bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trophoblastic invasion of the uterine epithelium in Calomys callosus (Rodentia, cricetidae)
Authors: Ferro Eloisa A. Vieira , Bevilacqua Estela 
Published: February 2005

AbstractImplantation 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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractFemales 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

AbstractThe 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

AbstractThis 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

AbstractThe 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

AbstractXenopus 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

AbstractPiranhas, 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

AbstractScanning 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

AbstractThe 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.
Ultrastructurally different muscle cell types in Eisenia foetida (Annelida, Oligochaeta)
Authors: Royuela Mar , Fraile Benito , García‐Anchuelo Rosa , Paniagua Ricardo 
Published: February 2005

AbstractMuscles in the body wall, intestinal wall, and contractile hemolymphatic vessels (pseudohearts) of an oligochaete anelid (Eisenia foetida) were studied by electron microscopy. The muscle cells in all locations, except for the outer layer of the pseudohearts, are variants of obliquely striated muscle cells. Cells comprising the circular layer of the body wall possess single, peripherally located myofibrils that occupy most of the cytoplasm and surround other cytoplasmic organelles. The nuclei of the cells lie peripherally to the myofibrils. The sarcomeres consist of thin and thick myofilaments that are arranged in parallel arrays. In one plane of view, the filaments appear to be oriented obliquely to Z bands. Thin myofilaments measure 5–6 nm in diameter. Thick myofilaments are fusiform in shape and their width decreases from their centers (40–45 nm) to their tips (23–25 nm). The thin/thick filament ratio in the A bands is 10. The Z bands consist of Z bars alternating with tubules of the sarcoplasmic reticulum. Subsarcolemmal electron‐dense plaques are found frequently. The cells forming the longitudinal layer of the body wall musculature are smaller than the cells in the circular layer and their thick filaments are smaller (31–33 nm centrally and 21–23 nm at the tips). Subsarcolemmal plaques are less numerous. The cells forming the heart wall inner layer, the large hemolymphatic vessels, and the intestinal wall are characterized by their large thick myofilaments (50–52 nm centrally and 27–28 nm at the tips) and abundance of mitochondria. The cells forming the outer muscular layer of the pseudohearts are smooth muscle cells. These cells are richer in thick filaments than vertebrate smooth muscle cells. They differ from obliquely striated muscle cells by possessing irregularly distributed electron‐dense bodies for filament anchorage rather than sarcomeres and Z bands and by displaying tubules of smooth endoplasmic reticulum among the bundles of myofilaments. © 1995 Wiley‐Liss, Inc.
Early embryonic development, including germ‐disk stage, in the theridiid spider Achaearanea japonica (Bös. et Str.)
Authors: Suzuki Hirohumi , Kondo Akio 
Published: February 2005

AbstractEarly embryonic development, from the first cleavage to the germ‐disk stage, in the theridiid spider Achaearanea japonica was examined by light and electron microscopy. The eggs are syncytial during the first four cleavages, and then invaginations of cell membranes fuse to generate the blastomeres at the sixteen‐nucleus stage. The cleavage pattern is a modified type of total cleavage. It appears that radial bundles of microtubules that radiate from the perinuclear cytoplasm may participate in the migration of cleavage nuclei for the formation of the blastoderm. The large yolk granules are sequestered by cell membranes from the blastomeres or blastoderm cells into the interior of the embryo together with various organelles and glycogen granules. Most of the blastoderm cells converge in the upper hemisphere to form the germ disk, whereas a few cells remain in the lower hemisphere. The embryo at the germ‐disk stage contains many spherical germ‐disk cells. Almost no large yolk granules are found in these cells, but the flat remaining cells each contain several large yolk granules. These remaining cells may preserve a flat shape to cover the surface of the embryo that does not include the germ disk. © 1995 Wiley‐Liss, Inc.