bluuebunny/crossref_metadata_2025_split huggingface dataset:
Odontogenesis and amelogenesis in interacting lizard—Quail tissue combinations
Authors: Lemus D. , Coloma L. , Fuenzalida M. , Illanes J. , De La Vega Y. Paz , Ondarza A. , Blanquez M. J. 
Published: February 2005

AbstractIn this study we examined the possible inductive role of the dental papilla from polyphyodont lizard tooth germs. Flank skin sheets of quail ectoderm enzymatically separated from dermal tissue were recombined with lizard tooth papillae and placed on semisolid medium and cultured for 2 days. Subsequently, the recombinants were removed and placed on the chorioallantoic membrane of chick hosts and incubated for 6 days. After this period of 8 days in explant, control tissues differentiated according to their own phenotypes. Lizard dental papilla alone differentiated as fibroblasts. Quail flank skin ectoderm differentiated into epithelial sheets. Intact lizard tooth buds developed into teeth with dentine and incipient enamel. In the best experimental recombinants, advanced and relatively well‐constructed teeth were observed, with clear indications of hard tissue deposition in association with quail epithelium. The results show that mesenchyme of the adult lizard dental papilla and embryonic quail ectoderm of heterotopic origin are capable of carrying out the complex sequence of morphogenetic interactions involved in normal odontogenesis.
Comparative studies on the eye morphology of lungless salamanders, family Plethodontidae, and the effect of miniaturization
Authors: Linke Rüdiger , Roth Gerhard , Rottluff Bernd 
Published: February 2005

AbstractIn seven species of lungless salamanders, family Plethodontidae, ranging from medium to very small in body size and from small to very large in cell size, the morphology of the eye and the retina were investigated. Haller's rule was only partially corroborated. While the smallest species had the relatively largest eyes, the largest two species, having the largest cells, showed the third and fourth largest eyes of the series. An effect of cell size was also found with regard to eye morphology. Small species with small cells as well as large species with large cells had relatively small retinae and relatively large lenses. In contrast, small eyes with relatively large cells had absolutely and relatively large retinae and relatively small lenses.The retinae of all investigated plethodontids showed a morphology typical for land vertebrates with two fiber and three nuclear layers. Rods, cones and double cones could clearly be distinguished. A fovea or area centralis was not found. Retina ganglion cell and photoreceptor counts show that the number of these elements was lower than in salamandrids. However, determination of the resolution power of miniaturized eyes based on morphological and behavioral data shows that this does not seem to constitute a functional disadvantage. The morphological and functional properties and constraints of eyes of miniaturized salamanders are discussed.
Comparative morphology and evolution of cheek pouches in rodents
Authors: Ryan James M. 
Published: February 2005

AbstractThere are two types of cheek pouches in extant rodents. Internal cheek pouches are evaginations of the oral cavity deep to M. platysma and M. sphincter colli profundus, and have evolved independently in some species of the superfamilies Sciuroidea and Muroidea. External, furlined cheek pouches open lateral to and separate from the oral cavity, (also deep to M. platysma and M. sphincter colli profundus), and occur in all species of the families Geomyidae and Heteromyidae. The presence of external, furlined cheek pouches is a synapomorphy for the superfamily Geomyoidea.The posterior retractor muscle of the pouch is derived from facial musculature in sciurids, from trapezius musculature in cricetids, and from both facial and trapezius muscle groups in the Geomyoidea. Differences also exist in the musculature associated with the pouch opening. In the Sciuridae and Cricetidae, the M. buccinatorius muscle group acts as a sphincter to control the size of the pouch opening. In the Geomyoidea, the size of the opening is controlled by the M. orbicularis sacculi in concert with a slip of the M. Platysma myoides.Thin sections and scanning electron micrographs of the pouch tissue reveal the presence of dermal papillae in Phodopus sungorus but not in a close relative, Mesocricetus auratus. All members of the subfamily Cricetinae have a peninsula of highly folded tissue projecting anteriorly from the posteromedial pouch wall. This folding allows for expansion of the pouch walls when food is stored in the pouch.
Ultrastructural evidence of extruding exocytosis of residual bodies in the freshwater sponge Ephydatia fluviatilis
Authors: Willenz Philippe , van de Vyver Gysèle 
Published: February 2005

AbstractExocytosis of residual bodies by choanocytes, archeocytes and endopinacocytes lining the aquiferous system of Ephydatia fluviatilis has been demonstrated using calibrated latex beads and Escherichia coli as tracers. In passing into the mesohyl or the lumen of the exhalant aquiferous canals, beads, and altered bacteria were enveloped by the plasma membrane of the cell containing them. The membrane constricted at a neck region to form extruding vacuoles. This process appeared first in choanocytes and later in other cell types. The occurrence of these buds increased with the length of incubation time, as did the number of particles they contained. Acid phosphatase activity was frequently associated with the particles budding from the cell membrane, confirming that this process followed digestive activity.Membranous vacuoles were recovered from the external medium and observed by TEM and those adhering to the substratum were seen by SEM. These observations proved that vacuoles were released from the sponges. This membrane‐consuming mechanism of exoctyosis implies intense membrane replacement in the digestive cells of the sponge.
Comparative aspects of cerebellar cytoarchitecture in the European eel life cycle
Authors: Bernocchi G. , Biggiogera M. , Barni S. 
Published: February 2005

AbstractThe major anatomical divisions of the cerebellum of the European eel, i.e., corpus cerebelli, lobus vestibulolateralis, and valvula, were studied morphologically and morphometrically. There were differences in cerebellar cytoarchitecture and gross morphology in two stages of the eel life cycle, the trophic stage (yellow eel), and the reproductive stage (silver eel), which are characterized by different degrees of swimming activity. The principal differences between silver and yellow eels in the cytoarchitecture of the corpus cerebelli and the lobus vestibulolateralis were in distribution of Purkinje or Purkinje‐like cells in the molecular layer, which is wider in silver eels, in part because of a decreased thickness of the granular cell layer. In the silver eel, the scattering of Purkinje cells was more evident in the lobus vestibulolateralis where the molecular layer is also thicker. The data indicate the transition from the yellow eel to the silver eel is characterized by a migration of granule cells from the ganglionic cell layer to the internal granular layer and by a further development of molecular layer components, e.g., parallel fibers, Purkinje‐cell dendrites, etc. In contrast, the thickness of the granular layer and of the Purkinje cell layer, limited to the lower part of the valvula, decreased. There is also a slight increase of cerebellar volume in the silver eel. The volume of the lobus vestibulolateralis was constant. Hypertrophy of the valvula and eminentiae granulares is observed and is due to the migration of cells from the granular layer of the corpus cerebelli whose volume slightly decreases. Perhaps the lobus vestibulolateralis also contributes to the increased volume of eminentiae granulares. Our findings suggest that the cerebellum continues to develop during the passage from the trophic to the reproductive stage of the eel. The appearance of new afferents from the lateral line which becomes more visible in the silver eel probably completes cerebellar ontogeny.
Lymph heart musculature in birds
Authors: Budras K.‐ D. , Hullinger R. L. , Rautenfeld D. Berens V. 
Published: February 2005

AbstractDevelopment and innervation of the lymph heart musculature of chicken, emu, rhea, and duck was studied by electron microscopy at posthatch ages from 3 days to adulthood. Development of innervation was monitored by acetylcholinesterase staining. Horseradish peroxidase was used to determine the extent of the transverse tubule network. Chickens were unusual among these birds in that lymph heart myocytes had already undergone a definitive differentiation and degeneration by 3 days. In ducks and ratite birds, lymph heart myocytes more slowly but progressively differentiate a cytomorphology that does not conform in all characteristics to cardiac or skeletal muscle and even resembles in some aspects, smooth muscle. Myofibrils become the dominant cytoplasmic structure, transverse tubules form ‘internal couplings’ with agranular reticulum cisternae, and ‘external couplings’ are formed between myocytes at myomyal junctions. The myomyal junctions also contain AChE‐positive reaction product and some subplasmalemmal vesicles that lack a dense core. The lymph heart myocardium of ducks of 2 weeks demonstrated mitotic figures. In adult ducks the myosatellite cell numbers diminish and a characteristic pattern of myocyte degeneration appears. In juvenile ducks and ratites some myocytes differentiate to conductile cells, much as the conductile myocytes and myofibers of the blood heart. The lymph heart innervation is described, and the role of nerve in differentiation and maintenance of myocyte morphology in the lymph heart is discussed.
Neuromast topography in anuran amphibians
Authors: Lannoo Michael J. 
Published: February 2005

AbstractGeneralized anuran tadpoles across families exhibit a similar neuromast morphology on their heads, as follows: (1) all neuromast lines known for anurans are present; (2) within these lines total neuromast number ranges from about 250 to 320; (3) neuromasts form linear stitches composed of two to three, but sometimes up to five, neuromasts; (4) neuromast linear dimensions are ⩽ 10 μm; and (5) neuromasts contain ⩽ 15 hair cells. Compared with generalized forms, stream, arboreal, carnivorous, and desert‐pond forms have fewer neuromasts but they contain more hair cells. They do not, however, form stitches. Obligate midwater suspension‐feeding forms, including Xenopus (Pipidae), Rhinophrynus (Rhinophyrnidae), and Phrynomerus (Microhylidae), form stitches that contain > six, but potentially up to 18 or more, loosely aggregated neuromasts. Xenopus and Rhinophrynus have large neuromasts (up to 40 μm across). Chiasmocleis (Microhylidae) tadpoles form stiches that are linearly arranged with up to ten neuromasts. Whereas urodeles can have more than one neuromast row per line and may form both linear and transverse stitches, anurans have only one row of neuromasts per line and form only transverse stitches. Neuromasts in anurans tend to be smaller and more circular than in urodeles and positioned flush with the epidermal surface. A greater percentage of anurans form stitches, and anurans have greater intrafamilial variation in stitch formation than do urodeles.
Regenerative response of amputated forelimbs of Xenopus laevis froglets to partial denervation
Authors: Liversage Richard A. , Anderson Meri‐Jo , Korneluk Robert G. 
Published: February 2005

AbstractXenopus laevis froglet forelimbs normally respond to amputational injury by forming a heteromorphic cartilaginous rod‐shaped outgrowth. However, partial denervation of a forelimb by ablation of the N. radialis or the N. ulnaris, followed in 2 days by amputation through the mid radius‐ulna, results in a size deficiency of the regenerative outgrowth 14 and 21 days postamputation. The decreasing quantity of forelimb innervation, as a result of partial denervation by 55 or 45%, apparently has a graded effect on the cell population and on the extent of cartilage development in the outgrowth. As a consequence of amputational injury, a nerve independent response of the periosteum was also found. This response produced considerable thickening in the periosteum and was due to cell proliferation in both the control and denervated cases.
A morphological study of the nervous system of the praesoma of Paulisentis fractus (Acanthocephala: Neoechinorhynchidae)
Authors: Gee Randall J. 
Published: February 2005

AbstractThe nerve pathways in the praesoma are described for a member of the class Eoacanthocephala for the first time. Eleven nerves, five paired and one single, are traced from the cerebral ganglion to their associations with the musculature of the body wall, neck sense organs, and the musculature of the proboscis wall and the invertor muscles of the proboscis. The structure and location of the stutzzelle and series of nerve endings in the hypodermis of the body wall and at the apex of the proboscis are described.
Structure and function of the spermatheca in a snail host of schistosomiasis, Biomphalaria glabrata
Authors: Rogers Steffen H. , Reeder Richard L. 
Published: February 2005

AbstractThe histochemistry and ultrastructure (SEM and TEM) of the spermatheca of Biomphalaria glabrata was investigated to elucidate the function of this organ and to compare its structure and function to similar organs found in other species. The spermatheca has a debris‐filled lumen surrounded by a thin wall of tissue. The cells adjacent to the lumen are of three columnar epithelial cell types. Two cell types have abundant microvilli and mammalian cell‐like organelle distribution and morphology. The above cell types differ in the electron density of their cytoplasms, nuclear morphologies, and organelle content. The third cell type differs from the other two in its cytoplasmic makeup. However, the most distinctive difference is the presence of large numbers of cilia at the apical surface with no evidence of microvilli. These columnar cells rest on a basal lamina adjacent to a two to three cell thick muscle layer. The entire organ is surrounded by an adventitia of unusual morphology. Histochemical investigation demonstrated that DNAase, RNAase, and protease are present in the lumen, alkaline phosphatase is associated primarily with the microvilli, small amounts of acid phosphatase are concentrated in the midcell area of the columnar epithelium, and ATPase activity is localized in the muscle cells and just below the absorptive surface of the microvillous cells. The luminal contents and adventitial areas are Sudan Black B positive, all areas of the lumen and organ wall are PAS positive, the cell nuclei and amorphous masses in the lumen showed Feulgen staining, and large vesicles in the columnar cells were Oil Red O positive. Apparently, the spermatheca of B. glabrata is both a digestive and absorptive structure. Although this organ shares functional similarities with those found in opisthobranchs and terrestrial pulmonates, the epithelia of the spermatheca differ dramatically in these groups.
Characterization of the form and growth pattern of colonies in several freshwater bryozoans
Authors: Mukai Hideo , Fukushima Mariko , Jinbo Yoshie 
Published: February 2005

AbstractIn all species of phylactolaemates, an individual successively produces daughter buds. Individual daughters are designated, according to the order of appearance, as first bud, second bud, and so on. The first bud appears precociously, while the mother is a pear‐shaped vesicle. The idea of regarding a main bud, a duplicate bud, and an adventitious bud as a set is not tenable. In the budding region, the cystidal wall shows a constant wavy movement. In Plumatella colonies, branching occurs only when and where a bud of the second or higher order grows up to a zooid. A branch is composed of longitudinally arranged first zooids with the only exception being the most proximal one. The proportion of first zooids in a colony increases in the order of P. casmiana, P. emarginata, and P. repens. The frequency of branching, therefore, decreases in this order. The ancestrula germinated from the statoblast shows the highest activity of budding. The tendency that successively produced daughters of the ancestrula grow in alternate directions is most conspicuous in P. emarginata and least conspicuous in P. casmiana. Replacement budding occurs in these three species of Plumatella, but only under unfavorable culture conditions. The colony of Gelatinella toanensis is characterized by composite branches, each consisting of an axial branch composed of a series of first zooids and of stunted lateral branchlets. In Hyalinella punctata, multiple budding does not necessarily result in branching; zooids of different budding orders coexist in a branch. The genus Pectinatella comprises two species, P. gelatinosa and P. magnifica. Both produce massive colonies. In P. gelatinosa, the colony proper is sac‐like with the convex basal wall, and the polypides can retract with the digestive tracts straight. Each individual (except the ancestrula) of this species produces a pair of daughter buds which are located bilaterally relative to the median sagittal plane of the mother. A left bud produces its first bud to the right, and vice versa. In P. magnifica, the colony proper is very thin and flat. When polypides are retracted, the digestive tracts are folded characteristically. Based on these and other results, phylogenetic relationships among the phylactolaemates are discussed.
Fine structure and histochemistry of the freshly extruded and hardened spermatophore of the spiny lobster, Panulirus interruptus
Authors: Martin Gary G. , Herzig Chris , Narimatsu Glen 
Published: February 2005

AbstractFreshly extruded and hardened spermatophores of the spiny lobster, Panulirus interruptus, were compared using light and electron microscopy (EM). The spermatophore is composed of a sperm tube embedded in an acellular matrix. The sperm tube consists of tightly packed spherical cavities in an acellular material within which the sperm lie. The extruded spermatophore is white, soft, and sticky on all surfaces. The highly coiled sperm tube can be seen near the surface of the foot of the spermatophore, which is the side that will attach to the exoskeleton of the female. The opposite surface, the cap, will harden and darken after exposure to seawater. In the soft spermatophore, the matrix surrounding the sperm tube and extending from foot to cap is composed of small (2‐μm) granules embedded in a loose weave of filaments. In the hardened spermatophore, the matrix is composed of small (4‐μm) empty spheres. At the cap region the matrix darkens, and at the foot the granules dissolve to form a thick layer characterized by vertical striations. The structure of this spermatophore is compared to those spermatophores of other decapods that have been described at the EM level. The chemical composition and possible function(s) of the various components are discussed.
The spermatophore and its structural changes with time in the bursa copulatrix of the silkworm, Bombyx mori
Authors: Osanai Minoru , Kasuga Hiroko , Aigaki Toshiro 
Published: February 2005

AbstractThe bursa copulatrix of the silkmoth is filled with various secretions and seminal fluid transferred from the male reproductive system during mating. The contents of the bursa include a pearly body, spermatophragma, and spermatophore. The latter consists of a four‐layered wall, an inner and outer matrix, and a soft plug. The components of the spermatophore are all heterogeneous, since they are formed by the partially mixed, viscous streams of the male secretions. Apyrene spermatozoa and eupyrene bundles are present only in the inner matrix, but both the matrices are important sites of sperm maturation. After spermatophore formation, the basophilic regions and periodic acid‐Schiff (PAS)‐granules in both matrices gradually decrease with time. The PAS‐granules were identified as glycogen by α‐amylase treatment. The inner matrix containing sperm and the outer matrix decrease in volume and become concentrated near the neck of the spermatophore. Apyrene and eupyrene spermatozoa can move toward the ductus seminalis after their maturation. A large, beltlike space which does not stain remains at the periphery of the spermatophore. These structural changes of spermatophore contents seem to reflect metabolic reactions in the spermatophore as the reactor for sperm maturation.
Comparative study of the adrenergic innervation of the teleost gill
Authors: Donald John A. 
Published: February 2005

AbstractThe adrenergic innervation of structures in the gills of six teleost species was studied with catecholamine fluorescence histochemistry. The species studied were the following: sand flathead, Platycephalus bassensis and blue‐spot flathead Platycephalus caeuruleopunctatus (Platycephalidae); smooth toadfish, Tetractenos glaber (Tetraodontidae); Australian short‐finned eel, Anguilla australis (Anguillidae); river blackfish, Gadopsis marmoratus (Gadopsidae); and common carp Cyprinus carpio (Cyprinidae).In all species except C. carpio fluorescent components were observed in the branchial nerves in the gill arch.In the arterio‐arterial vascular pathway, the afferent and efferent branchial arteries were innervated only in Cyprinus. Fluorescent nerve fibres were found on afferent filamental arteries of all species except A. australis and on many afferent lamellar arterioles of all species except T. glaber. The secondary lamellae were devoid of fluorescent nerve fibres in all species. In Cyprinus and Anguilla, fluorescent nerve fibres were observed on occasional efferent lamellar arterioles. In Cyprinus, there was an additional innervation on the basal one‐third of the efferent filamental artery. The innervation of the arteriovenous vascular pathway was similar in all species. Fluorescent nerve fibres were found on nutritive arterioles, and in the core of each filament between the surface epithelium and the wall of the filament venous sinus.Since most of the adrenergic innervation was found on afferent vessels of the arterio‐arterial pathway, it is suggested that adrenergic nerves and circulating catecholamines may have distinct functions in the regulation of blood flow through the gills.
Antennal sensory organs in the millipede Eurypauropus ornatus: Fine structure of the flagella and globulus
Authors: Tichy Harald 
Published: February 2005

AbstractOn the antennal tip of Eurypauropus ornatus are 3 threadlike sensilla—the flagella, and a single spheroid sensillum—the globulus. Each of the 3 flagella is innervated by 2 groups of sensory cells. One group contains 4 cells, the other, 5. All cells of the “four group” and 3 of the “five group” are comprised of single cilia and unbranched dendrites which extend along the lumen of the flagellum. Two cells of the “five group” have double cilia and pairs of unbranched dendrites. One pair also enters the flagellum and the other pair terminates beneath the flagellar base to form a concentric array of lamellae. No pores are present in the cuticular wall.Eight sensory cells innervate the globulus. They are arranged in 3 groups, one triplet and 2 pairs, in addition to a single cell. The single cell contains a pair of cilia whose unbranched dendrites differentiate into tubular bodies that are inserted into the base of the globulus. Each of the other 7 sensory cells has a single cilium. Their unbranched dendrites penetrate into the globulus in 3 groups as described for the sensory cells. The dendrites in each group terminate in an individual pore channel at the globulus tip and completely fuse with the electron‐dense material that plugs the pore channel.Based on structural similarities to sensilla having known functions, it is probable that the flagella and the globulus are chemoreceptors, the former responding to odors, the latter sensitive to substances in aqueous solution.