bluuebunny/crossref_metadata_2025 huggingface dataset:
Developmental changes in cytochrome oxidase histochemistry in the main and accessory olfactory bulbs of embryonic and neonatal garter snakes (Thamnophis sirtalis spp.)
Authors: Holtzman David A. , Gordon Evan , Halpern Mimi
Published: February 2005

Developmental studies examining the changes in oxidative metabolic activity are useful for understanding how and if the vomeronasal and olfactory systems respond to stimulation during embryogenesis. Garter snakes are good candidates for examining the potential functionality of the vomeronasal system in utero. In adult garter snakes, the vomeronasal system mediates many behaviors. Neonatal garter snakes exhibit these same behaviors, and the vomeronasal system has been shown to mediate feeding behavior in neonates. Using cytochrome oxidase histochemistry, we examined changes in the oxidative metabolic activity of main and accessory olfactory bulbs of embryonic and neonatal garter snakes (Thamnophis sirtalis sirtalis and T. s. parietalis). Cytochrome oxidase staining is greater in the accessory olfactory bulb than in the main olfactory bulb of embryonic garter snakes. However, neonates show no differences in the staining of the accessory and main olfactory bulbs, suggesting a change in the stimulation of the main olfactory bulb after birth. This is the first report of cytochrome oxidase histochemistry in reptiles and in the vomeronasal system of embryonic vertebrates. © 1993 Wiley‐Liss, Inc.
Spiral cleavage and cell position contribute to the specification of the dorsoventral axis in the embryo of the archaeogastropod Haliotis tuberculata
Authors: van den Biggelaar Jo A. M. , Faber Joop
Published: February 2005

In the embryo of Haliotis tuberculata spiral cleavage induces size differences between the quadrants in the 4‐cell embryo. These size differences, together with the formation of compact cell configurations, induce asymmetrical positions of equivalent cells in the 8‐ and 16‐cell embryo. The asymmetries in size and position influence the final specification of the dorsoventral asymmetry in the 32‐cell embryo, as well as formation of the mesentoblast. © 1994 Wiley‐Liss, Inc.
In vivo fluorescence imaging of the functional organization of trophotaenial placental cells of goodeid fishes
Authors: Kokkala I. , Wourms J. P.
Published: February 2005

Embryos of viviparous goodeid fishes undergo a 10 to 150 × increase in dry weight during gestation. Maternal nutrients are transferred across a trophotaenial placenta comprised of the ovarian lumenal epithelium and the trophotaeniae of the embryo. Trophotaeniae are externalized projections of the embryonic hindgut. Epithelial cells of the ribbon trophotaenia (Ameca splendens) resemble intestinal absorptive cells of suckling mammals and endocytose macromolecules. They possess an apical brush border, endocytotic complex, endosomal–lysosomal system, and apical and basal clusters of mitochondria. Cells of the rosette trophotaenia (Goodea atripinnis) lack an endocytotic apparatus, have small lysosomes, two mitochondrial clusters, and transport small molecules. Organelle‐specific fluorescent probes were employed to characterize the functional organization of the two types of trophotaenial cells. In A. splendens, Lucifer Yellow, a membrane‐impermeable tracer of vesicular transport, first appears in peripheral vesicles (15–45 sec), then passes into elongated tubular endosomes (1–3 min) and later appears in large central vacuoles (10–15 min). These vacuoles accumulate Acridine Orange, a classical probe for lysosomes, and have been shown to contain lysosomal enzymes. Endosomelysosome fusion was observed. In both A. splendens and G. atripinnis, Rhodamine 123 fluorescence was localized in two clusters of fine spots that corresponded to mitochondria. 4′,6‐diaminido‐2‐phenyl‐indole (DAPI) staining of nuclei established the positional relationships of cell organelles with respect to the nuclei. 3,3′‐dihexyloxacarbo‐cyanine iodide (DiOC6) revealed the perinuclear distribution of the endoplasmic reticulum. In order to compare in vivo fluorescence of Lucifer Yellow with previous ultrastructural observations, we employed fluorescence photoconversion and electron microscopy. © 1994 Wiley‐Liss, Inc.
Ontogenesis and ultrastructure of seminal vesicles of the catfish, Clarias gariepinus
Authors: Fishelson L. , van Vuren J. H. J. , Tyran A.
Published: February 2005

The ontogenesis and structural characteristics of the seminal vesicles in Clarias gariepinus (sharptooth catfish) were studied by light and electron microscopy and are described in detail. The seminal vesicles, beginning as simple protrusions from the vas efferentia, becomes more complex with age. Their distal ends become fingerlike and the bases form palm‐like extensions. Juvenile male organs do not reveal any signs of seminal vesicles although spermatogenic tissue is already well delineated. The developing gonads contain clusters of large cells, close to the sperm duct and cysts of the testis, from which seminal vesicles are formed. Secretory epithelium lines the tubules of the seminal vesicles and becomes columnar as the tissue matures. Electron micro‐graphs of these epithelial cells reveal two types of cells: opaque cells and cells with very vacuolized cytoplasm. Dense pinocytotic vesicles are present between the membranes of neighbouring seminal tubules and apical cell membranes facing the lumen. Maturation and onset of secretion by the secretory cells is accompanied by morphological changes. Protruding cylindrical cells become shortened, modified to cuboidal, rounded cells that send tubular extensions into the lumen. In the final stage of differentiation, only connective tissue membranes supporting the tubule walls remain intact. At the points of contact between the testis, seminal vesicles, and sperm duct, the epithelia of these organs often become confluent. The distal parts of the seminal vesicles, rarely contain sperm; during spawning sperm accumulated in the proximal tubules of the vesicles. © 1994 Wiley‐Liss, Inc.
Fine structure of laboratory cultured Distigma proteus and cytochemical localization of acid phosphatase
Authors: Yamaguich Toshiko , Roger Anderson O.
Published: February 2005

The phylogenetic relationship and origin of the euglenoids are controversial at present. It is not clear which of the extant genera may be most primitive, although Distigma proteus has been suggested as an early progenitor by some researchers. Scanning (SEM) and transmission (TEM) electron microscopic data were obtained in an effort to clarify some of the major taxonomic characteristics of this organism. SEM analyses of cells fixed during euglenoid movement (metaboly) show that the spirally arranged pellicular strips in the expanded regions of the organism have a lower pitch than those in the more constricted regions. This finding reveals the mechanical basis for euglenoid contortional movements. Mitochondria observed by TEM contain discoidal cristae, but some mitochondria are particularly large (e.g., 1.5 μm) and contain concentrically arranged, multiply layered cristae located deeper within the matrix, as in Khawkinea sp. Acid phosphatase reaction product is located in the cisternae and peripheral saccules throughout the Golgi stack and is regularly observed in the cisternae of the ER located beneath the pellicular ridges. Vacuoles varying in size, containing acid phosphatase reaction product, occur particularly near the periphery of the cell including the region surrounding the flagellar pouch. Occasional deposits of the reaction product within what appear to be membranous extrusions occur at the outer surface of the cell and may be secreted from sub‐pellicular organelles. © 1994 Wiley‐Liss, Inc.
Ultrastructure of hatchling chaetognaths (Ferosagitta hispida): Epithelial arrangement of the mesoderm and its phylogenetic implications
Authors: Shinn George L. , Roberts Michael E.
Published: February 2005

The trunk and tail mesoderm of hatchling chaetognaths consists of a simple myoepithelium containing four stereotypically arranged cell types, each matching in position a specific adult tissue. The trunk mesoderm includes lateral cells, longitudinal muscle cells, dorsal and ventral medial cells, and peri‐intestinal cells. These correspond, respectively, to the lateral fields, longitudinal body wall muscles, dorsal and ventral perimysial cells, and periintestinal muscles of adults. Because the developing intestine does not extend into the tail, tail cells equivalent in position to peri‐intestinal cells in the trunk are designated mesenterial cells. Numerous small spaces situated among the apices of hatchling mesodermal cells have the same position relative to surrounding cells as both the coelomic cavities of early embryos and the adult body cavities. We infer that these spaces in hatchlings expand and coalesce to form the definitive adult body cavities, and that these spaces and the adult body cavities derive from the embryonic coeloms. Because hatchlings lack mesenchymal mesoderm, we infer that all adult mesodermal tissues develop by elaboration of the coelomic lining of hatchlings. Because hatchlings lack cells corresponding to the squamous peritoneocytes overlying the body wall muscles of adults, we conclude that peritoneocytes are specialized adult cells that are not equivalent to cells of the embryonic coelomic lining. Finally, hatchlings contain a complete trunk/tail septum. This observation contradicts reports that this septum forms several days after hatching. It also weakens arguments that chaetognaths are bimeric rather than trimeric. © 1994 Wiley‐Liss, Inc.
On the shapes of leaves
Authors: Bird R. J. , Hoyle F.
Published: February 2005

The properties of a function G(x, y) of 2‐dimensional Cartesian coordinates x, y can be used to obtain complex shapes through a nonlinear iterative procedure. It is conjectured that at least some biological shapes are determined by this procedure, and those of leaves are considered as a test of the hypothesis. It is shown that this procedure will generate the shapes of even very complicated leaves such as those of the holly tree to a considerable degree of accuracy. Certain issues of evolutionary biology appear in our view in a clearer light according to this procedure, and these are discussed towards the end of the paper. © 1994 Wiley‐Liss, Inc.
Pectoralis muscle morphology in the little brown bat, Myotis lucifugus: A non‐convergence with birds
Authors: Meyers Ron A. , Hermanson John W.
Published: February 2005

Recent studies of muscle architecture demonstrate that many mammalian muscles are composed of short, interdigitating fibers. In addition, the avian pectoralis, a muscle capable of producing high frequency oscillations has been shown to possess a serially arranged pattern of muscle endplate in all sizes of birds studied. The pectoralis muscle of the little brown bat, Myotis lucifugus (Chiroptera: Vespertilionidae), is composed of fairly uniform fibers that span the length of the muscle and is characterized by a zone of motor endplates within the middle third of the muscle. The homogeneous fiber architecture of the bat pectoralis muscle is in contrast to the serial arrangement of endplates (and presumably muscle muscle fibers) in the avian pectoralis in species equivalent in size to Myotis. The short fiber organization and motor endplate pattern observed in most birds is thus not a requisite design for flying vertebrates. © 1994 Wiley‐Liss, Inc.
Ultrastructure of the spermatozoa of five species of South African bivalves (Mollusca), and an examination of early spermatogenesis
Authors: Reunov A. A. , Hodgson A. N.
Published: February 2005

Transmission electron microscopy of the spermatozoa of five species from three families of bivalves has shown that each species has a sperm with unique morphology. However, the morphology of the acrosomes of each species is typical of the subclass of bivalve to which they belong. An examination of spermatogenesis in the five species, along with a re‐examination of material from six other species of bivalves, has revealed that pre‐spermiogenic cells possess flagella. In addition, acrosome formation begins in the spermatocytes with the formation of proacrosomal vesicles in the Golgi body. During spermiogenesis the proacrosomal vesicles coalesce at the presumptive posterior of the spermatid, with a larger vesicle produced by the Golgi body. The single acrosomal vesicle eventually migrates to the anterior of the spermatid where it assumes its mature form. © 1994 Wiley‐Liss, Inc.
Morphological study of nerve endings in jaw muscles of post‐hatching American alligators (Alligator mississippiensis)
Authors: Sato Iwao , Shimada Kazuyki , Ezure Hiromitsu , Murakami Gen , Sato Tooru
Published: February 2005

Two months after hatching, the fibers of the jaw muscles of the American alligator are associated with three types of nerve terminals namely, plates, simple plates, and grape endings. Simple plate endings are mainly observed on the small muscle fibers. Grape‐type endings are found on muscle fibers that resemble the tonic fibers of garter snakes (Hess, Am. J. Anat., '63). Most terminals are plate endings and account for 53.7–74.7% of terminals per muscle. Fibers with grape‐type endings were found in all the jaw muscles studied; they lack well organized T‐systems, M‐lines, and post‐junctional sarcolemmal folds, as well as irregularly distributed small of fibrils, and zigzag Z‐lines.

The properties of nerve endings of the American alligator indicate that M. depressor mandibulae, M. pseudotemporalis, and M. pterygoideus posterior have primary roles in jaw movements. M. pterygoideus anterior and M. intramandibularis contribute mainly to postural adjustments of the jaws. The multiplicity of nerve terminals in the jaw muscles of American alligators contrasts with the simple movements of their jaws. © 1994 Wiley‐Liss, Inc.
Sperm storage in male elasmobranchs: A description and survey
Authors: Pratt Harold L. , Tanaka Sho
Published: February 2005

Two basic types of spermatozoan aggregates, spermatophores and spermatozeugmata, found in 14 different species of sharks, one species of skate, and one species of chimaera (holocephalan), were investigated using light and scanning electron microscopy. Spermatophores, aggregates (usually 1,000–6,000 μm in diameter and larger) of randomly clumped sperm embedded in and surrounded by an eosinophilic matrix, were found in Alopias superciliosus, Odontaspis taurus, Carcharodon carcharias, Isurus oxyrinchus, and Lamna nasus. Three types of spermatozeugmata, sperm structures without a surrounding capsule or matrix, are described. The first, clumps of 60–200 sperm unbound in a supporting matrix, are found in Squalus acanthias and Hydrolagus colliei. In the second type, single‐layered spheres are formed of sperm clumps with the sperm heads bound in a common supporting matrix. These are found in Carcharhinus limbatus and Carcharhinus plumbeus. The third type of spermatozeugmata are large multilayered, compound structures formed by the accretion of several single‐layered aggregates. These multilayered structures characteristically are found in Carcharhinus falciformis, C. limbatus, Carcharhinus obscurus, C. plumbeus, Carcharhinus porosus, Prionace gluaca, Rhizoprionodon terraenovae, and Sphyrna lewini. Sperm aggregates of all types are stored between the septa and in the lumen of the terminal ampulla of the epididymis. In their various forms they are the final product of the mature male elasmobranch reproductive tract. In a male with mature claspers, the presence of sperm aggregates is a more reliable indicator of maturity and sexual activity than is clasper condition alone. © 1994 Wiley‐Liss, Inc.
Microdissectional investigation of the nephrons in some fishes, amphibians, and reptiles inhabiting different environment
Authors: Gambaryan Stepan P.
Published: February 2005

The structure of nephrons in 83 species of fishes, amphibians, and reptiles was investigated by microdissection. Glomerular diameter, nephron length, length of nephron segments, and the ratios between glomerular size and nephron length are presented. In diifferent groups of fishes (Elasmobranchii, Acipenseridae, Teleostei), the adaptation to freshwater or seawater environment may lead to diverse changes of nephron structure. The kidneys of euryhaline teleosts capable of living in fresh water may be aglomerular, as are those of some marine fishes. In contrast, the diameter of glomeruli in some marine fishes is larger than in true freshwater fishes. In amphibians, the adaptation to freshwater environment, as in teleost fishes, has led to different changes of nephron structure. The size of glomeruli in freshwater reptiles is larger in comparison to terrestrial animals, and the distal tubule in desert and freshwater reptiles is longer than in nondesert species. This probably reflects the adaptive changes of the reptilian nephron to freshwater and desert environments. The results of this study show that the nephron structure of lower vertebrates is predominantly determined by the different environments they occupy rather than by progressive changes within the vertebrate sequence. © 1994 Wiley‐Liss, Inc.
Histological study of odontogenesis in the pharyngeal jaws of Trachinotus teraia (Cuvier et valenciennes, 1832) (Osteichthyes, Teleostei, Carangidae)
Authors: Francillon‐Vieillot Hélène , Trébaol Loïc , Meunier François J. , Slembrouck Jacques
Published: February 2005

A histomorphological study of the development of the pharyngeal jaws in the Carangid fish Trachinotus teraia shows that they transform progressively from tiny organs with sharp superficial teeth, to thick ones with rounded teeth embedded in bony tissue. The morphological transformations take place simultaneously with a shift to a diet based on molluscs.

Though odontogenesis takes place deep in the pharyngeal jaws, at all developmental stages, pharyngeal epithelium participates to the formation of teeth. Long epithelial strands penetrate in the depth of the bony jaw and here induce differentiation of “bell organs.” As the young teeth migrate passively toward the occlusal surface, while the jaw grows, the pharyngeal jaws of Trachinotus teraia almost behave like the “coalesced” teeth of the Tetraodontidae with respect to the morphogenetic processes of their growth. The developmental phenotypic plasticity of the pharyngeal jaws of Trachinotus teraia then may be compared to that of various mollusicivore cichlids. © 1994 Wiley‐Liss, Inc.
Cellular organization of the dome sensillum: A presumed chemoreceptor in Gammarus setosus (Gammaridea: Amphipoda)
Authors: Steele V. J.
Published: February 2005

A previously unknown type of sensillum with a thin cuticular dome and two pairs of pores is described in the amphipod Gammarus setosus. There is only one dome sensillum on each interantennal lobe of the head. The receptor is innervated by two sensory dendrites that bifurcate into two pairs of 9 + 0 cilia, concentrically enclosed by four auxiliary cells—two thecogen, one trichogen, and one tormogen and surrounded by a cluster of accessory cells. The ciliary regions are contained in small inner lymph cavities. The outer segments are sheathed by the apical extensions of the thecogen cells, are looped inside the outer lymph cavity, and come in close contact with lipid spheroids inside the dome. The basal bodies consist of microtubule doublets, which extend into the distal segments where they are interspersed with singlets. The nodal inner dendritic segments join the ventral suspension cord of the organ of Bellonci and enter its ganglion. The application of colloidal lanthanum resulted in intraciliary lanthanum deposits. The dome sensilla are presumed to be chemosensory because their cellular plan has similarities to that of some known olfactory and pheromone‐sensitive sensilla in decapod crustaceans and insects. © 1994 Wiley‐Liss, Inc.
Embryonic development of the jumping bristletail Pedetonutus unimaculatus Machida, with special reference to embryonic membranes (Hexapoda: Microcoryphia, Machilidae)
Authors: Machida Ryuichiro , Nagashima Takayuki , Ando Hiroshi
Published: February 2005

In the machilid Pedetonutus unimaculatus, a germ disc is formed by the aggregation and proliferation of cells within a broadly defined embryonic area. Cells adjacent to the embryonic area form the serosal fold that grows beneath the embryo. Then the embryonic margin is extended to form a cell layer or amnion that lies between the embryo and serosal fold. Thus, an amnioserosal fold is formed by the addition of the amnion to the serosal fold. Serosal cells cover the entire surface of the egg and begin to secrete a serosal cuticle. Soon the amnioserosal fold is withdrawn, and the embryo is exposed to the egg surface. The spreading amnion replaces the serosal cells that finally degenerate through the formation of a secondary dorsal organ. In the areas of amnion anterior and lateral to the embryo, yolk folds form and encompass the embryo. The amnion is a provisional dorsal closure and never participates in the formation of the definitive one.

The amnioserosal fold of the Microcoryphia appears to have the functional role of secreting a serosal cuticle beneath the embryo. This fold of the Microcoryphia may be regarded as an ancestral form of the amnioserosal folds of the Thysanura‐Pterygota. the yolk folds may appear to be passive transformation of the yolk mass linked to positioning of the growing embryo within the egg. There is no evidence that the yolk folds and the cavity appearing between them in the Microcoryphia are homologous to the amnioserosal fold and amniotic cavity in the Thysanura‐Pterygota. The yolk folds appear to be one of the embryological autapomorphies in the Microcoryphia. © 1994 Wiley‐Liss, Inc.
Palmar and plantar pads and flexion creases of the rat (Rattus norvegicus)
Authors: Kimura Sumiko , Schaumann Blanka A. , Plato Chris C.
Published: February 2005

The recent detection of dermal ridge configurations on the volar pads of the rat (Rattus norvegicus) has created opportunities for experimental studies of dermatoglyphics. In the present work, the palmar and plantar surfaces of the rat were studied to establish the feasibility of comparative rat and human dermatoglyphic investigations. The studied features included the volar pads and flexion creases. The number and location of the palmar and plantar pads in the rat were found to be similar to those of humans. The exception was a previously unrecognized small pad on the palms and soles of the rat, located on the radial and tibial side, respectively, of the proximal component of the first interdigital pad. This pad has no parallel in human embryos. Rats were found to have flexion creases in the non‐pad areas between the neighboring pads, similar in location and appearance to those of humans. Unlike humans, however, rats also have boundary creases, separating the pad and non‐pad areas. The marked similarities in the morphology of the volar areas between rats and humans make the rat ideally suitable for experimental studies of dermatoglyphics and flexion creases. Results of such studies should be applicable to human developmental dermatoglyphics, including those pertaining to medical disorders. © 1994 Wiley‐Liss, Inc.
Morphological changes in external and internal feeding structures during the transition phyllosoma‐puerulus‐juvenile in the Western Rock Lobster (Panulirus cygnus, Decapoda: Palinuridae)
Authors: Lemmens J. W. T. J. , Knott B.
Published: February 2005

External and internal feeding structures of the pelagic final phyllosoma, the transitional puerulus, and the benthic juvenile Western Rock Lobster, Panulirus cygnus, were studied by means of scanning electron microscopy. The study revealed that the external feeding structures of phyllosomata are well equipped for capture and mastication of food. The foregut, however, is not clearly divided into pyloric and cardiac regions and a gastric mill is absent, although a comb row and gland filter are present. Juveniles, on the other hand, have a well‐developed gastric mill and gastric teeth, and a cardiopyloric valve separates the foregut into cardiac and pyloric regions. External mouthparts of juveniles are suitable for mastication of solid food particles and bear numerous setae. In contrast, external mouthparts of pueruli are largely non‐setose. Furthermore, although the foregut is differentiated into pyloric and gastric regions and a gland filter and comb row are present, a functional gastric mill is absent during the puerulus stage. Absence of such structures indicates that the puerulus may be a non‐feeding stage. It is postulated that absence of (or reduced) feeding may be a response to an increased risk of predation rather than a result of the considerable morphological changes taking place during the transition from a planktonic to a benthic lifestyle, as has been previously proposed. © 1994 Wiley‐Liss, Inc.
Microscopic anatomy and ultrastructure of the introvert of Priapulus caudatus and P. tuberculatospinosus (Priapulida)
Authors: Storch V. , Higgins R. P. , Malakhov V. V. , Adrianov A. V.
Published: February 2005

Introverts of Priapulus caudatus and P. tuberculatospinosus bear 25 rows of scalids, as well as 8 spines and scattered papillae in the region the circumoral lip. These, as well as the first ring of pharyngeal teeth in P. tuberculatospinosus, are sensory organs. Although superficially they differ between species, they are all characterized by apical and/or subapical openings which are located on tiny cuticular tubules. All sensory organs contain cilia bearing bipolar receptor cells. The 8 sensory spines situated between the circumoral area and the beginning of the scalids are ultrastructurally similar to the scalids. The introvert and pharyngeal body walls, and associated muscles are described. © 1994 Wiley‐Liss, Inc.
Comparative study of lower pharyngeal jaw structure in two phenotypes of Astatoreochromis alluaudi (teleostei: Cichlidae)
Authors: Huysseune A. , Sire J.‐Y. , Meunier F. J.
Published: February 2005

The potentially molluscivorous East‐African cichlid Astatoreochromis alluaudi is known to exhibit phenotypic plasticity in its pharyngeal jaw apparatus. We examined wild‐caught (snail‐eating) fish and specimens experimentally reared on soft food for differences in bone structure in their lower pharyngeal jaw (LPJ). The LPJ is built up of two halves, each of which consists of four structural units: a bony dentigerous, sutural and cortical plate, surrounding a medullary cavity containing sparse bone. Histomorphometric data and associated statistical analysis on serial microradiographs through the posterior third region of the LPJ, where crushing forces are assumed to be the highest, reveal differing growth trajectories: (1) compensating for fish size (standard length) the LPJ grows to a significantly larger size and volume in snail‐eating specimens, (2) all structural units distinguished contribute to the volume increase of the LPJ in the hard versus the soft phenotype, and (3) the bone volume fraction in each of the units keeps pace with the growth of the unit proper, indicating that porosity does not change on one growth trajectory or from one phenotype to another. In addition, morphological observations show in hard food specimens: (1) the development of a structurally different bony layer along the inner side of the cortical plate, and (2) a reinforcement of the medullary cavity in the form of oriented trabeculae. Both are interpreted as a consolidation of the medullary cavity to resist the compressive forces exerted when hard food particles (mollusc shells) are crushed. © 1994 Wiley‐Liss, Inc.
Trophoblastic invasion of the uterine epithelium in Calomys callosus (Rodentia, cricetidae)
Authors: Ferro Eloisa A. Vieira , Bevilacqua Estela
Published: February 2005

Implantation sites in the uterus of the cricetid rodent Calomys callosus were examined by light and electron microscopy at several points during day 4 of pregnancy to determine the changes occurring in the trophoblast and epithelial cells during the early blastocyst‐endometrial relationship, particularly the epithelial removal phase. By morning, the blastocysts had already lodged in the antimesometrial region of the uterine crypts and the embryo‐maternal interaction was limited to sparse contacts between the epithelial microvilli and the trophoblast surface. A few dense and altered epithelial cells were present. Three zones could be distinguished in the stromal region. In the subepithelial area, the stromal cells showed features similar to those found in other rodents during the early decidualization process. Effective epithelial invasion by the trophoblast occurred only in the evening, although at noon, apposition and attachment phases were identifiable. During invasion, the trophoblast processes were first seen insinuating between the epithelial cells, projecting towards the basal lamina, and finally replacing these cells. The epithelial cells in contact with the invading trophoblast exhibited severe disorganization similar to that found during the process of cell death by apoptosis. The removal of such cells occurred by trophoblast phagocytosis. Once in contact with the basal lamina, the trophoblast rapidly spread out both mesometrially and antimesometrially, phagocytosing the remaining epithelial cells. Trophoblast processes were also seen penetrating the basal lamina. Given that the epithelium breached and phagocytosed by the trophoblast habitually displays degenerative characteristics, we consider the mechanisms that might be involved in epithelial cell death and in the removal of the uterine epithelium, and the participation of the trophoblast in both these events. © 1994 Wiley‐Liss, Inc.
Complex tibial organs in fore‐, mid‐, and hindlegs of the bushcricket Gampsocleis gratiosa (Tettigoniidae): Comparison of morphology of the organs
Authors: Lin Yuzhen , Rössler Wolfgang , Kalmring Klaus
Published: February 2005

The structure of the complex tibial organs in the fore‐, mid‐, and hindlegs of the East Asian bushcricket Gampsocleis gratiosa (Tettigoniidae, Decticinae) is described comparatively. In each leg the tibial organs consist of three scolopale organs: the subgenual organ, the intermediate organ, and the crista acoustica. Only in the forelegs are the tibial organs differentiated as tympanal organs, and sound transmitting structures (acoustic trachea, tympana, and tympanal covers) are present. The morphology of the tracheae in the mid‐ and hindlegs is significantly different from that found in the forelegs. The number of scolopidia in the subgenual organ is highest in the midleg and lowest in the foreleg; in the intermediate organ the number is also highest in the midleg, and the fore‐ and hindleg contain 40% fewer scolopidia. In the crista acoustica, the number of scolopidia decreases from, the fore‐ to the mid‐ and hindlegs. The morphology and the dimensions of the scolopidia and the attachment structures within the crista acoustica of the mid‐ and hindlegs differ strongly from those in the foreleg. The results indicate that, in addition to the presence of a sound transmitting system, the specific differentiations within the crista acoustica are important for the high auditory sensitivity of the tibial organs in the forelegs. © 1994 Wiley‐Liss, Inc.
Morphology of shells from viable and nonviable eggs of the chinese alligator (Alligator sinensis)
Authors: Wink Carole S. , Elsey Ruth M.
Published: February 2005

The morphology of eggshells from hatched eggs of captive Chinese alligators (Alligator sinensis) was compared with that of shells from eggs with early embryonic death and with the morphology of eggshells from the American alligator (Alligator mississipiensisis). Pieces of shells were examined in the scanning electron microscope. Parameters examined included: numbers of open pores on the outer surfaces, total shell thickness, and thickness of the outer densely calcified and inner mammillary layers. Results indicate that shells from Chinese and American alligator eggs with early embryonic death have a thicker outer densely calcified layer than do shells from hatched eggs or full‐term embryos. Also, eggshells from Chinese alligator eggs with dead embryos have fewer open pores on the outer surface than do shells from hatched eggs, as has been reported earlier for the American alligator (Wink et al., '90). © 1994 Wiley‐Liss, Inc.
Detection of sugar residues in lizard tooth germs (Liolaemus gravenhorsti) using lectin histochemistry
Authors: Lemus D. , Cabello R. , Lemus R. , Soto M. , Fuenzalida M.
Published: February 2005

The appearance, cellular distribution, and changes of sugar residues during tooth development in adults of the polyphyodont, Liolaemus gravenhorsti, were investigated by using horseradish–peroxidase–conjugate lectins (lectin–HRP). With Con A (Canavalia ensiformis), the ameloblasts (late bell stage) show granular supranuclear positivity and also at the Golgi zone and on their tomes process. Reactivity also appears at the apical surface of the odontoblasts and odontoblastic process. With WGA (Triticum vulgaris), the tooth germs (late bell stage) show cytoplasmatic granular positivity in the ameloblast cells, Golgi regions, and in a lesser extent of the cytoplasm. Also, the apical surface and the odontoblastic process react. WGA reaction is depressed following sialidase treatment.

The significance in tooth germs of α‐D‐mannose, α‐D‐glucose as well as β‐D‐N‐acetylglucosamine and sialic acid is difficult to ascertain. These oligosaccharides may have some significance in odontogenesis. In fact, Con A‐HRP‐ and WGA‐HRP‐binding components in ameloblasts and odontoblasts may be functionally related to molecules that are thought to contribute to odontogenesis in lizards. © 1994 Wiley‐Liss, Inc.
Morphology and evolutionary implications of the annual cycle of secretion and sperm storage in spermathecae of the salamander Ambystoma opacum (Amphibia: Ambystomatidae)
Authors: Sever David M. , Krenz John D. , Johnson Kristin M. , Rania Lisa C.
Published: February 2005

Females of the marbled salamander, Ambystoma opacum, store sperm in exocrine glands called spermathecae in the roof of the cloaca. Eggs are fertilized by sperm released from the spermathecae during oviposition. Some sperm remain in the spermathecae following oviposition, but these sperm degenerate within a month and none persists more than 6 mo after oviposition. Thus, sperm storage between successive breeding seasons does not occur. Apical secretory vaculoes are abundant during the fall mating season and contain a substance that is alcian blue+ at pH 2.5. Production of secretory vacuoles decreases markedly after oviposition, and the glands are inactive by the summer months. Ambystoma opacum is a terrestrial breeder, and some mating occurs prior to arrival at pond basins where oviposition occurs. Mating prior to arrival at the ovipository site may prolong the breeding season, leading to fitness implications for both males and females. Females have opportunities for more matings, and the possibilities for sperm competition in the spermathecae are enhanced. © 1995 Wiley‐Liss, Inc.
Anatomy of neurons crossing the tritocerebral commissures of the cockroach Periplaneta americana (Blattaria)
Authors: Gundel Matthias , Penzlin Heinz
Published: February 2005

The neuronal connections of the tritocerebral commissures of Periplaneta americana were studied in the brain‐suboesophageal ganglion complex and the stomatogastric nervous system by means of heavy metal iontophoresis through cut nerve ends followed by silver intensification. The tritocerebral commissure 1 (Tc1) contains mainly the processes of the subpharyngeal nerve (Spn) whose neurons are located in both tritocerebral lobes and in the frontal ganglion. Some neurons of the frontal ganglion project through the Tc1 to the contralateral tritocerebrum. A few fibers in this commissure were observed projecting to the protocerebrum and the suboesophageal ganglion. There are tritocerebral neurons which pass through the Tc1 or the tritocerebral commissure 2 (Tc2) and extend on into the stomatogastric nervous system. One axon of a descending gaint neuron appears in the Tc2. This neuron lies in the tritocerebrum and connects the brain to the contralateral side of the ventral nerve cord. In addition, sensory fibers of the labral nerve (Ln) traverse both commissures to the opposite tritocerebrum. The anatomical and physiological relevance of the identified neuronal pathways is discussed. © 1995 Wiley‐Liss, Inc.
Skeletal morphogenesis in the urodele skull: III. Effect of hormone dosage in TH‐induced remodeling
Authors: Rose Christopher Stewart
Published: February 2005

This study examines the dosage dependency of thyroid hormone (TH)‐mediated remodelling in the cranial skeleton of the hemidactyliine plethodontid urodele, Eurycea bislineata. One set of experiments quantifies morphogenetic responses in 21 tissues for four size‐age classes of larvae immersed in four different T4 concentrations. A second set varies both the period and concentration of T4 treatment to evaluate the effect of different TH profiles on adult tissue shape. The tissues surveyed in this study exhibit a 100‐fold range in TH sensitivity. Those in regressive morphogenesis have tissue‐specific sensitivities which correlate with the timing of their remodelling in natural development: bone resorption is more sentitive than cartilage resorption and is initiated earlier in metamorphosis. In contrast, the TH sensitivities of tissues in progressive morphogenesis vary within each tissue type and even within some tissues, and they do not correlate with timing in natural development. Some explanation for this discrepancy is offered by the constant spatial and temporal relationships between nasal cartilage and dermal bone, which suggest that some TH‐mediated ossification may additionally require induction by cartilage. Also, the failure of nasolacrimal duct morphogenesis at all but the lowest dosage correlates with the inductdion of integumentary changes that may preclude duct formation. Variable T4 treatments produce no effect upon the adult skull, other than loss of the nasolacrimal duct and/or foramen. These results have two developmental implicatons. First, the dosage dependencies of the nasolacrimal duct, ossification sequences, and cranial remodelling patterns all support a TH profile with exceptionally low levels at larval stages and at least a 100‐fold increase at metamorphosis. Second, a small change in the rate of TH activity has the potential to effect a large‐scale rearranggement and restructuring of TH‐dependent remodelling. The lack of such transformations in metamorphic plethodontids suggests that TH activity is highly conserved in this group. © 1995 Wiley‐Liss, Inc.
Cephalic morphology of the honey possum, Tarsipes rostratus (Marsupialia: Tarsipedidae); an obligate nectarivore
Authors: Rosenberg H. I. , Richardson K. C.
Published: February 2005

The sharply tapering skull of the honey possum is delicately constructed and has only a few, minute teeth; its mandible is reduced to a thin, flexible rod. The mandibular fossa has been diplaced caudally to the caudomedial corner of the squamosal. Head skeletons of the feathertail glider and western pygmy‐possum, omnivores that are closely related to the honey possum, bear greater resemblance to the distantly related carnivorous fat‐tailed dunnart than to the honey possum.

Selected muscles associated with the jaws, hyoid, and tongue of these four mouse‐sized (9–22 g) marsupials are described for the first time. The honey possum is characterized by a greatly reduced temporalis that is almost completely hidden by the eye. Its digastric consists of a single belly that inserts onto the caudal margin of the mylohyoid. The lateral pterygoid is relatively long as it extends caudally to insert onto the elongated mandible. The stylohyoid originates high up on the caudal surface of the tympanic bulla; it curves around the caudal and ventral surfaces of the bulla to reach the basihyoid. The insertion of the genioglossus is restricted to the caudal quarter of the tongue. Homologous muscles of the feathertail glider and western pygmy‐possum are more similar to those of the fat‐tailed dunnart. In addition to the very different musculoskeletal system, the honey possum has an unusual tongue that tapers to a fine point. © 1995 Wiley‐Liss, Inc.
Development of the interphotoreceptor matrix in Xenopus laevis
Authors: Lahiri Devjani , Landers Robert A. , Hollyfield Joe G.
Published: February 2005

Xenopus laevis interphotoreceptor matrix (IPM) contains a relatively aqueous insoluble wheat germ agglutinin (WGA)‐binding component containing unidentifiied sialoglycoconjugates (Wood et al [1984] J. Comp. Neurol. 228:299–307). The appearance of WGA‐binding macromolecules in the IPM was assessed during late embryonic stages (32–45) and in retinal rudiment cultures, using lectin cyutochemistry and Western blotting techniques. Metabolic labeling of the neural retina versus retinal pigment epithelium (RPE)‐choroid of juvenile Xenopus with 35S‐MET was also evaluated in vivo and in vitro. Lectin cytochemistry of eyes from developmental stages 32–42 demonstrated distinct WGA‐ferritin‐binding sites on the developing outer segment membranes and in the IPM compartment. At stages 44–46 extensive WGA‐binding domains were present as an extracellular network with other randomly scattered domains near the retinal pigment epithelium. Retinal rudiments from stage 32–33 were isolated and allowed to differentiate in hanging drop culture (Hollyfield and Witkowsky [1974] J. Exp. Zool. 189:357–377) with or without an iinvesting pigment epithelium. Cultures developing with RPE exhibited an elaborate IPM with an anastomosing meshwork of WGA‐ferritin binding sites. In the absence of RPE only limited amoutns of binding restricted to the immediate vicinity of the developing photoreceptor outer segement membranes was observed. When Western blots were probed with WGA‐HRP, stage 32–45 retinas demonstrated a major WGA‐binding band of 126 kD. Similar amounts of WGA‐binding macromolecules were synthesized in preparations cultured in the presence or absence of the investing RPE. During development the major WGA‐binding component is a 126‐kD protein. Equivalent synthesis of this protein in the presence and absence of RPE suggests that the PE is not required for synthesis of this 126‐kD component. These results suggest that the retina is the primary site of synthesis of the WGA‐binding components of the Xenopus IPM, whereas the PE plays a principal role in their assembly and organization. © 1995 Wiley‐Liss, Inc.
Allometry and developmental integration of body growth in a piranha, Pygocentrus nattereri (Teleostei: Ostariophysi)
Authors: Zelditch Miriam Leah , Fink William L.
Published: February 2005

Piranhas, like many teleosts, change their diets on both ontogenetic and phylogenetic time scales. Prior studies have suggested that pervasive morphological changes in body form on a phylogenetic time scale may be related to changes in diet, but previous reports have found little shape change in piranhas on an ontogenetic time scale. We re‐examine the post‐transformational allometry of body form in one piranha, Pygocentrus nattereri (Kner), using the method of thin‐plate splines decomposed by their partial warps. We find substantial evidence of allometry, primarily elongation of the mid‐body relative to the more anterior and posterior regions, elongation of the postorbital and nape regions relative to the more anterior head and posterior body, and deepening of the head relative to the body. In addition to these pervasive changes throughout the body, there are some that are more localized, especially elongation of the postorbital region relative to eye diameter and snout, and an even more localized elongation of the snout relative to eye diameter. Initial dietary transitions are associated with changes in head and jaw proportions, but rates of shape change decelerate through growth, so that the final transition to a diet increasingly dominated by small whole fish appears associated with change largely in overall body size. © 1995 Wiley‐Liss, Inc.
Histological and functional changes of oviductal endometrium during seasonal reproductive cycle of the soft‐shelled turtle, Lissemys punctata punctata
Authors: Sarkar Supriti , Sarkar N. K. , Maiti B. R.
Published: February 2005

Scanning electron and light microscopic studies reveal significant changes in the endometrial histophysiology of the soft‐shelled turtle Lissemys punctata punctata during its seasonal reproductive cycle. Scanning electron microscopy shows the entire oviductal mucosa to be only slightly folded throughout the non‐breeding period (regressive, quiescent, preparatory and recrudescent phases). With the onset of the breeding phase, the mucosa shows extensive foldings and convolutions. The adluminal mucosal lining of the non‐breeding oviduct is covered by a tall, dense ciliary bed, interrupted by a few fissures and pits. Microvilli‐bordered secretory cells only appear amongst the ciliated cells during the breeding phase.

Light microscopic study reveals the mucosal epithelium to be low pseudostratified columnar throghout the non‐breeding period. The breeding epithelium, on the other hand, is tall columnar and does contain clearly distinguishable ciliated and secretory cell types. Submucosal glands only appear for a short period (ovulation to oviposition) in the infundibulum and isthmus regions of the oviduct, but these glands are observed throughout the reproductive cycle in the tube and uterus. The secretory activity of the submucosal glands, which occur only during the peak breeding stages, involves release of vesicular secretory materials through the gland openings. The stimulated endometrial histology and activity during the breeding phase coincide with increased levels of serum estrogen and progesterone, whereas the regressed and inactive state of the endometrium is paralleled by decreased levels of these ovarian steroids. © 1995 Wiley‐Liss, Inc.
Structure of ovaries in ensign scale insects, the most primitive representatives of Coccomorpha (Insecta, Hemiptera)
Authors: Szklarzewicz Teresa , Biliński Szczepan M.
Published: February 2005

The ovaries of Orthezia urticae and Newsteadia floccosa are paired and composed of numerous short ovarioles. Each ovariole consists of an anterior trophic chamber and a posterior vitellarium that contains one developing oocyte. The trophic chamber contains large nurse cells (trophocytes) and arrested oocytes. The total number of germ cells per ovariole (i.e., cluster) is variable, but it is always higher than 32 and less than 64. This suggests that five successive mitotic cycles of a cystoblast plus additional divisions of individual cells are responsible for the generation of the cluster. Cells of the trophic chamber maintain contact with the oocyte via a relatively broad nutritive cord. The trophic chamber and oocyte are surrounded by somatic cells that constitute the inner epithelial sheath around the former and the follicular epithelium around the latter. Anagenesis of hemipteran ovarioles is discussed in relation to the findings presented. © 1995 Wiley‐Liss, Inc.