactivity whereas strong immunolabelling was present in the well-developed interstitial tissue. These results suggest that PG cells could retain testosterone during winter. This androgen reservoir could be involved in the control of early spermatogenesis in winter and/or to guarantee spermiogenesis and spermiation in the next spring/summer. The weak or negative immunoreaction in the summer PG cells might reflect consumption of androgen reservoir by the intense spermatogenic activity from spring to summer. Thus, besides acting as stem cells, PG cells of R. catesbeiana could exert an androgen regulatory role during seasonal spermatogenesis.
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Affiliation(s)
- E Sasso-Cerri
- Department of Morphology, Dental School, São Paulo State University (UNESP), CEP-14801-903 Araraquara (SP), Brazil.
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Lee SK, Veeramachaneni DNR. Subchronic Exposure to Low Concentrations of Di-n-Butyl Phthalate Disrupts Spermatogenesis in Xenopus laevis Frogs. Toxicol Sci 2005; 84:394-407. [PMID: 15659570 DOI: 10.1093/toxsci/kfi087] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Due to its widespread use and production, di-n-butyl phthalate (DBP) has become an environmental contaminant. It has been detected in a variety of environmental strata worldwide, including air, water, and soil. Also, monobutyl phthalate, the major metabolite of DBP, has been detected in a variety of human matrices. As a proven endocrine disruptive compound, DBP may contribute to global amphibian declines at much lower concentrations than tested thus far. We evaluated the effects of low concentrations of DBP on spermatogenesis in Xenopus laevis, the African clawed frog. Xenopus tadpoles were exposed to 0, 0.1, 0.5, 1.0, 5.0, or 10.0 ppm DBP, beginning at sexual differentiation (Nieuwkoop and Faber stage 52; 3 weeks of age) and continuing until 100% of controls metamorphosed (stage 66; 8 weeks of age). Upon necropsy at 33 weeks, 4-6% of DBP-treated frogs had only one testis, and 2-4% had retained oviducts. In all DBP treatment groups, seminiferous tubule diameter and the average number of germ cell nests per tubule were lower, and the number of tubules with no germ cells was significantly higher (p < 0.05). The percent of secondary spermatogonial cell nests significantly decreased (p < 0.05) in 1.0, 5.0, and 10.0 ppm groups. Several lesions occurred in DBP-exposed testes including denudation of germ cells, vacuolization of Sertoli cell cytoplasm, thickening of lamina propria of seminiferous tubules, and focal lymphocytic infiltration. Entire sections of testes containing almost exclusively mature spermatozoa were found in 1.0, 5.0, and 10.0 ppm DBP-exposed testes, indicating impairment of spermiation. Testicular hypoplasia and seminiferous tubular dysgenesis were also evident in DBP-treated frogs. Thus, subchronic exposure to low concentrations of DBP impairs spermatogenesis in Xenopus laevis frogs.
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Affiliation(s)
- Shannon K Lee
- Animal Reproduction and Biotechnology Laboratory, Colorado State University, Fort Collins, Colorado 80523, USA
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