Human follicle-stimulating hormone modulation of adrenal gland activity in the Italian crested newt, Triturus carnifex (Amphibia, Urodela)

The aim of the present study was to verify if human FSH influences the adrenal gland of the newt, Triturus carnifex. Newts were given intraperitoneal injections of human FSH throughout the periods of February-March, and December-January; periods in which newt FSH levels are normally very low. The effects of human FSH on adrenal gland activity were observed in the morphological features of the steroidogenic and chromaffin adrenal cells, and in the serum levels of aldosterone, corticosterone, norepinephrine and epinephrine. The effect of human FSH on the steroidogenic cells was significant during the February-March period; the quantity of cytoplasmic lipids decreased, and the corticosteroid serum levels increased. During the December-January period, the human FSH effects were negligible. The effect of human FSH on the chromaffin cells was significant during both the February-March, and the December-January periods. During February-March, the human FSH increased the numeric ratio of norepinephrine granules to epinephrine granules, and increased the epinephrine serum levels. During December-January, the human FSH decreased the numeric ratio of norepinephrine granules to epinephrine granules, and increased the norepinephrine serum levels. The results of the present study show that human follicle-stimulating hormone influences the activity of the newt adrenal gland, thus indicating a relationship between the annual sexual cycle and the annual adrenal cycle of the newt.     

The retention of learning during metamorphosis of the crested newt (Triturus cristatus)

Larvae of the urodeles, Triturus cristatus, can be taught a simple discrimination task for food reward. The preference established by training is retained by the adult newts after metamorphosis. No significant change in the natural preference of these animals occurs after metamorphosis. Adult animals appear to be more difficult to train than the larvae.     

Endocrine-disrupting effects of nonylphenol in the newt, Triturus carnifex (Amphibia, Urodela)

The aim of our study was to verify whether environmental concentrations of nonylphenol influenced the adrenal gland of Triturus carnifex. Newts were exposed to 19 μg/L nominal concentration of nonylphenol throughout the periods of December-January and March-April, corresponding to different stages of the chromaffin cell functional cycle. The morphological features of the steroidogenic and chromaffin tissues, and the serum levels of ACTH, aldosterone, corticosterone, norepinephrine and epinephrine were evaluated. Nonylphenol did not influence ACTH serum levels. During the two periods examined, the steroidogenic tissue had the same reaction: the quantity of cytoplasmic lipids, and the corticosteroid serum levels, decreased, suggesting the inhibition of synthesis and release of corticosteroids. During the two periods examined, the chromaffin tissue reacted differently to nonylphenol. During December-January, the numeric ratio of norepinephrine granules to epinephrine granules, and the epinephrine serum levels, increased, suggesting the stimulation of epinephrine release. During March-April, the numeric ratio of norepinephrine granules to epinephrine granules did not change, and the norepinephrine serum levels decreased, suggesting the inhibition of norepinephrine release. Our results show that nonylphenol influences the activity of the newt adrenal gland; considering the physiological role of this gland, our results suggest that nonylphenol may contribute to amphibian decline.     

The population dynamics of the crested newt Triturus cristatus at a pond in southern England

The population dynamics of a population of crested newts Triturus cristatus were studied in 1983 at a pond in southern England, Three length classes of individuals were distinguished. Adult newts between 67 and 84 mm snout-vent length migrated to the pond in spring, on days when the temperature approached 5°C. Males tended to arrive earlier than females and to remain in the pond for longer. A second period of immigration of smaller adults, between 57 and 70 mm in length, took place in the autumn; these newts overwintered in the water and may have been about to breed for the first time. Juvenile newts measuring between 40 and 51 mm in length also visited the pond during the spring and summer. Immigrant male and juvenile crested newts were significantly higher in weight than emigrants: there was no significant difference between the weights of immigrating and emigrating females.     

The evolution of the adult body form of the crested newt (Triturus cristatus superspecies,Caudata, Salamandridae)

We characterized the adult body form of the crested newt (Triturus cristatus superspecies) and explored its evolution. From seven morphometric traits, we determined that body size, interlimb distance and head width define the body form. None of the morphometric traits showed a phylogenetic signal. Three body‐shape morphotypes (Triturus dobrogicus + T. cristatus, Triturus carnifex + Triturus macedonicus and Triturus karelinii + Triturus arntzeni) and three body‐size morphotypes (T. dobrogicus, T. cristatus and all other crested newts) could be recognized. The ancestral phenotype (a large body with a short trunk and a wide head) characterized T. karelinii and T. arntzeni. Triturus carnifex and T. macedonicus had a somewhat different phenotype (large body and wide head, accompanied by mild body elongation). The most derived phenotype included body size reduction and more pronounced body elongation in T. cristatus and, especially, in T. dobrogicus. Body elongation occurred by trunk lengthening but not head and tail lengthening. Additionally, contrary to other tetrapods, evolutionary axis elongation in crested newts was followed by a decrease in body size. We advocate the hypothesis that ecology drives the evolution of body form in crested newts.     

The organization of serotonin-immunoreactive neuronal systems in the brain of the crested newt,Triturus cristatus carnifex Laur.

Summary The distribution of serotonin (5-HT) immunoreactive structures has been investigated in the brain of the crested newt by means of indirect immunofluorescence, and unlabeled antibody peroxidase-antiperoxidase-complex (PAP) or biotin-avidin-system (BAS) techniques. In the newt, the bulk of the serotoninergic system extends from the raphe region of the medulla oblongata, through the isthmus, toward the mesencephalic tegmentum, and is characterized by pyriform neurons mainly located in a subependymal position, close to the midline. Also in the caudal hypothalamus, in addition to some 5-HT-positive adenohypophysial cells, many immunoreactive CSF-contacting neurons are found lining the paraventricular organ and the nucleus infundibularis dorsalis. A rich serotoninergic innervation was observed in the preoptic area and in the habenular complex. Concerning the telencephalon, immunopositive nerve fibers are encountered in the dorsal pallium, primordium hippocampi, striatum and olfactory bulbs. The general organization of serotoninergic systems in the newt brain exhibit close similarities to that described in higher vertebrates.     

The aerial and aquatic visual acuity of the optomotor response in the crested newt (Triturus cristatus)

Summary Behavioural and electrophysiological experiments using equidistant vertical stripe patterns were performed. The coherence between the visual acuity of the optomotor response and of the recordings from the accessory optic tract could be shown. The possibility of the existence as well of a background movement system as a tectal nearness system with a greater myopia in the newt is discussed.Supported by the Deutsche Forschungsgemeinschaft (Me 365/4 and Sch 132/4)     

The Sexual Behaviour of the Great Crested Newt,Triturus cristatus (Amphibia: Salamandridae)

The sexual behaviour of Triturus cristatus is described. The first stage of sexual behaviour consists of an orientation phase in which the male approaches the female, sniffs her and moves in front of and perpendicular to her. The second stage is a prolonged period of static display with two different tail movements, called Fan and Lash, in 13.8 ± 1.3 bouts (x? ± SE) with intervals of 10.5 ± 0.3 s between bouts. Each bout contains 6.7 ± 0.3 regular Fan beats at a frequency of 0.5–0.8 Hz. This Fanning provides olfactory and mechanical stimulation to the female. 15% of bouts also contain a violent Lash, in which the male rapidly slaps the female's flank. Some Lashes are used to stop the female when she tries to move away. In the third stage of the sexual sequence, the male turns away, Creeps for 6.7 ± 0.3 s (x? ± SE) and then Quivers his tail. A receptive female follows and touches his tail, and the male deposits a spermatophore and then turns to one side with his tail folded along his flank in a position called Brake. The female now approaches again and the male steps away sideways in a movement called Rebrake. After several Rebrakes the male stops, the female touches his tail and the spermatophore may now be picked up in her cloaca. This sequence can be repeated several times during one encounter. This behaviour is discussed in relation to previous studies of courtship in this genus.     

The primary structures of the major and minor hemoglobin-components of adult Andean goose (Chloephaga melanoptera, Anatidae): the mutation Leu----Ser in position 55 of the beta-chains

The primary structures of the hemoglobin components Hb A and Hb D of the adult Andean Goose (Chloephaga melanoptera) are presented. The globin chains were separated on CM-Cellulose in 8M urea buffer. The amino-acid sequences were established by automatic Edman degradation of the globin chains and of the tryptic peptides in liquid- and gas-phase sequenators. The sequences are aligned with those of Greylag Goose (Anser anser) as a biological reference and other sequences of birds. A detailed evaluation of all residues of Andean Goose hemoglobins on the basis of the 12000 known avian globin sequences leads to a molecular pattern for high-altitude respiration of geese. The replacement of functional and structural importance is the unique occurrence of the residue beta 55 Leu----Ser (all other exchanges are functionally neutral), interrupting the same alpha 1 beta 1-interface contact (alpha 119-beta 55) that accounts for high-altitude respiration of the Barheaded Goose (Anser indicus); there the mutation is found on alpha A 119. Loosening the constraints of this interface must be interpreted as a destabilization of the low-affinity T-structure in favour of the high-affinity R-structure. The structural and functional significance of this interface for the molecular biology of high-altitude respiration of the Andean Goose and Barheaded Goose is discussed. Since Hb A consists of alpha A2 beta 2 and Hb D consists of alpha D2 beta 2 the mutation occurring in blood of the Andean Goose affects both hemoglobins whereas in the case of the Barheaded Goose only Hb A is affected. These results show that Hb D can be considered a biological reserve to enlarge situatively the normal hemoglobin function. A general molecular pattern for permanent (selective advantage of high intrinsic oxygen affinity) and transitory (selective advantage of graded oxygen affinities) adaptation to hypoxia is discussed. A survey on the sequence homology of the globin chains of geese (Anserinae) and ducks (Anatinae) is given.     

SEM observations on polar body elimination and changes of the oocyte surface during egg maturation in the newt Triturus alpestris (Amphibia,Urodela)

Summary We have studied the surface of the animal half of ovulated newt eggs recovered from different portions of the oviduct. The germinative area, about 40 m diameter, is localized in the region of the whitish polar spot, about 450 m diameter. The structural changes in the germinative area are connected with the formation and extrusion of the first and second polar bodies. Of the two types of oviductal eggs observed, those covered with microvilli (type 1) were found only in the ostial portions of the oviduct, whilst those covered with microfolds (type 11) were found more distally. The structural difference between these two types may be related to the known reduction in surface area of the cell membrane during oocyte maturation. Offprint requests to: W. Kilarski     

The sexual behaviour of the red-spotted newt, Notophthalmus viridescens (Amphibia: Urodela: Salamandridae)

The sexual behaviour of the red-spotted newt, Notophthalmus viridescens is described. The male can adopt one of two types of behaviour depending on the initial responsiveness of the female. If she is responsive, the male performs a brief lateral (or hula) display, at the end of which one or more spermatophores may be deposited. If she is unresponsive, the male captures the female and a lengthy period of amplexus ensues, followed by spermatophore transfer behaviour. Spermatophore transfer is most successful after amplexus, and a preliminary cost-benefit analysis of the two types of courtship is given. The behaviour is discussed in the context of other urodele amphibians, and in the wider context of male reproductive strategies.     

The distribution of GABA-like-immunoreactive neurons in the brain of the newt,Triturus cristatus carnifex,and the green frog,Rana esculenta

Summary The distribution of -aminobutyric acid (GABA) immunoreactivity was studied in the brain of two amphibian species (Triturus cristatus carnifex, Urodela; Rana esculenta, Anura) by employing a specific GABA antiserum. A noteworthy immunoreactive neuronal system was found in the telencephalic dorsal and medial pallium (primordium pallii dorsalis and primordium hippocampi) and in the olfactory bulbs. In the diencephalic habenular nuclei there was a rich GABAergic innervation, and immunoreactive neurons were observed in the dorsal thalamus. In the hypothalamus the GABA immunoreactivity was found in the preoptic area, the paraventricular organ and in the hypothalamo-hypophysial complex. In the preoptic area of the frog some GABA-immunoreactive CSF-contacting cells were shown. In the optic tectum immunolabeled neurons were present in all the cellular layers. A rich GABAergic innervation characterized both the fibrous layers of the tectum and the neuropil of the tegmentum and interpeduncular nucleus. In the cerebellum, in addition to the Purkinje cells showing a variable immunopositivity, some immunoreactive cell bodies appeared in the central grey. Abundant immunolabeled nerve fibers in the acoustico-lateral area and some immunopositive neurons in the region of the raphe nucleus were observed. In conclusion, the GABAergic central systems, well-developed in the amphibian species studied, were generally characterized by close similarities to the pattern described in mammals.Dedicated to Professor Valdo Mazzi (Dipartimento di Biologia Animale, Università di Torino), in honor of his 70th birthday     

High-altitude respiration of falconiformes. The primary structures and functional properties of the major and minor hemoglobin components of the adult White-Headed Vulture (Trigonoceps occipitalis, Aegypiinae)

The primary structures of the hemoglobin components Hb A and Hb D of White-Headed Vulture (Trigonoceps occipitalis) are presented. The globin chains were separated on CM-Cellulose in 8M urea buffer, the components by FPLC in phosphate buffers. The amino-acid sequences were established by automatic Edman degradation of the globin chains and of the tryptic peptides in liquid phase and gas-phase sequenators. The sequences differ from those of European Black Vulture by only one mutation in the alpha A-chains (alpha 137). The alpha D-chains and the beta-chains are identical. This means that for the first time identical minor components in birds have been found. An updated list of identical globin chains is presented. Hb D exhibited a higher oxygen affinity than Hb A. At pH 7.5 and 38 degrees C P50 values of 0.80 and 0.64 kPa (6.0 and 4.8 mm Hg), respectively. Both hemoglobins showed similar Bohr factors displayed a pronounced sensitivity to inositol hexakis(phosphate), which increased P50 values of Hbs A and D to 4.0 and 3.6 kPa (30 and 26 mm Hg), respectively. The molecular and physiological significance of the findings is discussed with special reference to oxygen transport by hemoglobin at high altitude.     

The Cloaca and Spermatheca of the Female Smooth Newt, Triturus vulgaris L. (Amphibia: Urodela: Salamandridae)

The anatomy and histology of the cloaca and spermatheca of 13 female smooth newts ( Triturus vulgaris ) were studied by light microscopy. The cloaca consists of a short, anterior tube (which receives the oviducts), which opens into a larger, more posterior chamber. The spermatheca, which is the only gland in the cloaca, consists of a mass of exocrine, acinar tubules which empty individually and dorsolaterally into the posterior part of the cloacal tube and all but the most posterior part of the cloacal chamber. Stored sperm are most abundant in the spermathecal tubules during the peak of the breeding season (in May and June); during their period of storage, the sperm do not appear to make intimate contact with the epithelial cells lining the spermathecal tubules. Longterm storage of viable sperm from one breeding season to the next is probably absent in the smooth newt. Sperm storage by and multiple insemination of females both occur in this species and are necessary preconditions for competition between the sperm of different males for the fertilization of eggs. However, sperm competition has not been demonstrated in the smooth newt.     

High-altitude respiration of birds. The primary structures of the major and minor hemoglobin component of adult goshawk (Accipiter gentilis, Accipitrinae)

The primary structures of the hemoglobin components Hb A and Hb D of the adult Goshawk (Accipiter gentilis) are presented. The globin chains were separated on CM-Cellulose in 8M urea buffer. Component separation was achieved by FPLC-chromatography on a TSK SP-5PW column in phosphate-buffers with a linear gradient of NaCl. The amino-acid sequences were established by automated Edman degradation of the globin chains and of the tryptic peptides in liquid-phase and gas-phase sequenators. The sequences are aligned with those of European Black Vulture (Aegypius monachus). Phylogenetic aspects and physiological properties for Goshawk hemoglobin are inferred from sequence data. A detailed evaluation of the oxygen-binding properties has been carried out during a prolonged study of the noteworthy ability of Falconiformes to cope with extremely low oxygen partial pressures, and will be the subject of a forthcoming paper.