Cultures of Skin Fragments of Salamandra salamandra salamandra (L.) Larvae

As part of a study on the pigmentary system of Salamandra salamandra salamandra (L.), we cultured skin fragments of 7–10-day-old larvae in order to examine the expression of molecules implicated in cellular adhesion and migration and in regulating cell-cell relationships. Keratinocytes, fibroblasts, Leydig cells, xanthophores, and melanophores migrated from the fragments and were observed in the outgrowth. Keratinocytes and fibroblasts organized into an epidermal layer and an underlying “dermal portion.” The chromatophores were always located below the epithelial cells, often with fibroblasts. We examined by immunocytochemistry the expression of fibronectin, β₁-integrin, L-CAM, and A-CAM in the cultures. Many keratinocytes, fibroblasts, and Leydig cells expressed all the signal molecules tested. Xanthophores and melanophores were only immunoreactive to the anti-adhesion molecules antisera. Since the molecules tested are known to play a role in cell adhesion, growth, and spreading, as well as in regulating tissue differentiation and in maintaining normal tissue morphology, we may hypothesize that in Salamandra salamandra salamandra fibronectin, β₁-integrin, L-, and A-CAMS concertedly act to stabilize the architecture of the outgrowth and regulate the relationships between chromatophores and those between chromatophores and the other elements of the skin culture.     

Untersuchungen zur Bildung der Vomerspange beiSalamandra salamandra (L.)

Zusammenfassung BeiSalamandra salamandra wurde die Entwicklung der Vomerspangen anhand von Exstirpations- und Transplantationsversuchen vor und während der Metamorphose untersucht. Die Vomerspange bildet sich aus Bindegewebe, das am Caudalrand des Larvenvomer liegt. Exstirpierte Vomerteile werden nicht regeneriert. Ein kurzer caudaler Abschnitt der larvalen Vomerzahnleiste genügt für die vollständige Ausbildung der Zahnleiste der Vomerspange. Wird die Spitze der auswachsenden Vomerspange reseziert, bleibt die Spange unvollständig. Die Bildung des Definitivvomer bleibt davon unberührt. In die Subcutis der Rumpfhaut transplantiertes Gewebe der sich bildenden Vomerspange bleibt zwar erhalten, wächst aber nicht weiter. In den Spangenbildungsbereich eingefügte Rumpfhaut verhindert das Auswachsen der Vomerspange.

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Investigations on the development of the vomerine bar inSalamandra salamandra (L.)

Summary The development of the vomerine bar inSalamandra salamandra was studied by amputation and transplantation procedures before and during metamorphosis. The bar of the vomer arises from the connective tissue near the caudal margin of the larval vomer. The larval vomer does not regenerate after amputation. A short caudal part of its dental lamina is sufficient for the outgrowing of the complete dental lamina of the vomerine bar. If the tip of the outgrowing vomerine bar is removed, the bar will remain incomplete, which procedure has no influence on the development of the definitive vomer. The material of the developing vomerine bar transplanted to the subepithelial connective tissue of the skin remains intact, but does not continue to grow. Fragments of the skin transplanted to the region from which the bar of the vomer arises prevent the development of the bar.

     

Zur Evolution der Embryonal- bzw. Larvalentwicklung bei Salamandra1

In the genus Salamandra occur mainly two kinds of propagation. The european spotted salamander (Salamandra salamandra) is ovoviviparous and lays a great number of larvas into the water, whereas the alpine salamander (Salamandra atra) gives birth to completely transformed gilless young ones. There are, however, several races of spotted salamander which are also viviparous. The development of such a variety, Salamandra salamandra bernardezi, is described and compared with the generation of the alpine salamander. The emancipation of the development of the larvas from their life in the water has certainly happened in several cases independent of each other under various oecological circumstances. Besides a race of spotted salamander was said to exist in a mountain lake in central Spain at about 6000 ft. This assertion proved to be wrong. The development of the embryo and the larva takes place in exactly the same way as with our native species. The results of the experiments of Mr. Kammerer are dicussed on the basis of the facts at our disposal.     

Ultrastructural and ultracytochemical studies of the gill epithelium in the larvae of Salamandra salamandra (Amphibia,Urodela)

Summary The morphology of Salamandra salamandra (Linné, 1758) larva gills is described by scanning and transmission electron microscopy. Three main cell types comprising the surface of the gill epithelium are described: (a) pavement cell, (b) ciliary cell and (c) mitochondria-rich cell (MRC). Two subtypes of MRC were distinguished by their ultrastructural characteristics: a fibrillar cell and a tubulovesicular cell. K^ü-dependent-nitrophenyl-phosphatase (K-NPPase) activity, indicative of Na^ü-K^ü-ATPase activity was confined to the basolateral membranes of the pavement cells. MRC were devoid of such activity. Possible relationships between structure and function of the different cell types are discussed.     

Breeding Habitat Selection of Salamandra salamandra (Linnaeus, 1758) in the Most Arid Zone of its European Distribution Range: Application to Conservation Management

The influence of environmental variables on the selection of a water body as breeding habitat by Salamandra salamandra was studied in an arid zone located in the southwestern part of its distribution range. From November 2002 to October 2003, 50 water bodies were monitored in the south east of the Iberian Peninsula. Environmental data were submitted to a stepwise logistic regression analysis at macrohabitat, water body typology and microhabitat scales in order to establish the main factors influencing the use of a given water body as breeding habitat by this species. A significant degree of dependence between the reproduction of Salamandra salamandra and environmental variables was observed at all of these levels. These results should be taken into account when populations of this species are subjected to management and/or recovery programmes in arid areas.     

Developmental Changes in the Epidermal Surface Cells of Salamander Larva

Epidermal surface cells were studied ultrastructurally and histochemically at various larval stages in Salamandra salamandra. The most outstanding cellular structures undergoing changes were found to be secretory vesicles, mitochondria and tonofilaments. The highest density of secretory vesicles was noticed immediately after birth, declining in number at later stages and almost disappearing at metamorphosis. The mitochondria, whose appearance at early stages indicates a high metabolic activity, hypertrophy and degenerate close to metamorphosis. Simultaneously, there is an increase in the cellular tonofilaments' density reaching its climax with keratinization.     

Priority effects of the early breeding fire salamander on the late breeding banded newt

Early breeding intraguild predators may have advantages over late breeding predators via priority effects; early breeding predators may reduce shared prey resources before late breeders appear and may also prey upon the late breeders. Here we show that predatory larvae of the late-breeding predatory banded newt, Triturus vittatus vittatus, occupy the same temporary pond toward the end of the developmental period of the early-breeding predatory fire salamander, Salamandra salamandra, resulting in a large size disparity between larvae of these two species while they co-occur. We conducted outdoor artificial pool experiments to assess priority effects of large larval Salamandra at the end of their larval development period, on recently hatched larval Triturus. We also assessed how artificial vegetation may influence larval Triturus performance in the presence or absence of Salamandra Salamandra, introduced into the experimental pools two weeks prior to the newt larvae, strongly reduced invertebrate prey abundance shared by these two predatory urodeles and with only a one week period of overlap, strongly reduced abundance of Triturus larvae. The artificial vegetation had only a small ameliorating effect on Triturus survival when Salamandra was present. Triturus size at metamorphosis (snout-tail length) was significantly larger in the Salamandra pools, presumably due to a combination of a strong “thinning effect” and greater vulnerability of smaller Triturus individuals to predation by Salamandra. Time to metamorphosis was not significantly affected by Salamandra. These results have conservation implications as T. v. vittatus is listed as highly endangered and may also explain the largely negative spatial association of the two species. Handling editor: K. Martens     

Xanthophore migration from the dermis to the epidermis and dermal remodeling during Salamandra salamandra salamandra (L.) larval development

During larval development of Salamandra salamandra salamandra chromatophores organize to form the definitive pigment pattern constituted by a black background with yellow patches that are characterized by epidermal xanthophores and dermal iridophores. Simultaneously the dermis undergoes remodeling from the larval stage to that typical of the adult. In the present study we ultrastucturally and immunocytochemically examined skin fragments of S. s. salamandra larvae and juveniles in order to investigate the modalities of xanthophore migration and differentiation in the context of dermal remodeling from the larval to adult stage. Semithin and thin sections showed that the dermis in newly born larvae consists of a compact connective tissue (basement lamella), to which fibroblasts and xanthophores adhere, and of a loose deep collagen layer. As larval development proceeds, fibroblasts and xanthophores invade the basement lamella, skin glands develop and the adult dermis forms. At metamorphosis, xanthophores reach the epidermis crossing through the basal lamina. We examined immunocytochemically the expression of signal molecules, such as fibronectin, vitronectin, beta1-integrin, chondroitin sulfate, E-cadherin, N-cadherin and plasminogen activator, which are known to be involved in regulating morphogenetic events. Their role in dermal remodeling and in pigment pattern formation is discussed.     

A histochemical study of the microglial cells in the brain of Salamandra salamandra by lectin binding.

Seven biotinylated lectins were utilized as histochemical markers for the study of microglial cells in the brain of Salamandra salamandra. It has been demonstrated that SBA, BSA-I, BSA-I-B4 and RCA120 label the microglial cells and, on the basis of the binding selectivity of the single lectins for specific carbohydrates, it was found that alpha-galactosyl residues are present in high density on the microglial membrane of S. salamandra. The reaction was localized not only to the ramified microglial cells, but also to other round cells without extensions, interpreted as ameboid microglial cells. The results show that lectin binding is a reliable molecular probe for identifying microglial cells in urodels.     

Die Bedeutung desRamus palatinus für die Vomerspangenbildung beiSalamandra salamandra (L.)

Zusammenfassung BeiSalamandra salamandra wurde der Einfluß desRamus palatinus (VII.) und der Lage des Vomer auf die sich während der Metamorphose bildende Vomerspange untersucht. Eine Durchtrennung des Nerven stört das Wachstum der Spange nicht, da der Nerr rasch regeneriert. Nach Durchtrennung und Verlagerung desRamus palatinus bildet sich jedoch keine Vomerspange, ebenso nicht nach Exstirpation eines Teiles des Nerven. Nach Entnahme von Nervenstücken nach Beginn der Metamorphose entwikkeln sich Teilspangen. Das Vorhandensein eines intaktenRamus palatinus ist offenbar Voraussetzung für das Auswachsen der neuen knöchernen Vomerspange. Die Richtung des Spangenwachstums ist nicht von einer bestimmten Lage des Larvenvomer abhängig.

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The significance of theramus palatinus to the development of the vomerine bar inSalamandra salamandra (L.)

Summary The influence of theramus palatinus (VII.) and the postion of the vomer on the vomerine bar, which develops during metamorphosis, was studied by various amputation procedures. Cutting off the nerve cord does not prevent the development of the vomerine bar, as the nerve soon regenerates, whereas cutting off and displacement as well as the removal of portions of theramus palatinus do prevent development. Removal of portions of the nerve cord during metamorphosis produces only parts of the vomerine bar. Obviously an intact ramus palatinus is necessary for the outgrowth of the novel osseous vomerine bar. The course of this outgrowth is independent of the position of the larval vomer.

Für die Unterstützung bei der Anfertigung dieser Arbeit danke ich herzlich Herrn Professor Dr. H. Hartwig, Zoologisches Institut der Universität Köln     

Immunocytochemical localisation of lectins in cells of Phaseolus vulgaris L. seeds

Antibodies against pure E₄- and L₄-lectins from the seeds of Phaseolus vulgaris L. raised in rabbits were made monospecific by immunoaffinity chromatography on E₄- or L₄-lectin Sepharose 4B columns. Localisation of lectins in bean seeds was investigated by indirect immunofluorescence and by electron microscopy on sections stained with colloidal gold particles coated with monospecific anti-E₄- and anti-L₄-IgG. In parenchyma cells from the cotyledons both E- and L-type lectins were found inside the protein bodies. Apparently the matrix of all protein bodies contained both types of lectins. On the other hand in vascular and in axis cells the two types of lectins were localised in the cytoplasm, outside the protein bodies. Thus these findings suggest different roles for the lectins: in cotyledons this may be a specific form of N storage, while in vascular and axis cells lectins may have a more direct metabolic part to play.     

Growth and behaviour of six species of amphibian larvae in a winter pond in Israel

The effect of different ecological niches on growth and behaviour of larvae of four frogs (Bufo viridis, Hyla arborea, Pelobates syriacus, Rana ridibunda), and two salamanders (Salamandra salamandra and Triturus vittatus) found in a winter pond was studied. S. salamandra, T. vittatus, R. ridibunda and B. viridis were found most of the time on the bottom of the pond. However, H. arborea tadpoles were found throughout the pond and were usually sedentary, as compared with P. syriacus which moved up and down constantly. S. salamandra, T. vittatus, R. ridibunda and R viridis tadpoles from the bottom of the pond grew faster than the tadpoles from the surface of the pond. However, tadpoles of H. arborea and P. syriacus growing at the bottom or on the surface developed at similar rates.The invertebrate biomass increases during the summer and was higher at the bottom of the pond than at the surface. However the amount of chlorophyll a was about the same at the surface and at the bottom of the pond. S. salamandra and T. vittatus tadpoles feed on various types of of invertebrates, R. ridibunda and H. arborea and B. viridis tadpoles feed on vascular plants and algae, and P. syriacus tadpoles feed on both invertebrates and plants.     

Indications for a Phagocytic Capacity of Smooth Muscle Cells in the Testicular Wall of Salamandra salamandra (L.) (Amphibia,Urodela)

In smooth muscle cells forming parts of the testicular wall in the European fire salamander, Salamandra salamandra, phagosomes have been found which contain collagen fibres in different stages of decomposition. As a rule, these cells occur in the regressive glandular part of the testis.     

Ultrastructural studies of the epidermal leydig cell in larvae of Salamandra salamandra (caudata,salamandrida)

Epidermal Leydig cells observed in the ventral epidermis of Salamandra salamandra larvae from birth until metamorphosis are characterized by large vesicles and a supporting Langerhans net. They decline in number after birth and disappear entirely after metamorphosis. The cells change in structure and become larger, thus indicating a process of degeneration. The Leydig cells are continuously removed by macrophagelike cells after birth.     

Characterising adhesiveness ofPhytophthora cinnamomi zoospores during encystment

During encystment,Phytophthora cinnamomi zoospores bind firmly to the host surface. We have developed a microassay to study adhesion of the zoospores to solid surfaces, both biological and non-biological. The results show that timing of the acquisition of adhesiveness during encystment correlates closely with the secretion of high molecular weight glycoproteins. The adhesive phase is short lived, occurring between 1 and 4 min after induction of encystment. During this period, cells that come into contact with a variety of surfaces (glass, plastic, and onion epidermis) become firmly attached, while cells that come into contact with one of these substrata after this period are unable to bind. Our results also show that EGTA inhibits cyst adhesion, while addition of calcium promotes cyst adhesion, especially of cysts more than 4 min old. To help identify the cyst surface component involved in adhesion we tested a number of lectins for their ability to block cyst adhesion. Soybean agglutinin andHelix pomatia agglutinin, lectins which bind to the secreted high molecular weight glycoproteins, both inhibit adhesion in the presence and absence of the hapten sugar, indicating that inhibition was non-specific. Wheatgerm agglutinin, a lectin which does not bind to the cyst surface, also blocked adhesion non-specifically.     

Ultrastructure of epidermis of Salamandra salamandra followed throughout ontogenesis

Summary Ventral epidermal ultrastructure of the amphibian urodele Salamandra salamandra is described and followed throughout its life cycle.Tadpoles were divided into five categories on the basis of the organization of their epidermis and the ultrastructure of its cells. In newly hatched tadpoles the epidermis is arranged in two layers and four types of cells were recognized. The number of epidermal layers increases in the metamorphosing tadpole. At this stage the layers become organized in four strata. Metamorphosis involves the disappearance of some cell types and the appearance of others, typical of the adult epidermis.The significance of these ontogenetic changes in epidermal ultrastructure is discussed in respect to aquatic and terrestrial life habits.     

Imitation of contact inhibition by substrate-bound plasma membrane glycoproteins and lectins in serum-free hormone-supplemented cultures of GH3 cells

N-Acetylneuraminic acid-bearing glycoproteins and lectins isolated from the plasma membrane of GH₃ cells are coupled covalently to glass dishes and are used as substrates for cell culture. Under serum-free, hormone-supplemented culture conditions these coupled molecules inhibit the growth rate of GH₃ cells. This inhibition is non-toxic and is concentrationand time-dependent. For an inhibition of 50% 2 × 10⁶ coupled molecules contacting one cell are needed. The data suggest that specific plasma membrane-located glycoproteins and lectins are involved in the ‘density-dependent growth regulation’.     

Biphasic predators provide biomass subsidies in small freshwater habitats: A case study of spring and cave pools

相似文献   

Contribution à l'étude ultrastructurale des cellules interrénales de Salamandra salamandra L. (Amphibien Urodèle)

Summary The interrenal (adrenocortical) cells of the terrestrian spotted Salamander (Salamandra salamandra L.) show the ultrastructural characteristics of steroid producing cells. Their cytoplasm is strikingly rich in mitochondria with mainly tubular cristae, and in liposomes. The endoplasmic reticulum consists essentially of smooth surfaced tubules. The ribosomes are usually free, but can associate themselves with small portions of tubules of the endoplasmic reticulum.Although all the interrenal cells do not show the same aspect, the differences exhibited by their fine structure do not recall the ultrastructural zonation of the mammalian adrenocortex. Some interrenal cells have a highly developed endoplasmic reticulum and are very poor in liposomes, whereas others have their cytoplasm filled with large liposomes, but are poor in mitochondria and endoplasmic reticulum tubules. These two aspects reflect respectively a high level of hormonal synthesis and a reduced one. Most of the interrenal cells show an intermediate cytological aspect reflecting a moderate secretory activity. Some rare cells characterized by small mitochondria with lamellar cristae occur in the interrenal tissue; their significance is not yet understood. Many interrenal cells are degenerescent.

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Zusammenfassung Die Interrenalzellen von Salamandra salamandra L. zeigen die ultrastrukturellen Kriterien der steroidogenen Zellen. Das Zytoplasma ist sehr reich an Mitochondrien, welche vornehmlich tubuläre Cristae haben, und an Liposomen. Das endoplasmatische Retikulum besteht hauptsächlich aus glatten Tubuli. Die Ribosomen sind meistens frei oder können sich an kurze Teile von Tubuli des endoplasmatischen Retikulums binden.Obwohl alle Interrenalzellen nicht das gleiche Aussehen haben, erinnern die Unterschiede ihrer Ultrastruktur nicht an die feinstrukturelle Zonierung der Nebennierenrinde der Säuger. Verschiedene Interrenalzellen sind sehr reich an endoplasmatischem Retikulum, haben aber nur wenige Liposomen, während andere Zellen ihr Zytoplasma aufgefüllt haben mit großen Liposomen, aber nur wenige Mitochondrien und Tubuli des endoplasmatischen Retikulums zeigen. Diese zwei Aspekte deuten auf eine starke, beziehungsweise eine schwache Aktivität der Hormonsynthese. Die meisten Interrenalzellen haben ein intermediäres zytologisches Bild welches eine mittelmäßige Aktivität reflektiert. Man trifft seltener Zellen an, welche kleine Mitochondrien mit lamellaren Cristae haben, und deren Bedeutung noch zu präzisieren bleibt, ferner zahlreiche degenerierende Zellen.

     

Morphologische Studie über den Reissnerschen Faden bei niederen Wirbeltieren

Zusammenfassung Die licht- und elektronenmikroskopische Untersuchung des Reissnerschen Fadens bei Pristella riddlei Meek und Larven von Salamandra salamandra terrestris zeigt im gesamten Verlauf des Reissnerschen Fadens Anlagerungen von Zelldetritus. Durch diese Beobachtung wird Olssons Theorie einer Transportfunktion des Reissnerschen Fadens gestützt.

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Summary In a light and electron microscope study on Reissner's fibre of Pristella riddlei Meek and larvae of Salamandra salamandra terrestris it is shown, that there are appositions of cell detritus in the whole length of Reissner's fibre. This observation supports Olsson's theory of a transport function of Reissner's fibre.

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Großenteils im Institut für Histologie und experimentelle Biologie der Universität München (Direktor: Professor Dr. med. R. Bachmann) und mit Unterstützung durch die Deutsche Forschungsgemeinschaft durchgeführt.