bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrastructure of spermatogenesis in the hawaiian red lobster, Enoplometopus occidentalis (randall)
Authors: Haley Samuel R. 
Published: February 2005

AbstractElectron microscopy of spermatogenesis in the Hawaiian red lobster, Enoplometopus occidentalis (Randall), has revealed unusual activity within membranous organelles. Mitochondria‐like bodies (MLB‐1) seen first in spermatogonia appear in primary spermatocytes to swell and fuse as the cytoplasm develops annulate lamellae and other membrane complexes. In early spermatids, annulate lamellae derived from the nuclear envelope contribute to development of an extensive lamellar membrane complex within the cytoplasm, the forerunner of the lamellar region. Other mitochondria‐like bodies (MLB‐2) originate from this membrane complex and contribute to formation of the acrosomal vesicle, which assumes a semicrystalline organization composed of bundles of tubular components slightly larger in diameter than microtubules. An amorphous subacrosomal material may be equivalent to the acrosomal tubule of other decapod spermatozoa. Centrioles at the base of the acrosome produce microtubules that extend between the membranes of the lamellar region distally through the uncondensed nucleus as the cores of the three radial arms of this aflagellate spermatozoon. Nuclear material and electron‐dense lamellar region membranes project into the bases of these radial arms. Nuclear and plasma membranes are fused except where the acrosome lies between them. Of the mitochondria‐like bodies, the MLB‐1 do not persist into spermiogenesis, and the MLB‐2 are derived from the lamellar region. This is in contrast with other reported studies of lobster spermatozoon ultrastructure.
Histological and cytological structure of the gastrointestinal tract of the luderick, Girella tricuspidata (pisces, kyphosidae), in relation to diet
Authors: Anderson Trevor A. 
Published: February 2005

AbstractThe gastrointestinal tract of Girella tricuspidata, an herbivorous teleost, is differentiated into esophagus, stomach, pyloric caeca, intestine, and rectum. The mucosa of the esophagus consists almost entirely of elongated secretory cells, with an underlying submucosa and prominent circular and longitudinal muscle layers. The anterior part of the stomach contains a mucous surface epithelium and a network of tubular glands having only one type of glandular cell, to which secretion of both pepsinogen and HCl is attributed. The tubular glands are not present in the pyloric region. The gastric wall contains well developed circular muscle and submucosal layers. The pyloric caeca contain a mucosa containing two types of exocrine cells. The nature and function of secretions from these cells is discussed. The intestinal mucosa is differentiated into an anterior (ca. 30%) and a posterior section. The enterocytes of the anterior portion show evidence of lipid absorption, while those of the posterior intestine and rectum show considerable pinocytotic activity. The pyloric caeca, intestine, and rectum have a layer of submucosa and a thin layer of circular muscle. The presence of the prominent circular muscle in both the esophagus and the stomach is postulated to be advantageous to an herbivorous fish. However, other ultrastructural features of the gastrointestinal tract of the luderick are similar to those described in carnivorous fish and appear to show no specialization for herbivory.
Structure, function and evolution of the reproductive system in females ofHebrus pusillusandH. ruficeps(hemiptera, gerromorpha, hebridae)
Authors: Heming‐van Battum Karin E. , Heming B. S. 
Published: February 2005

AbstractFemales ofHebrus pusillusandH. ruficepshave two ovaries of five telotrophic ovarioles each, two lateral oviducts, a common an intricate sperm storage and delivery system, the gynatrial complex, and a short, tubular ovipositor. The skeletomusculature of this system is fully described in both species and its functions (summarized in Figs. 55–66) reconstructed from study of living bugs, dissections, whole mounts and serial sections.To mate, a maleH. pusillusjumps on the back of a female, induces her to lower her ovipositor, and, within 12 min (at 18–24°C), introduces the endosoma of his phallus up its shaft and fills his seminal duct with sperm. The female draws this into her gynatrial sac at the end of copulation and transfers it into her spermatheca in about 30 min (both sperm and spermatheca are longer than the female's body). A single, large egg passes from an ovariole into the vagina where its apex is temporarily lodged in a fertilization chamber. Spermatozoa are drawn from or swim out of the spermatheca into a grooved fecundation canal in the roof of the vagina and forward to the micropyle of the egg. After fertilization, the egg enters the base of the ovipositor and is deposited.The gynatrial complex of female, semiaquatic bugs probably evolved to accommodate the fertilization of the proportionately larger eggs of a lineage of bugs ancestral to Gerromorpha that was being selected for small body size and was then modified to increase the role of the female in controlling fertilization of eggs.
Structure of the brain and eye heater tissue in marlins, sailfish, and spearfishes
Authors: Block Barbara A. 
Published: February 2005

AbstractMarlins, sailfish, and spearfishes have a heat‐producing tissue beneath the brain and adjacent to the eyes. This tissue warms the brain and eyes while the rest of the body remains at water temperature. The heater tissue is derived from the superior rectus eye muscle. Only a portion of this eye muscle contains normal skeletal muscle tissue; the rest consists of the modified muscle tissue that is associated with heat production. The heat‐producing portion is supplied with blood through a countercurrent heat exchanger that originates from the carotid artery. The vascular rete prevents the heat being produced by the tissue from being dissipated at the gill. An unusual circulatory supply to the eyes and brain is associated with the presence of the heater tissue in these fishes.
Structural and functional relations of the white sturgeon alimentary canal (Acipenser transmontanus)
Authors: Buddington Randal K. , Doroshov Serge I. 
Published: February 2005

AbstractThe anatomy and histology of the white sturgeon digestive system is described for the adult stage and the first 36 days of posthatch development. Although the adult gut is only 87% of standard length, absorptive surface area is effectively increased by the thick mucosa of the postgastric gut and by lengthening of the gut due to the presence of the spiral valve and the pyloric caecum. Modifications of the gut of this species, relative to that of other chondrosteans, are consistent with its durophagous feeding habits. The arrangement of the intestinal epithelium differs from that of most fish and is organized so that absorptive activities occur in deeper regions, whereas goblet cells dominate the lumenally exposed epithelium. The gut develops from an intraembryonic yolk endoderm. At conclusion of the endogenous nutrition phase the alimentary canal is similar to the adult form and a functional gastric region is present. The anatomical characteristics coincide with physiological data collected throughout the life history of this species.
Transport of sperm within the cloaca of the female red‐spotted newt
Authors: Hardy Matthew P. , Dent James Norman 
Published: February 2005

AbstractThe transport of sperm in the cloaca and adjacent regions of the female red‐spotted newt was examined. It was found that within 1 min after sperm were introduced into the vent, they progressed in a random pattern past the apertures of the spermatheca (the gladular, sperm storage organ that opens from the anterior roof of the cloaca) forward to the anterior end of the cloaca and on into the posterior regions of the hindgut and bladder. Sperm did not enter the dorsal recess of the cloaca into which the oviducts and ureters open. After 1 day, few sperm remained within the cloaca lumen. Sperm were not transported into the cloacae of artifically inseminated, anesthetized females without prior administration of norepinephrine to their cloacal mounds. Treatment of the cloacal mounds of naturally inseminated females with an antagonist of neuromuscular transmission (lidocaine) decreased the numbers of sperm in the anterior cloaca relative to those of saline‐injected control specimens. Neither dead newt sperm nor live rabbit sperm entered the spermatheca. Rabbit sperm, however, entered the oviduct. It is argued that passive and active mechanisms of sperm transport work in concert. Contractions of smooth muscle, which may be initiated during courtship, probably serve to draw sperm passively into the cloaca and up to and beyond the apertures of spermathecal tubules, but sperm, once in the vicinity of those apertures, probably swim actively into them.
Structural and histochemical aspects of perirenal adipose tissue in fetal pigs: Relationships between stromal‐vascular characteristics and fat cell concentration and enzyme activity
Authors: Hausman G. J. , Thomas G. B. 
Published: February 2005

AbstractSamples of perirenal adipose tissue were obtained from four fetuses from each of seven crossbred gilts at each of three stages of gestation: 70, 90, and 110 days. Samples were routinely prepared for histochemistry and histology. At each age, the largest fat cell clusters were consistently located near points where large blood vessels entered the loose connective tissue. Cell‐cluster size decreased with distance from the entry points of large blood vessels. Fat cells proximal to entry points of large arterioles and fat cells distal to entry points of large arterioles were the same size. Enzyme cytochemistry disclosed that reactions for glucose‐6‐phosphate dehydrogenose (G6PDH), lipoprotein lipase (LPL) and NADH‐TR enzymes were reduced in distal (relative to entry points of large arterioles) adipocytes compared with proximal adipocytes. Reactions for succinate dehydrogenase (SDH) and lactate dehydrogenase (LDH) in adipocytes were not influenced by location within the tissue. Small fat cell clusters with sparse capillary beds surround arterioles in distal areas of sections from fetuses at 70, 90, and 110 days of gestation. In the proximal areas of sections from 110‐day‐old fetuses, arterioles were surrounded by large fat cell clusters with dense capillary beds. These characteristics serve to distinguish perirenal depots from subcutaneous depots in the fetus.
Comparative study of a new ultrastructural specialization of the mammalian retinal pigment epithelium: Basal intracytoplasmic tubules
Authors: Korte Gary E. , Goldberg Gary 
Published: February 2005

AbstractWe recently described basal intracytoplasmic tubules that arise from the basal plasma membrane of rat retinal pigment epithelial cells (RPE). They are a previously undescribed ultrastructural specialization of the basal plasma membrane in addition to the well‐known basal folds. This report describes similar tubules in the RPE cells of the rabbit, hamster, and kitten. As in the rat, the tubules in the hamster and kitten ramify singly through the basal cytoplasm and bear no special relationship to any other organelle. In the rabbit, however, stacks of closely apposed tubules frequently abut the large lipid droplets in their RPE cells. Although the function of the tubules is unknown, their occurrence in several different mammals suggests they are involved in the function of RPE cells in general.
Epididymis of the Indian wall lizard (Hemidactylus flaviviridis) during the sexual cycle and in response to mammalian pituitary gonadotropins and testosterone
Authors: Haider Shamim , Rai Umesh 
Published: February 2005

AbstractThe histology and histochemistry of the epididymis of the Indian wall lizard Hemidactylus flaviviridis (Rüppell) was studied in normal and hormone‐treated males. The ductus epididymidis showed a considerable variation in epithelial cell height and lumenal diameter along its length. It can be divided approximately into anterior, middle, and posterior regions. Epithelial cell height was maximal in the middle region and minimal in the posterior region. The lumen of the ductus epididymidis increased markedly in diameter from anterior to posterior ends with a concomitant increase in the sperm density. During the breeding phase, epithelial cell height and lumenal diameter of both ductuli and ductus epididymidis become markedly enlarged. The epithelium of reproductively active ducts was filled with secretory granules. Both the secretory granules of the epithelium and the secretory material mixed with sperm in the lumen showed a positive reaction to Sudan Black‐B, indicating the presence of lipid. The relative effects of mammalian FSH and LH on the regressed epididymis revealed that only FSH was capable of stimulating the growth and secretory activity of the epididymis.
Intrafusal muscle fibers of duck muscle spindles
Authors: Adal M. N. , Cheng S. B. Chew 
Published: February 2005

AbstractSerial transverse paraffin sections of intrafusal muscle fibers of spindles from the extensor pollicis and the extensor digitorum communis of ducks show that only one type of intrafusal muscle fiber exists, based on the mid‐equatorial nucleation pattern, diameter, and length. Although the overall range in fiber diameter at the mid‐equatorial region is between 4.2–20.0 μm, the average caliber is 10.4 ± 3.18 μm (S.D.) for spindles of the extensor pollicis and 9.3 ± 2.11 μm (S.D.) for spindles of the extensor digitorum communis muscles. The range in spindle length for the extensor pollicis is 290–2,090 μm, average 1,120 ± 569 μm (S.D.), and for the extensor digitorum communis 1,160–2,500 μm, average 1,745 ± 367 μm (S.D.). Therange in number of fibers per spindle for the extensor pollicis muscle is 5–12, average 8.2, and for the extensor digitorum muscle it is 1–11. In the extensor digitorum communis, there appear to be two groups, based on fiber number. Spindles of one group have a range of 5–11 fibers per spindle with an average of 7.2, whereas the second group has a range of 1–4 with an average of 2.7 fibers per spindle. The second group of spindles constitutes 52.5% of the 40 spindles studied, and of these 7.5% were monofibril spindles, 15.0% difibril, 17.5% trifibril, 12.5% quadrifibril spindles.
Cellular dynamics of conjugation in the ciliate euplotes aediculatus. II. Cellular membranes
Authors: Geyer James J. , Kloetzel John A. 
Published: February 2005

AbstractThe formation and subsequent dissolution of a common bridge of cytoplasm between conjugating ciliated protozoan cells provides an excellent opportunity to follow the dynamics of the cellular membrane systems involved in this process. In particular, separation of conjugant partners offers the chance to observe, at a fixed site on the cell surface, how the ciliate surface complex of plasma and alveolar membranes (collectively termed the “pellicle”) is constructed. Consequently, cortical and cellular membranes of Euplotes aediculatus were studied by light and electron microscopy through the conjugation sequence. A conjugant fusion zone of shared cytoplasm elaborates between the partner cells within their respective oral fields (peristomes) to include microtubules, cytosol, and a concentrated endoplasmic reticulum (heavily stained by osmium impregnation techniques) that may also be continuous with cortical ER of each cell. Cortical membranes displacd by fusion are autolyzed in acid phosphatase‐positive lysosomes in the fusion zone. As conjugants separate, expansion of the plasma membrane may occur through the fusion of vesicles with the plasma membrane, presumably at bare membrane, presumably at bare membrane patches near the fusion zone. The underlying cortical alveolar membranes and their plate‐like contents are reconstructed beneath the plasma membrane, apparently by multiple fusions of dense‐cored alveolar precursor vesicles (APVs). These precursor vesicles themselves appear to condense directly from the smooth ER present in the fusion zone. No Golgi apparatus was visible in the fusion zone cytoplasm, and no step of APV maturation that might involve the Golgi complex was noted.
Structure of hematopoietic nodules in the ridgeback prawn, Sicyonia ingentis: Light and electron microscopic observations
Authors: Martin Gary G. , Hose Jo Ellen , Kim Janet Jieun 
Published: February 2005

AbstractThe architecture and fine structure of the epigastric hematopoietic nodules of the ridgeback prawn, Sicyonia ingentis, are described. The nodules consist of a highly branched series of tubules that contain the maturing hemocytes within a connective tissue stroma. Hemocytes can exit the hematopoietic nodules by penetrating through fenestrations in the endothelial cell layer into the central hemal space or by migrating through the outer later of capsular cells and associated collagen fibrils. Four hemocyte categories were observed: agranular, small granule with cytoplasmic deposits, small granule without cytoplasmic deposits, and large granule hemocytes. This classification was based upon the presence, size, and type of cytoplasmic granules and the presence of cytoplasmic deposits. Only agranular cells and small granule hemocytes without cytoplasmic deposits appeared capable of division. Intermediate stages were observed between agranular hemocytes and small granule hemocytes with deposits and between small granule hemocytes without deposits and large granule hemocytes, suggesting existence of two distinct hemocyte lines.
Collateral projections from trigeminal sensory nuclei to ventrobasal thalamus and cerebellar cortex in rats
Authors: Patrick George W. , Robinson Merryn A. 
Published: February 2005

AbstractThe retrograde fluorescent labeling technique reveals that trigeminal projections to the ventroposteromedial nucleus of the thalamus (VPM) of the rat originate from the main sensory nucleus (MSN) of the trigeminal and subnuclei interpolaris (V1) and caudalis (Vc) of the spinal trigeminal nucleus. These projections are predominately contralateral; however, the presence of a few ipsilateral labeled cells in MSN suggests an uncrossed trigeminothalamic pathway. Trigeminocerebellar fibers projecting to the paramedian lobule (PML) of the cerebellar cortex are located in Vi and caudal subnucleus oralis (V0). This is principally an ipsilateral pathway, but several bisbenzimide‐labeled cells are present in contralateral Vi. The most notable finding occurred after paired injections of Evans Blue into VPM and bisbenzimide into PML, demonstrating neurons in Vi with divergent projections to both structures. The presence of this type of projection was not found in mice (Steindler: J. Comp. Neurol. 237:155–175, 1985) and has not been reported in other species.
Oogenesls in the terrestrial hermit crab, coenobita clypeatus (decapoda, anomura): II. Vitellogenesis
Authors: Komm Barry S. , Hinsch Gertrude W. 
Published: February 2005

AbstractOocytes from the land hermit crab, Coenobita clypeatus, in various stages of vitellogenesis were examined by light and electron microscopy. Early vitellogenic oocytes are characterized by accumulations of discrete vesicles of endoplasmic reticulum in the perinuclear cytoplasm. As oocytes develop, the endoplasmic reticulum becomes abundant, and numerous Golgi complexes are seen. There is a well developed Golgi‐endoplasmic reticulum interaction. Within the confines of the reticulum are discrete intracisternal granules, which can be seen coalescing into electron‐dense yolk bodies. Lipid accumulation is seen throughout the cytoplasm. Coincident with the burst of intra‐oocytic metabolism are oolemma modifications and micropinocytosis, which provide ultrastructural evidence for extra‐oocytic yolk production. The mature oocyte contains numerous yolk and lipid vesicles of varying electron density that comprise both intra‐ and extra‐oocytic substrates.
Fine structure and absorption of ferritin in the digestive organs of Loligo vulgaris and L. Forbesi (Cephalopoda, Teuthoidea)
Authors: Boucher‐Rodoni Renata , Boucaud‐Camou Eve 
Published: February 2005

AbstractThe digestive organs possibly involved in food absorption in Loligo vulgaris and L. forbesi are the caecum, the intestine, the digestive gland, and the digestive duct appendages. The histology and the fine structure showed that the ciliated organ, the caecal sac, and the intestine are lined with a ciliated epithelium. The ciliary rootlets are particularly well developed in the ciliated organ, apparently in relation to its function of particle collection. Mucous cells are present in the ciliated organ and the intestine. Histologically, the digestive gland appears rather different from that of other cephalopods. However, the fine structure of individual types of squid digestive cell is actually similar to that of comparable organs in other species, and the squid cells undergo the same stages of activity. Digestive cells have a brush border of microvilli, and numerous vacuoles, which sometimes contain “brown bodies.” However, no “boules” (conspicuous protein inclusions of digestive cells in other species) could be identified in their cytoplasm; instead only secretory granules are present. In the digestive duct appendages, numerous membrane infoldings associated with mitochondria are characteristic features of the epithelial cells in all cephalopods. Two unusual features were observed in Loligo: first, the large size of the lipid inclusions in the digestive gland, in the caecal sac, and in the digestive duct appendages; and second, the large number of conspicuous mitochondria with well‐developed tubular cristae. When injected into the caecal sac, ferritin molecules can reach the digestive gland and the digestive duct appendages via the digestive ducts, and they are taken up by endocytosis in the digestive cells. Thus, it appears that the digestive gland of Loligo can act as an absorptive organ as it does in other cephalopods.
Seasonal changes in a lizard pituitary: Immunocytochemistry and ultrastructural morphometry of lactotropes, corticotropes, and gonadotropes
Authors: Pearson Anita K. , Licht Paul 
Published: February 2005

AbstractPituitary glands of adult male lizards (Anolis carolinensis) were studied in an effort to monitor seasonal cytologic changes quantitatively. Cells were identified immunocytochemically and on the basis of ultrastructural characteristics.Electron micrographs of the anterior pars distalis (containing lactotropes, corticotropes, and gonadotropes) of lizards collected in spring and fall were analyzed morphometrically. Lactotropes are the most numerous cell type in this area and occupy the largest volume. They are closely followed by corticotropes. Neither kind of cell undergoes a marked seasonal change in number or size or in the percent of the analyzed volume they occupy. Morphometric and ultrastructural criteria indicate an increased level of activity in all three kinds of secretory cells in the spring, although changes are relatively modest in corticotropes and lactotropes.Gonadotropes occupy less than half the volume of either of the other secretory cells in the analyzed area, but undergo considerable seasonal modification. They are larger (> 40%) and more numerous (20%) in the spring, and show an increase in biosynthetic organelles at this time. Although the density of secretion granules may be reduced in the enlarged spring gonadotropes, the number of granules per cell may not be altered seasonally.Seasonal changes in the three cell types analyzed are moderate in contrast to the cytologic modifications described in pituitary cells following castration or other experimental procedures. Necrotic cells appear to be a normal component of the pituitary gland of Anolis carolinensis throughout the year.