The immature part of the testis in Salamandra salamandra (L.) (amphibia, urodela).

Schindelmeiser, Jochen; Greven, Hartmut; Bergmann, Martin

doi:10.1679/aohc.46.159

Cited by 14 publications

(11 citation statements)

References 23 publications

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“…11 The number of testicular lobes depends on the age of the animal. 3,12 Testis with multiple lobes were described in various species: Desmognathus fuscus, Diemyctylus viridescens, Diemyctylus torosus, and Salamandra atra ; Triturus marmoratus 15 ; Salamandra salamandra 3,16,12,17 , Bolitoglossa occidentalis, B. rostrata, Dendrotriton bromeliacia, Pseudoeurycea goebeli 18 , Pleurodeles waltl. 19 Other species have simple testes, formed by one lobe, regardless of their age, as Eurycea quadridigitata, 20 Salamandrina terdigitata 5 and Lissotriton italicus.…”

Section: Testicular Structurementioning

confidence: 99%

Testicular structure and germ cells morphology in salamanders

Uribe

Mejía-Roa

2014

Spermatogenesis

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Section: Testicular Structurementioning

confidence: 99%

Testicular structure and germ cells morphology in salamanders

Uribe

Mejía-Roa

2014

Spermatogenesis

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“…A number of studies have reported on the fine structure of different aspects of spermatogenesis in several species of urodels, e.g., Pleurodeles wnltlii (Picheral, 1967(Picheral, , 1972a(Picheral, ,b,c, 1979; D. fuscus (Lommen, 1970); Salamandra salamandra (Bergmann et al, 1982;Schindelmeiser et al, 1985); Ambystoma mexicanum (Keyhani and Lemanski, 1981;Miltner and Armstrong, 1983).…”

Section: Urodelesmentioning

confidence: 99%

Spermatogenesis in nonmammalian vertebrates

Pudney

1995

Microscopy Res & Technique

178

120

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Spermatogenesis appears to be a fairly conserved process throughout the vertebrate series. Thus, spermatogonia develop into spermatocytes that undergo meiosis to produce spermatids which enter spermiogenesis where they undergo a morphological transformation into spermatozoa. There is, however, variation amongst the vertebrates in how germ cell development and maturation is accomplished. This difference can be broadly divided into two distinct patterns, one present in anamniotes (fish, amphibia) and the other in amniotes (reptiles, birds, mammals). For anamniotes, spermatogenesis occurs in spermatocysts (cysts) which for most species develop within seminiferous lobules. Cysts are produced when a Sertoli cell becomes associated with a primary spermatogonium. Mitotic divisions of the primary spermatogonium produce a cohort of secondary spermatogonia that are enclosed by the Sertoli cell which forms the wall of the cyst. With spermatogenic progression a clone of isogeneic spermatozoa is produced which are released, by rupture of the cyst, into the lumen of the seminiferous lobule. Following spermiation, the Sertoli cell degenerates. For anamniotes, therefore, there is no permanent germinal epithelium since spermatocysts have to be replaced during successive breeding seasons. By contrast, spermatogenesis in amniotes does not occur in cysts but in seminiferous tubules that possess a permanent population of Sertoli cells and spermatogonia which act as a germ cell reservoir for succeeding bouts of spermatogenic activity. There is, in general, a greater variation in the organization of the testis and pattern of spermatogenesis in the anamniotes compared to amniotes. This is primarily due to the fact there is more reproductive diversity in anamniotes ranging from a relatively unspecialized condition where gametes are simply released into the aqueous environment to highly specialized strategies involving internal fertilization. These differences are obviously reflected in the mode of spermatogenesis and this is particularly true of the stage of spermiogenesis where the morphology of the species-specific spermatozoon is determined. Moreover, unlike amniotes, many anamniotes display a spermatogenic wave manifest, depending upon the species, either at the level of the cyst or seminiferous lobule. This variation in the organization of the testis makes certain anamniotes perfect models for investigating germ cell development and maturation. For instance, the presence of a spermatogenic wave provides an opportunity to manually isolate discrete germ cell stages for analysis of specific Sertoli/germ cell interactions. Furthermore, for many anamniotes, germ cells mature in association with a morphologically poorly developed Sertoli cell. This seeming independence of Sertoli cell regulation allows the in vitro culture of isolated germ cells of some species of anamniotes through several developmental stages. Thus, due either to the anatomical organization of the testis, or structural simplicity of the germinal units, nonmammalian vert...

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“…Thus, PGC is the term used in this study and in others that we conducted previously [Sasso-Cerri et al, 2004. This term was used in a classical morphological study in amphibians [Schindelmeiser et al, 1983] and has been maintained in more recent studies [Paniagua et al, 1990;Arenas et al, 2001;Sáez et al, 2004;Flament et al, 2009]. According to Flament et al [2009], some species of amphibians might be used for the study of factors required to maintain PGCs in adult testes as well as factors triggering their differentiation.…”

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confidence: 99%

“…it occurs in groups/cysts of germ cells derived from a single primordial germ cell (PGC) that are synchronized in the same stage of cellular differentiation [Schindelmeiser et al, 1983]. Each germinal cyst, surrounded by Sertoli cells [Lofts, 1974], is located within a compartment called a seminiferous lobule [Grier, 1992].…”

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confidence: 99%

“…In the testes of adult amphibians, PGC is the term used to define the most primordial spermatogonia that are maintained in the periphery of the seminiferous lobules, as isolated and large germ cells surrounded by Sertoli cells, exhibiting a typical large and polymorphic nucleus with evident nucleoli [Schindelmeiser et al, 1983;Arenas et al, 2001;Sasso-Cerri et al, 2004;Sasso-Cerri et al, 2005;Flament et al, 2009]. In the literature, discrepancies in terminology are present, as these isolated primordial spermatogonia have been named primordial spermatogonia, spermatogonial stem cells [Pierantoni et al, 2002] and primary spermatogonia [Kawasaki et al, 2006;Ferreira et al, 2008;Santos and Oliveira, 2008]; this last name has also been given to more advanced stages of spermatogonia within groups/cysts [Haider and Passia, 1981;Arenas et al 2001].…”

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confidence: 99%

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Primordial Germ Cells (Spermatogonial Stem Cells) of Bullfrogs Express Sex Hormone-Binding Globulin and Steroid Receptors during Seasonal Spermatogenesis

Caneguim

Beltrame

Luz

et al. 2012

Cells Tissues Organs

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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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The immature part of the testis in Salamandra salamandra (L.) (amphibia, urodela).

Cited by 14 publications

References 23 publications

Testicular structure and germ cells morphology in salamanders

Testicular structure and germ cells morphology in salamanders

Spermatogenesis in nonmammalian vertebrates

Primordial Germ Cells (Spermatogonial Stem Cells) of Bullfrogs Express Sex Hormone-Binding Globulin and Steroid Receptors during Seasonal Spermatogenesis

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