bluuebunny/crossref_metadata_2025 huggingface dataset:
Improving the Quality of Miniature Pig Somatic Cell Nuclear Transfer Blastocysts: Aggregation of SCNT Embryos at the Four‐cell Stage
Authors: Terashita Y , Sugimura S , Kudo Y , Amano R , Hiradate Y , Sato E
Published: April 2010

Contents

Miniature pigs share many similar characteristics such as anatomy, physiology and body size with humans and are expected to become important animal models for therapeutic cloning using embryonic stem cells (ESCs) derived by somatic cell nuclear transfer (SCNT). In the present study, we observed that miniature pig SCNT blastocysts possessed a lower total number of nuclei and a lower percentage of POU5F1‐positive cells than those possessed by in vitro fertilized (IVF) blastocysts. To overcome these problems, we evaluated the applicability of aggregating miniature pig SCNT embryos at the four‐cell stage. We showed that (i) aggregation of two or three miniature pig SCNT embryos at the four‐cell stage improves the total number of nuclei and the percentage of POU5F1‐positive cells in blastocysts, and (ii) IVF blastocysts with low cell numbers induced by the removal of two blastomeres at the four‐cell stage did not exhibit a decrease in the percentage of POU5F1‐positive cells. These results suggest that the aggregation of miniature pig SCNT embryos at the four‐cell stage can be a useful technique for improving the quality of miniature pig SCNT blastocysts and indicating that improvement in the percentage of POU5F1‐positive cells in aggregated SCNT embryos is not simply the consequence of increased cell numbers.
Effect of CPS14217C>A genotype on valproic‐acid‐induced hyperammonemia
Authors: Yagi Mariko , Nakamura Tsutomu , Okizuka Yo , Oyazato Yoshinobu , Kawasaki Yoko , Tsuneishi Shuichi , Sakaeda Toshiyuki , Matsuo Masafumi , Okumura Katsuhiko , Okamura Noboru
Published: April 2010

Background:  In order to clarify the factors causing hyperammonemia and to predict occurrences during treatment with valproic acid (VPA), we investigated the effect of the genetic polymorphism of carbamoyl‐phosphate synthase 1 (CPS14217C>A) on susceptibility of hyperammonemia, together with the effect of coadministration of other anticonvulsants.

Methods:  Seventy‐nine patients with epilepsy were enrolled, and five of them had hyperammonemia. Univariate and multivariate logistic regression analyses were performed.

Results:  The aspartate aminotransferase level in the patients with hyperammonemia was significantly higher than that in those without hyperammonemia. The risk of hyperammonemia was significantly influenced by the number of anticonvulsants concomitantly administered with VPA. Also, the distribution of the CPS14217C>A genotype differed depending on whether the patients had hyperammonemia or not. No significant effects of CPS14217 genotypes and the number of anticonvulsants coadministered with VPA on the serum concentrations of VPA were observed. The multivariate logistic regression analysis showed that the concomitant administration of two or more anticonvulsants with VPA and the heterozygous or homozygous carrier state of the A allele of the CPS14217C>A polymorphism were independent risk factors for developing hyperammonemia.

Conclusions:  These findings suggested that in epileptic patients undergoing VPA therapy, CPS14217A polymorphism and the number of coadministered anticonvulsants would be considered as risk factors for hyperammonemia, even if the serum VPA concentrations were controlled.
A METHOD FOR SILVER STAINING NERVE FIBRES IN VERY THICK SECTIONS AND IN SUITABLE WHOLE PREPARATIONS
Authors: PALMGREN AXEL
Published: April 2010

Abstract. In a previous article (1948) the author introduced a rapid method for silver staining nerve fibres in ordinary, mounted paraffin sections (5–25 microns in thickness). By the modification of this method described below, being adjusted to very thick sections (100–300 microns), much more extensive connections of nerve fibres and their ramifications can be demonstrated. The modification can also be used for staining suitable, not sectioned preparations in toto. Some results are shown in photomicrographs.
The Enzyme Droplets of Vertebrate Kidney
Authors: Pugh D.
Published: April 2010

The properties and distribution of enzyme droplets of kidney, liver, and gut of several vertebrates were investigated.

Qualitative and quantitative differences in enzyme content existed in droplets from different sources. There was usually a closer correlation between the properties of the inclusions and their tissue origin than between the droplets of different organs obtained from one animal. The most noticeable specific characteristic was the relatively low acid phosphatase content of the lizard tissues. In all animals the enzyme droplets of liver and gut were considerably smaller than those of the proximal region of the nephron. The collecting ducts of bird and lizard kidneys possessed droplets of a different composition from those of the proximal segment, these bodies were considered to be associated with external secretion rather than with renal function.
Endotheliochorial Placentation in a Pangolin, Manis tetradactyla
Authors: Heath Everett , Amachree Mara
Published: April 2010

The placenta of a pangolin, Manis tetradactyla, was examined grossly and histologically. The placenta was arranged in longitudinal bands of 2–3 mm width. Microscopically there was a deep labyrinth and an underlying layer of distended endometrial glands. A narrow junctional zone was present containing syncytiotrophoblast. Thoughout the labyrinth cytotrophoblast and syncytiotrophoblast were observed in contact with maternal capillaries. The placentation was considered to be endotheliochorial in type.
Norepinephrine Response in Brown Adipose Tissue from Newborn Rats
Authors: Vallin Ingert
Published: April 2010

Morphological changes in brown adipose tissue of newborn rats induced by norepinephrine injection include a swelling of the mitochondria and a decreased fat content. The mitochondrial swelling is gradually more pronounced with time and reaches its maximum 30 minutes after injection of the hormone. A regression towards an unswollen state is then observed, but morphological changes are still found 60 minutes after the injection. Lipolysis continues over the period of time measured. Hormonally evoked respiratory stimulation and the mitochondrial swelling in the tissue seem to reach their maximum simultaneously.
Ultrastructural Analysis of the Neuroendocrine Apparatus of Oncopeltus fasciatus (Heteroptera)
Authors: Unnithan G. C. , Bern Howard A. , Nayar K. K.
Published: April 2010

In Oncopeltus fasciatus, the A‐cells of the pars intercerebralis and their tracts are stainable in situ with the performic acid‐victoria blue (PAVB) method. The axons from these cells, after traversing the corpus cardiacum, terminate in the anterior part of the aorta which thus serves as the neurohemal organ.

Ultrastructurally, four types of secretory neurons are distinguishable in the pars intercerebralis region: pic‐I with granules measuring 1000–3000 Å in diameter; pic‐II with granules of irregular size and shape, the elongate ones showing mean dimensions of 2400 × 1400 Å; pic‐III with less electron‐dense granules measuring 1000–2700 Å in diameter; pic‐IV, present not only in the pars intercerebralis but also in adjacent regions of the brain, with variable proportions of granules measuring 700–1800 A and dense‐cored vesicles measuring 1000–2400 Å.

The nervi corporis cardiaci contain at least three types of neurosecretory axons, based on granule content, presumably representing pic‐I, pic‐II and pic‐III neurons.

The wall of the aorta contains endings of at least three distinct types, again representing pic‐I, pic‐II and pic‐III neurons, and thus provides the neurohemal site for these three types of protocerebral neurosecretory cells. Axons of pic‐IV neurons appear to enter the cerebral neuropil.

The corpus cardiacum is composed of two types of parenchymal secretory cells, with electron‐dense granules measuring 1300–3000 Å and 1000–2300 Å in diameter, respectively. The corpus cardiacum also contains interstitial cells and some axons of extrinsic origin, with and without granules.

The corpus allatum may be paired or median, and receives a small number of at least two types of axons. The corpora allata of some reproducing females show a large number of PAVB‐stainable inclusions which appear to be modified cytoplasmic organelles, but are definitely not neurosecretory material.

The hypocerebral ganglion is composed of two types of secretory‐appearing neurons and glial cells. The two neuronal types contain secretory granules, 1000–3000 Å and 900–2100 Å in diameter, respectively. Axons of the recurrent nerve also may contain occasional granules.

In this heteropteran insect, the two principal functions of the corpus cardiacum appear to be spatially separated: the neurohemal function is subserved by the aortic wall, which permits release of material into both the aortic lumen and the hemocoel, and the intrinsic endocrine function is possessed by the parenchymal cells.
The Structure of the Mouthparts of Some Galypterate Dipteran Larvae in Relation to Their Feeding Habits
Authors: Roberts Michael J.
Published: April 2010

The anatomy of the head and the structure of the mouthparts is described for calypterate larvae of differing feeding habits.

The way in which the skeletal parts of the cephalopharynx and the musculature are adapted to the type of food is discussed and particular reference is made to the action of the mouthparts in the carnivorous larva ofLimnophora ripariaFallen.
Fine Structure and Histochemistry of the Choroid Plexus of the Teleost Leuciscus rutilus
Authors: Obermüller‐Wilén Helena
Published: April 2010

Analyses of the fine structure of the posterior choroid plexus in the teleost Leuciscus rutilus and the determination of the presence and function of the enzymes acid and alkaline phosphatases, ATPase and glucose‐6‐phosphatase confirm similarities between these epithelial cells and the saccus dorsalis and also with the epithelial cells of the choroid plexus found in mammals. The teleost plexus cells contain coated vesicles which are derived from the plasmalemma as well as from the Golgi complex. Moreover, they contain multivesicular bodies and Iysosomes. These organelles function in the absorption of substances from the cerebrospinal fluid and in the breakdown of these substances within the cells. The investigated enzymes play an important role in the secretion of electrolytes into the cerebrospinal fluid by active membrane transport.
Occurrence of Urotensin II (Bladder‐Contracting Activity) in the Caudal Spinal Cord of Anamniote Vertebrates
Authors: Bern Howard A. , Gunther Robert , Johnson Donald W. , Nishioka Richard S.
Published: April 2010

Urotensin II (bladder‐contracting activity) is present in the caudal spinal cords of teleosts, elasmobranchs, holosteans, and chondrosteans, in order of decreasing activity. It is questionably present in holocephalans and probably absent from lungfishes.

Cyclostomes and tailed amphibians show no evidence for any specific caudal urotensin II.

The pharmacological evidence parallels the cytological evidence for the occurrence of a caudal neurosecretory system.
On the Structure of the Avian Maculae
Authors: Jørgensen J. Mørup , Andersen T.
Published: April 2010

The maculae of the labyrinths of several avian species were examined. The striola of the macula utriculi and lagenae is tri‐zonal, consisting of two zones of hair cells type I (HC I) located on each side of a middle zone of hair cells type II (HC II). An exception is the mute swan, in which the macula utriculi has a striola consisting of one broad zone of HC I. The macula sacculi is, in its central part, mainly consisting of HC I, and the striola does not have a tri‐zonal structure.

The hair cells in the macula utriculi are polarized with their kinociliar end oriented towards the striola, while in the macula sacculi and lagenae they are oriented away from this dividing line.

A varying number, from 1 to 12, of HC I are enclosed within the same nerve chalice. The macula sacculi seems to contain chalices with slightly more HC I than the two other maculae do.
Succinic Dehydrogenase Distribution in the Pectoralis Muscle of Several East African Birds
Authors: Stickland N. C.
Published: April 2010

The distribution of succinic dehydrogenase activity was investigated in the pectoralis muscle of thirteen East African birds, representing five Orders. It was found that the pectoralis muscle of the most primitive birds studied (Galliformes) contained all “white” muscle fibres whereas the more advanced birds (Passeriformes) had all “red” muscle fibres. Intermediate Orders had mostly a mixture of red and white muscle fibres. There also appeared to be a direct relationship between body size and average muscle fibre size. However, it was concluded that the most important factor in relation to the muscle structure is the bird's mode of flight. The relationship with the degree of evolution and body size only held true in so far as the birds which had developed the facility for sustained flight, by increasing their red muscle fibre content, were also smaller in size and constituted the more “evolved” Orders of birds. In support of this it was noted that migratory birds (i.e. engaging in sustained flight) from more primitive Orders also had a high red muscle fibre content in their pectoralis muscles.
The Corpus Cardiacum Neurosecretory Cells of Schistocerca gregaria. Electron Microscopy of Resting and Secreting Cells
Authors: Krogh Inger Marie , Nermann Tom Christian
Published: April 2010

The corpora cardiaca of Schistocerca consist of a neurohaemal part containing mainly extrinsic neurosecretory axons coming from the brain, and of a glandular part consisting mainly of intrinsic neurosecretory cells. Some extrinsic axons penetrate into the glandular region, and innervate intrinsic corpus cardiacum neurosecretory cells. The fine structure of the latter has been examined and related to other neurosecretory cell types. Secretion occurs by exocytosis. Omega‐profiles are more frequently observed in corpora cardiaca stimulated electrically or by acetylcholine than in the controls.
Observations on Eye Movements in Amphibian Larvae
Authors: de Saint‐Aubain M. L.
Published: April 2010

Observations have shown that amphibian larvae, contrary to what has been stated in the literature, have different kinds of eye movements. All of the anurans observed (Xenopus, Rana, Bufo, Hyperoleus and Bombina) have some kind of reflex eye movements effected through stimuli from the labyrinth organs as a response to movements of the body, while only Rana and Bufo have spontaneous scanning movements. Of the urodelians (Ambystoma and Triturus), larvae of Ambystoma have no observable eye movements, while Triturus larvae have reflex eye movements associated with movements of the neck, as well as spontaneous scanning movements; both kinds of movements differ from those seen in Anura.
Aminergic and Indoleamine Accumulating Neurons in the Retina of the River Lamprey (Lampetra fluviatilis)
Authors: Ehinger Berndt , Holmberg Kaj , Öhman Peter
Published: April 2010

Tissues were processed for fluorescence microscopy of biogenic amines according to the method of Falck and Hillarp. Normal animals, and animals injected with α‐methylnoradrenaline or 5,6‐dihydroxytryptamine were used. Catecholamine containing neurons (junctional cells) occur in the innermost rows of cell bodies of the inner nuclear layer (INL) and close to the vitreous surface. Catecholamine containing fibers occur in three layers: (1) an outer layer around the innermost perikarya of the INL, which is a condition not found in retinas of gnathostome chordates; (2) a middle layer within the outer third of the inner synaptic layer (ISL), separated from the outer layer by ganglion cell axons; (3) a sparse inner layer within the innermost third of the ISL. A few catecholamine containing fibers were seen to extend from the innermost region of the INL to the outer synaptic layer. The position of the junctional cells in the lamprey corresponds to that in gnathostome chordates, but whereas all catecholamine containing fiber layers in gnathostomes are located sclerally to the optic fiber layer and within the ISL, the middle and the inner fiber layers in the lamprey occur vitreally to the optic fiber layer. Indoleamine accumulating neurons occur in the innermost row of perikarya of the INL and close to the vitreous surface. Those of the INL send fine, varicose branches to the ISL forming a network which is somewhat denser at the inner and outer borders of the ISL than in its middle. The indoleamine accumulating terminals do not ramify within the INL in contrast to the catecholamine containing terminals.
Hematology of the Norwegian Lemming (Lemmus lemmus(L.))
Authors: Wiger Richard
Published: April 2010

Basic hematological parameters of laboratory‐reared Lemmus lemmus have been investigated. The results have been summarized together with those from ten other species of microtine rodents. Climatic conditions, especially the microclimate of the subnivean air space, have been considered to offer possible explanations for the higher values in L. trimucronatus compared to L. Lemmus.
Ultrastructure of Oenocytoids from Two Spiders, Pisaura mirabilis and Trochosa terricola (Araneae)
Authors: Midttun Bjørn , Jensen Helge
Published: April 2010

Haemocytes of two spiders, Pisaura mirabilis Clerk and Trochosa terricola Thor, have been investigated. The oenocytoids are a conspicuous feature of the intracardiac haemocyte population in these spiders. Mature cells contain large amounts of crystalloid material. The crystalloid inclusions consist of piles or bundles made up of numerous undulating lamellae which have a crystal‐like, hexagonal lattice. When viewed side‐on, the lamellae appear as strings or fibrils with alternating light and dark bands. Mature oenocytoids rupture and release the crystalloid material into the heart lumen. The cells contain a cartwheel nucleus and abundant ribosomes. Mitochondria are few and small. Immature oenocytoids contain little crystalloid material, and resemble insect plasmatocytoids.
Morphology and Histology of the Heart of the Australian Lungfish, Neoceratodus forsteri (Krefft)
Authors: Klitgaard Torben
Published: April 2010

The wall of the sinus venosus consists of densely packed collagen fibres and scattered striated muscle fibres. Striated muscle makes up the spongiosa of the auricle but is completely absent from the auricular wall, which only contains connective tissue. The lateral lobes of the auricle are small and do not reach the ventral side of the heart. The hard nucleus in the auriculo‐ventricular plug consists mainly of dense elastic tissue, not of cartilage as in the other lungfishes. The general morphology of the heart, including the entrance of the pulmonary vein, the auriculo‐ventricular plug and the spiral valve of the bulbus cordis, is similar to that of the other lungfishes, so arterial and venous blood can probably be separated in the same way in Neoceratodus up to the level of the bulbus cordis. However, Neoceratodus lacks the horizontal septum in the distal part of the bulbus and all branchial arteries are emitted from an undivided space in the short truncus arteriosus. Thus the mechanism of separation in the distal bulbus of Neoceratodus must be very different from that of the other lungfishes.
The “Intracranial Joint”Versus the “Ventral Otic Fissure”
Authors: Bjerring Hans C.
Published: April 2010

The issue of the origin and phylogenetic significance of the “intracranial joint” and the “ventral otic fissure” has in recent years been much debated. Two antipodal opinions exist. One calls for their origin independently of one another and maintains that they represent relatively primitive features. The other holds them to be specializations derived from an erstwhile basicranial fissure which either became extended up to the roof of the cranium or, from a position close behind the hypophyseal fossa, migrated backwards, as the posterior myodome developed. In this paper, the former view is upheld, whereas the latter is demolished.
Developmental Changes and Lytic Activity in Aminergic Neurons of Microstomum lineare (Turbellaria)
Authors: Reuter Maria
Published: April 2010

The ultrastructure of and the presence of lytic activity in aminergic neurons from zooids representing different developmental stages were compared. The observations indicate clear differences between neurons of developing and mature zooids, and show that lytic activity occurs in the neurons of this turbellarian species. The differences in ultrastructure, size and nucleoplasms (NP) index motivate a division of the aminergic neurons of the zooids into three categories: (1) small aminergic neurons (SN) which occur in developing zooids; (2) flocculent aminergic neurons (FN) characterized by a network of flocculent splittings in the cytoplasm; (3) vacuolated aminergic neurons (VN) with large membrane limited vacuoles occupying a large part of the perikaryon. Slight acid phosphatase (AcPase) activity occurs in GERL of SN. An increased amount of AcPase reaction products in the Golgi apparatus, primary lysosomes and autophagosomes are observed in FN. Typical for VN are prominent lead deposits in the large vacuoles. The development and functional significance of the large vacuole are discussed.
Smelling Behaviour of Urodele Amphibians in an Aquatic Environment: Study in Pleurodeles waltl.
Authors: Joly Pierre , Cuillère Louis
Published: April 2010

In urodele amphibians, the olfactory input is important in the triggering and controlling of sexual and feeding behaviours. In an aquatic environment, a water sample is drawn through the nostrils to the olfactory organs. This sampling consists of the following acts: the buccal floor is pressed down by the action of the tongue muscles and skeleton, the consequence of which is the transmission of a depression to the olfactory chambers via the choanas; water is then aspirated and flows over the sensory areas of the olfactory mucosa before entering the buccal cavity via the choanas; water is finally expelled in front of the animal, the opening of the jaws being synchronous to a fast upward movement of the buccal floor. A thermistor telemetry technique enabled us to show a relationship between smelling behaviour and feeding behaviour, particularly variations in intensity and frequency of smelling behaviour related to the chemical qualities of the surroundings.
On the Polarization and Innervation of the Pars Inferior Sensory Epithelia of the Herring Labyrinth
Authors: Jensen Jan Chr.
Published: April 2010

The macula sacculi and the macula lagenae of the herring, Clupea harengus L., were examined by light microscopy, the macula lagenae is large compared to what is normal among non‐ostariophysan fishes, the morphological polarization of the hair cells in the inferior maculae shows a pattern which is similar to that usually seen in teleost fishes. The fibres in the nerves supplying the macula sacculi and the macula lagenae were counted and their diameters measured. The ramulus saccularis is divided in two separate ramuli innervating populations of hair cells with different morphological polarization. The saccular rostral nerve trunk contains 1800–2300 fibres, with 1300–1800 fibres in the caudal nerve trunk. The lagenar nerve is composed of 2100–4000 fibres. The fibre diameters are 1–14 μm in all ramuli. Silver staining of the nerve axoplasm reveals a unique differentiation of the maculae, which can be divided into a central area surrounded by a peripheral part. The hair cells in the central area are innervated by thick nerve fibres (5–14 μm diameter) as well as a few thin nerve fibres (about 1 μm diameter), while the receptor cells in the peripheral area are exclusively innervated by thin fibres having diameters of 2 μm or less.
Anatomical and Behavioral Differences Among Threespine Sticklebacks: the Marine Form, the Landlocked Form and Their Hybrids
Authors: Honma Yoshiharu , Tamura Eimitsu
Published: April 2010

In order to elucidate the mechanisms and degree of isolation in the landlocked form of the threespine stickleback, Gasterosteus aculeatus (L.), inhabiting the Shinano and Agano Rivers that flow into the Japan Sea, comparative studies on the morphology, behavior and histology were made of the marine form, the landlocked form and their hybrids reared in the laboratory. The body shape, coloration and behavior of reciprocal hybrids were almost intermediate between the two parent forms. From January to February, the testis of the hybrid between the female marine form and the male landlocked form is occupied exclusively by spermatocytes and some spermatids. However, a small number of large cells, identified as macrophages, are found invading the seminiferous tubules, indicating the occurrence of phagocytosis. On the other hand, ripe functional eggs appear in the ovary in May, i.e. the breeding season. The eggs deposited into the nest do not develop even when the hybrids display the same mating behavior as their parents. Functional sperms are found in the testis of the hybrid between female landlocked and male marine forms at the period of breeding. However, only a single female lived until March. In the ovary of this female, all eggs reaching vitellogenesis (= primary yolk globule stage) are collapsed, while the younger oocytes appear in healthy condition. The hybrid female of this pairing seemed also to be sterile.
Histochemical Observations on Carbohydrates in Connective Tissue Structures and Basement Membranes of Hemi‐ and Cephalochordates
Authors: Welsch U. , Schumacher U.
Published: April 2010

Connective tissue components and light microscopical basement membranes of Saccoglossus horsti (Enteropneusta, Hemichordata) and Branchiostoma lanceolatum have been studied with Aldehyde Fuchsin, the PAS‐reaction, Alcian Blue (pH 0.2) and fluorescein conjugated (FITC) lectins: concanavalin A (Con A), wheat germ agglutinin (WGA), soy bean agglutinin (SBA), leucoagglutinin (LA), Griffonia (Bandeiraea) simplicifolia agglutinin (GSA I), Griffonia (Bandeiraea) simplicifolia isolectin B4 (GS I B4). In Saccoglossus and Branchiostoma, both the PAS‐reaction and Alcian blue give a good general survey over the distribution of the principal basement membranes and connective tissue structures. Lectin binding proved less intensive in Saccoglossus than in Branchiostoma, in which FITC‐Con A, FITC‐GSA and FITC‐WGA react strongly with the dermal (especially in the metapleural folds) and axial connective tissue, as well as the myosepta, the gill arch skeleton and numerous basement membranes. Con A outlines distinctly the major blood vessels in the pharyngeal area. Con A, WGA, GSA and GSI B4 are markers for basement membranes.
Ultrastructural Observations on the Spermatozoon, Oocyte and Fertilization Process in Gonapodasmius, a Gonochoristic Trematode (Trematoda: Digenea: Didymozoidae)
Authors: Justine Jean‐Lou , Mattei Xavier
Published: April 2010

Observations were performed in the uterus of a female Gonapodasmius sp., a gonochoristic didymozoid Trematode. The oocyte is a round cell 6 μm in diameter, which shows a ‘nucleolus‐like cytoplasmic body’ and cortical granules. The spermatozoon is filiform, mobile and about 50 μm long. There is no acrosome. The anterior tip of the spermatozoon contains two centrioles made up of singlets and cortical microtubules with associated glycocalyx. The centrioles are continued as two axonemes of the classical 9 + ‘1’ pattern of flatworms, accompanied by a mitochondrion and a short row of cortical longitudinal microtubules. It is the posterior part of the sperm cell which contains the nucleus. At the outset of fertilization, the anterior part of the spermatozoon coils around the oocyte and penetrates it by lateral fusion. The posterior region of the spermatozoon, with the nucleus, is the last part to enter the oocyte, after passing through a perforation in the forming eggshell. The whole spermatozoon thus penetrates the female cell.
Effects of Castration and Androgen‐treatment on Pituitary and Testes of the Three‐spined Stickleback, Gasterosteus aculeatus L., in the Breeding Season
Authors: Bor Bertil , Reschke Maria , Peute Jan , van den Hurk Robert
Published: April 2010

Methyltestosterone (MT) (35 μg/l aquarium water) suppresses steroid production in the testes of sham‐operated fish, as studied enzyme histochemically. This treatment also diminishes the volume of the proximal pars distalis, as well as the area of the gonadotropic (GTH) cell nuclei. Such effects were not found in MT‐treated castrated fish. Castration alone led to a partial degranulation of the GTH‐cells as compared with sham‐operated controls. Extensively dilated granulated endoplasmic reticulum was found in the GTH‐cells of some of the castrated animals and also in GTH‐cells of some castrated fish that had been treated with MT. The possibility of a non‐steroidal feedback mechanism from testes to pituitary is discussed. No effects of the treatments were observed on prolactin cells and on the second basophilic cell type (GTH II?, TSH?).
An Ultrastructural Account of Otoplanid Turbellaria Neuroanatomy I. The cerebral ganglion and the peripheral nerve net
Authors: Ferrero Enrico Antonio , Lanfranchi Alberto , Bedini Celina
Published: April 2010

The otoplanid nervous system investigated in Otoplana truncaspina Lanfranchi, 1969 and Parotoplanella heterorhabditica Lanfranchi, 1969 consits of: (a) an ellipsoidal cerebral ganglion located between the gut and the cephalic intestine and invested by a fibrillar collagen‐like capsule 0.3 μm thick; (b) anterior extracapsular ganglion cell clusters; (c) a peripheral nerve plexus locally thickened at the level of the epithelial sensory and glandular areas, with extensive synaptic connections. At least two neuron types can be identified within the ganglion: (a) an inner layer close to the central neuropile of the 1st type of neurons, showing a vesicular cytoplasm rich in RER and Golgi complexes processing both round, clear, 25–45 nm in diameter, and dense cored vesicles, 50–80 nm in diameter; (b) an outer layer of the 2nd type of neurons, adjoining the capsule and filled with uniformly dense vesicles, 60–90 nm in diameter. Synaptic endings in the neuropile are provided with clear vesicles and dense cored vesicles or uniformly dense vesicles. The presynaptic side has paramembranous projections channelling the vesicles to the active zone; omega‐like profiles are also observed. Thin banded muscle fibres run within the brain. A comparison is drawn with the other turbellarian neuron types described in the literature, to suggest their possible function. The functional implications of the synaptic ultrastructure are discussed.
First Evidence of an Altitudinal Variation in the Brain Size of Triturus alpestris alpestris (Laur.) (Amphibia, Caudata, Salamandridae)
Authors: Breuil M. , Thireau Michel
Published: April 2010

This study deals with geographical variations in brain‐body weight relationships in the alpine newt, Triturus alpestris alpestris. According to the canonical axis, C.A., the mean allometry in this species is 0.473±0.03; an allometry value of 0.5 is considered to be characteristic of Caudata. No significant difference was observed between the four reduced major axes (R.M.A.) of lowland animal samples (mean value of the pooled samples, C.A. = 0.469±0.210). In contrast, between the mountain samples a significant difference exists, the R.M.A. in the sample from l'Alpe d'Huez (Isère, France) being 0.331±0.57 as compared to 0.72±0.18 in the sample from Durmitor (Montenegro, Yugoslavia). In spite of this difference, their encephalisation index (Ie) did not differ significantly, having on average a value of 118.18±8.5, against Īe = 93.8±8.0 for lowland samples. A significant difference in encephalisation index between mountain and lowland alpine newts thus exists. This is probably the first observation in vertebrates of an encephalisation index increase with altitude. A biological hypothesis is proposed to explain this peculiar observation.
The Dentition and Feeding Mechanism in Adults of the Southern Hemisphere Lamprey Geotria australis Gray
Authors: Hilliard R. W. , Potter I. C. , Macey D. J.
Published: April 2010

Scanning electron micrographs of the teeth and sections and dissections of the head have been used to describe the functional interrelationships between the dentition and associated cartilages, muscles and ligaments in adults of the southern hemisphere lamprey Geotria australis. These studies, together with manipulation of the piston and oral disc in living specimens, elucidated the probable feeding mechanism in this species. The main cutting action appears to result from a scissoring movement brought about by the rapid interlocking of the three sharp and stout cusps of the transverse lingual lamina with large grooves on the rear face of the supraoral lamina. The movement of excised flesh back through the oral passage to the pharynx would be facilitated by the action of the pair of strongly cuspid longitudinal lingual laminae. The unique oral disc teeth of G. australis are apparently adapted to allow the disc to slide forward over the host and yet restrict any tendency to slip backwards.
Effect of Cytochalasin B on Eggs of Atlantic Salmon and Rainbow Trout
Authors: Bolla Sylvie , Refstie Terje
Published: April 2010

Cytochalasin B action has been investigated in polyploidisation and gynogenesis in Atlantic salmon and rainbow trout. Solutions of 10, 20, 30 and 50 mg/1 were used to treat eggs from 35 h° to the 2‐, 4‐ and 8‐cell stages for rainbow trout, from 35 h° to the 2‐ and 4‐cell stages, and 50 h° to the 8‐cell stage for salmon. Survival rate was low in all treated groups. Low frequencies of polyploid and gynogenetic individuals were observed in embryos and alevins by means of two methods: DNA analysis by flow cytometry and chromosome counting. All polyploids observed were triploids without evidence of mosaicism. A few spontaneous diploid gynogenetic rainbow trout were registrated, as well as spontaneous triploid salmon, in controls.
Distribution of Nerve Elements Showing FMRFamide‐like Immunoreactivity in Hydromedusae
Authors: Mackie G. O. , Singla C. L. , Stell W. K.
Published: April 2010

Immunofluorescence tests with antisera to various peptides reveal the presence of a FMRFamide‐like peptide in neurons of hydromedusae belonging to three orders. An avian pancreatic polypeptide‐like peptide may also be present in certain neurons. Distribution of FMRFamide‐like immunoreactivity (Fa‐IR) has been studied in Proboscidactyla (O. Limnomedusae), Phialidium and Aequorea (O. Leptomedusae) and Aglantha (O. Trachymedusae). These findings are compared with results obtained with Polyorchis (O. Anthomedusae) by Grimmelikhuijzen and Spencer [J. comp. Neurol. 230, 361 (1984)]. All species show Fa‐IR neurons in the tentacles linked by interconnecting neurites running in the outer marginal nerve ring. A Fa‐IR plexus is present in the manubrium and, except in Aglantha, this system merges with a plexus associated with the subumbrellar radial muscles. As in Polyorchis, the swimming motor neurons are unstained. In contrast to this species, only a small percentage of the neurites composing the nerve rings are stained. The giant axons of Aglantha show no Fa‐IR. The cnidothylaces of Proboscidactyla contain neurons reacting with antisera to FMRFamide and APP. Present evidence suggests that in hydromedusae Fa‐IR is confined to distinct subsets of neurons. These appear to be either sensory units or units supplying smooth muscles, but they are not involved in the innervation of striated muscles.
Aspects on the Ultrastructure of the Cephalic Region in Two Species of Acrobelinae (Nematoda, Cephalobidae)
Authors: Boström Sven
Published: April 2010

The lip structures termed labial probolae, characteristic for the subfamily Acrobelinae, and the anterior sense organs have been studied by electron microscopy. The labial probolae consist of an amorphous tissue with denser strengthenings. They do not contain any sensory structures or musculature. The anterior sense organs consists of: (1) six inner labial sensilla, each with one receptor ending in a pore on a papilla; (2) six outer labial sensilla, each with one receptor ending in the cuticle; (3) four cephalic sensilla, each with two receptors, one ending in a pore on a papilla and the other in the cuticle; (4) two amphids, each with 12 sensory neurons basally; (5) accessory sensilla ventro‐laterally. The combination of several chemoreceptive anterior sensilla and the morphological diversity of the labial probolae within the subfamily may aid in the utilization of different soil microhabitats.
The Question of a Dermohyal in Brachiopterygian Fishes
Authors: Bjerring Hans C.
Published: April 2010

Since the turn of this century it has been suggested between whiles that brachiopterygians (i.e. the species of Polypterus and Calamoichthys) are actinopterygians. One of the arguments used recently by advocates of this widespread contention is the dermohyal, an exoskeletal branchial‐arch element which they assert occurs in both groups. However, this argument has to be rejected: the dermohyal does not exist in brachiopterygian fishes. The writer proposes to maintain the view that brachiopterygians are not actinopterygians until better arguments to the contrary are forthcoming.
Functional Morphology of the Olfactory Organs in the Spiny Dogfish (Squalus acanthias L.) and the Small‐spotted Catshark (Scyliorhinus canicula (L.))
Authors: Theisen Birgit , Zeiske Eckart , Breucker Haide
Published: April 2010

The morphology of the olfactory organs in two sharks, the spiny dogfish and the small‐spotted catshark, was studied by light microscopy and electron microscopy (TEM and SEM). The olfactory epithelium is arranged on olfactory lamellae which are provided with secondary folds. The epithelium mainly consists of microvillous receptor cells, multiciliated supporting cells and basal cells. The find of only one type of receptor cells, the microvillous type, is discussed and the condition considered a derived (apomorphic) character. The route of the water current through the olfactory organ and the different driving forces of the ventilation process are subject to discussion. In both the pelagic dogfish and the bottom‐dwelling catshark the pressure difference between the incurrent and excurrent nostrils achieved by active swimming appears to be the driving force, whereas the role of the beating of the non‐sensory cilia is not evident. In the bottom‐dwelling catshark the ventilation of the olfactory organ is also supported by the respiratory activity.
Ultrastructural Observations on Fertilization in Dionchus remorae (Platyhelminthes, Monogenea, Dionchidae)
Authors: Justine Jean‐Lou , Matter Xavier
Published: April 2010

Ultrastructural observations are presented for some of the stages occurring during fertilization in Dionchus remorae (a gill parasite of Echeneis naucrates) and are believed to be the first published concerning a monogenean. Fertilized female germ cells were found in the ovary. Several loops of the spermatozoon were present within the oocyte cytoplasm; the sperm nucleus became electron lucent and the parallel peripheral doublets of the axonemes became increasingly divergent. The cortical granules in the oocyte were not released immediately after penetration by the spermatozoon. The homogeneity apparently found in the oocyte ultrastructure and process of fertilization in the monogeneans and digeneans contrasts with the variety that exists in their sperm ultrastructure.
The Fine Structure of the Integument of Free‐Living and Parasitic Copepods. A Review
Authors: Bresciani J.
Published: April 2010

A perusal of the literature on copepod cuticles has been made, and results of the investigation of six species made by the author are included in this review.

The integument of copepods is of the arthropod type. Pore canals and other structures traversing the cuticle, common in most arthropods, are not always present in free‐living and some parasitic copepods.

In parasitic forms, with advanced morphological changes, the cuticle is generally very thin and the epicuticle in many species forms external microvilli‐like structures. In the copepods hitherto investigated the epicuticle is probably the sole layer present in the cuticle.

Some copepods show specialized regions of the cuticular surface, the function of which still remains obscure. Integumental organs and integumental structures are numerous and variable. The association of bacteria with the cuticle has been observed in many species.

The structure of the integument of parasitic species lacking an alimentary tube and in close contact with the host tissue or hemocoelic cavity supports the idea that the integument could be the obligatory site of nutrient uptake. In spite of the relatively few species of copepods that have been investigated, a remarkable variation of cuticular fine structure has been revealed.
Fine Structure of Heart, Pericardium and Glomerular Vessel in Cephalodiscus gracilis M'Intosh, 1882 (Pterobranchia, Hemichordata)
Authors: Dilly Peter Noel , Welsch Ulrich , Rehkämper Gerd
Published: April 2010

Heart, pericardium and glomerular vessel of Cephalodiscus gracilis have been studied with the electron microscope. The lumen of the heart is lined by a basal lamina and an associated epithelium, composed of myoepithelial cells with well developed thin and thick myofilaments. The heart is located in the pericardial cavity, which is deliminated by the pericardium. The latter is composed of two flat layers of myoepithelia with fused basal laminae. The outer layer of the pericardium is the protocoelomic lining, and the inner layer is the ‘parietal’ pericardial epithelium. The myoepithelium forming the heart wall can be considered to represent the ‘visceral’ pericardial epithelium. The spacious glomerular vessel is lined by a basal lamina, on which typical podocytes rest. These cells indicate that ultrafiltration takes place through the wall of the glomerular vessel. The lumen of the vessel contains fine granular material (presumably precipitated blood proteins), fibrils with a faint cross striation, suggesting that they represent collagen, and stellate cells, which in part line the vessel. Since ultrafiltration requires hydrostatic pressure, it is inferred that the blood flow is from the dorsal region then through the heart and into the glomerular vessel.
Fine Structure of Tentacles, Arms and Associated Coelomic Structures of Cephalodiscus gracilis (Pterobranchia, Hemichordata)
Authors: Dilly Peter Noel , Welsch Ulrich , Rehkämper Gerd
Published: April 2010

The tentacles of the pterobranch Cephalodiscus, a hemisessile ciliary feeder, originate from the lateral aspects of the arms and are covered by an innervated epithelium, the majority of its cells bearing microvilli. Each side of a tentacle has two rows of ciliated cells and additional glandular cells. The coelomic spaces in the tentacles are lined by cross‐striated myoepithelial cells, allowing rapid movements of the tentacles. One, possibly two, blood vessels accompany the coelomic canal. On their outer sides the arms are covered by a simple ciliated epithelium with intra‐epithelial nerve fibres; the inner side is covered by vacuolar cells. On both sides different types of exocrine cells occur. The collar canals of the mesocoel are of complicated structure. Ventrally their epithelium is pseudostratified and ciliated; dorsally it is lower and forms a fold with specialized cross‐striated myoepithelial cells of the coelomic lining.

Arms, tentacles, associated coelomic spaces and the collar canal of the mesocoel are considered to be functionally interrelated. It is assumed that rapid regulation of the pore width is possible and even necessary when the tentacular apparatus is retracted, which presumably leads to an increase of hydrostatic pressure in the coelom.
Hormonal Control of Seasonal Growth in a Temperate Zone Toad Bufo bufo
Authors: Wind‐Larsen Hanne , Jørgensen C. Barker
Published: April 2010

Young toads were exposed to a light regimen of 12L/12D at 21°C and fed meal‐worms before hibernation in the autumn, when the toads reduce feeding and discontinue growth, and after hibernation in the spring, when feeding and growth is resumed. In the autumn treatment of the toads with bovine growth hormone maintained feeding and growth; in the spring the treatment protracted the period of feeding and growth. Thyroxin had no obvious effects on growth. It is concluded that the annual growth pattern of temperate zone toads is controlled by an internal rhythm in the secretion of growth hormone.
The Cardiogastric Gland and Alimentary Tract of Caenolestid Marsupials
Authors: Richardson K. C. , Bowden T. A. J. , Myers P.
Published: April 2010

The stomach of the South American marsupial family Caenolestidae has a gland on its lesser curvature around the cardia. This cardiogastric gland is bi‐lobed, typically 11times5 mm and bears a distinctive, highly folded mucosa which forms sac‐like invaginations. These open into the stomach lumen via 40–60 slit‐like orifices. The gland mucosa contains unbranched gastric glands which are considerably longer than those of other gastric glands present elsewhere in the stomach. The cells within the cardiogastric gland show intense eosinophilic staining properties, with the parietal cells being larger than those found in other regions of the stomach, as well as being arranged in clusters. Argentaffin cells are not present in the stomach mucosa. The gross morphology of the stomach and intestine is similar to that found in small carnivorous marsupials.
Immunohistochemical Identification of the Adenohypophysial Cells in the Indian Paddy Field Frog, Rana limnocharis
Authors: Kar Satyabrata , Naik Dhruba Raj
Published: April 2010

Cells of the pituitary pars distalis (PD) and pars intermedia (PI) in the frog Rana limnocharis have been identified by an unlabelled antibody enzyme method using antisera developed in rabbit against mammalian hypophysial hormones. On the basis of their immunoreactivity, six types of cells, viz. thyrotropic (TSH), gonadotropic (GTH), prolactin (PRL), growth hormone (GH), corticotropic (ACTH) and melanotropic (MSH), cells have been recognized. GTH and PRL cells are distributed throughout the PD. GH cells usually occur in the anterodorsal and central region of the gland. Immunoreactive TSH cells are fewer in number and are localized in the ventromedian region of the PD. Cells showing immunoreactivity to ACTH 1–24 antiserum are encountered in the rostroventral part of the PD. Cells of the PI also show immunoreactivity to ACTH 1–24 antiserum. PI cells cross‐react with α‐MSH antiserum at all dilutions up to 1: 50 000. However, when the same antiserum was used at dilutions up to 1: 20 000, the ACTH cells of the PD also showed cross‐reactivity.
Immunocytochemical Demonstration of Serotonin and Neuropeptides in the Nervous System of Gyrodactylus salaris (Monogenea)
Authors: Reuter Maria
Published: April 2010

A whole mount immunocytochemical (ICC) method has been used for the investigation of immunoreactivity (IR) to the molluscan cardioactive peptide FMRF‐amide, to 9 vertebrate neuropeptides—leu‐enkephalin, growth hormone‐releasing factor (GRF), urotensin I, urotensin II, bovine pancreatic peptide (BPP), β‐endorphin, substance P, secretin and insulin—and to the bioamine 5‐HT in the nervous system (NS) of the trematode Gyrodactylus salaris belonging to the taxon Monogenea. Positive results were obtained using antisera to FMRF‐amide, leu‐enkephalin, urotensin I, GRF and to 5‐HT. The present results are the first documentation of the presence of neuroregulatory peptides and a bioamine in the nervous system (NS) of Monogenea. Differences in the distribution pattern of the IR to the different antisera indicate that different subsets of neurons are revealed. In addition, details of the basic neuroanatomical pattern in monogeneans are confirmed by the whole mount ICC method used in this study. Negative results were obtained with antisera to urotensin II, substance P, β‐endorphin, secretin, insulin and bovine pancreatic polypeptide (BPP).