bluuebunny/crossref_metadata_2025_split huggingface dataset:
Histophysiology of a primary immune response against Aeromonas hydrophila in carp (Cyprinus carpio L.)
Authors: Lamers Cor H. J. 
Published: June 2005

AbstractHistological and immunological parameters were monitored in carp during the primary immune response against Aeromonas hydrophila. Localization of antigen in the spleen initially ocurred in the ellipsoids, whereas in the head and trunk kidney it was diffusely distributed. When antibody titers increased (from day 9 onwards), antigen accumulated in melano‐macrophage clusters in all three organs, and it was mainly bound to cell membranes. Tissue‐bound immunoglobulin was present on several structures in the lymphoid organs. As a consequence of immunization, the number of cells with cytoplasmic immunoglobulin and the amount of immunoglobulin associated with the reticular sheath of ellipsoids and membranes of melano‐macrophages increased. Pyroninophilia was limited, and occurred in the spleen associated with ellipsoids; in addition, clusters of cells appeared, displaying a small rim of pyroninophilic cytoplasm. In the kidney the reaction was not conspicuous. The number of antibody forming cells in the head kidney peaked at day 9 and the serum antibody response followed with a peak at day 15. When the antigen was emulsified in adjuvant, the antigen processing and the antibody responses were affected. Antigen processing was retarded and a second burst of antibody production occurred from day 15 onwards. The relationship of melano‐macrophage centers with immunological processes is considered. It is suggested that in fish these centers might be primitive analogues of the mammalian germinal centers.
Descriptive kinetics of spermatogenesis in four chromosomal species of the Spalax ehrenbergi superspecies in Israel
Authors: Redi C. A. , Garagna S. , Heth G. , Nevo E. 
Published: June 2005

AbstractThe descriptive kinetics of the spermatogenic process has been studied in the four chromosomal species of Spalax ehrenbergi between November and March, the active period of reproduction.Spermatid development can be subdivided into 16 steps in which the acrosome formation is clearly distinguishable and the Golgi, cap and acrosomic phases are identifiable. The first 12 steps of spermiogenesis can be utilized for the definition of characteristic time‐dependent relationships among different germ cell associations (stages): twelve stages, I–XII, are clearly identifiable.In this regard no differences exist among the four chromosomal species. In general, the spermatogenic process in this species has the same pattern as that of Mus domesticus. Two relevant points distinguish Spalax spermatogenesis from Mus spermatogenesis: 1) the presence, throughout the stages I–XII of the seminiferous epithelium cycle of a larger size, oval shaped spermatogonium type containing heterochromatic granulations; 2) the Sertoli cells show only one heterochromatic clump closely attached to the nucleolus; moreover, the Sertoli cell cytoplasm is more PAS‐positive than that of Mus.
Inhibition of fertilization of the rabbit ova in vitro by the antibody to the inner acrosomal membrane of rabbit spermatozoa
Authors: Srivastava P. N. , Sheikhnejad Reza G. , Fayrer‐Hosken R. , Malter H. , Brackett B. G. 
Published: June 2005

AbstractThe antibody to the rabbit sperm inner acrosomal membrane, raised in guinea pig, completely inhibited the fertilization of rabbit ova in vitro. The F(ab′)2 of the antibody was equally effective in inhibiting fertilization. The antibody appeared to exert its inhibitory effect by binding to the inner acrosomal membrane of acrosome‐reacted sperm. The antibody‐treated sperm did not attach to or penetrate the zona pellucida. Thus, anti‐IAM offers a great potential as a contraceptive agent.
The histochemical identification of primordial germ cells in diploid parthenogenetic mouse embryos
Authors: Kaufman M. H. , Schnebelen M. T. 
Published: June 2005

AbstractAn attempt has been made to improve the early post‐implantation development potential of diploid parthenogenetic mouse embryos by transferring parthenogenetic blastocysts to one uterine horn of a pseudopregnant recipient and a similar number of fertilized embryos to the contralateral horn. In control studies, diploid parthenogenetic embryos were transferred to both uterine horns of appropriate recipients. Unfortunately no obvious advantage appeared to be gained by carrying out the former manoeuvre. A significant improvement in the development potential of the parthenogenones could have indicated that their poor post‐implantation survival might have been associated with a deficiency, possibly of hormonal origin, in the functioning of their decidual reaction. However, sufficient somite‐containing parthenogenetic embryos were obtained in this study to allow a comparison to be made between them and fertilized embryos that were morphologically at a comparable stage of development. The parthenogenones were found to have a markedly smaller crown–rump length than their fertilized counterparts. A high proportion of both the parthenogenetic and fertilized embryos were subsequently fixed and appropriately stained in order to localize alkaline phosphatase activity. The analysis of this material clearly demonstrated that parthenogenetic mouse embryos are in fact capable of producing primordial germ cells. The latter were recognized by their morphology, histochemical staining appearance, and characteristic location, being found in the early ‘turned’ embryos within the dorsal mesentery in close proximity to the developing gut tube, and in the more advanced limb‐bud stage embryos within the gonadal ridges.
Relationship between calcium binding sites and membrane fusion during the acrosome reaction induced by lonophore in ram spermatozoa
Authors: Watson P. F. , Plummer J. M. 
Published: June 2005

AbstractRam spermatozoa treated with the ionophore A23187, to induce the acrosome reaction, were fixed in pyroantimonate‐osmium in order to demonstrate calcium at an ultrastructural level. Prior to vesiculation, granules of precipitate occurred at points of contact between plasma and outer acrosomal membranes, suggesting a discrete role for calcium during membrane fusion. The earliest stages of vesiculation always occurred in the region just anterior to the equatorial segment and it was this same site where a marked concentration of precipitate, indicating calcium binding sites, could be demonstrated.
Secretion of prolactin‐synergizing activity (synlactin) by the liver of ectothermic vertebrates in vitro
Authors: Delidow Beverly C. , Hebert Nora , Steiny Susan , Nicoll Charles S. 
Published: June 2005

AbstractRecent work in our laboratory indicated that the liver of rats and pigeons secretes a prolactin synergist (synlactin) in vitro. We have investigated the secretion of this activity by the liver of nine species of ectothermic vertebrates. Liver from three teleosts (goby, salmon, and tilapia), four amphibians (Ambystoma, Necturus, bullfrog, and grass frog) and two reptiles (turtle and anole) was diced, washed, and incubated for 3 hr in isotonic medium. After dialysis, the liver incubation media (LIM) were tested with and without prolactin (PRL) in the local pigeon crop‐sac bioassay. The LIM for turtle, larval bullfrog, freshwater salmon, and 5% seawater‐adapted goby significantly augmented the local crop‐sac response to PRL, but the LIM from anole, adult bullfrog, grass frog, fasted larval Ambystoma, Necturus, 100% seawater‐adapted goby, and tilapia did not contain synergizing activity. We conclude that synlactin is secreted by the liver of several species representing three of the major ectothermic classes of vertebrates. It is significant that in two cases, larval bullfrog and 5% seawater‐adapted goby, the presence of synlactin occurs in physiological states in which PRL is active. In the opposite cases (adult frog and 100% seawater‐adapted goby) the activity was not detectable. We also found that the liver of larval and adult bullfrogs and tilapia released a factor in vitro that had proliferative activity in the crop‐sac. This activity appears to be distinct from synlactin.
Effects of the lethal yellow (Ay) and recessive yellow (e) genes on the population of epidermal melanocytes in newborn mice
Authors: Tamate Hidetoshi B. , Hirobe Tomohisa , Takeuchi Takuji 
Published: June 2005

AbstractVery few melanocytes can be detected by the DOPA reaction in the dorsal epidermis of newborn lethal yellow mice (Ay/a). Nevertheless, the epidermis contains a considerable number of melanoblasts (cells positive for the combined DOPA‐premelanin reaction). On the other hand, numerous melanocytes as well as melanoblasts are found in the dorsal epidermis of black mice (a/a). The number of epidermal melanoblasts is smaller in (Ay/a than in a/a mice even though the same number of melanocytes is found in the dermis of these animals. It seems probable that the product of the Ay gene suppresses either the differentiation or the proliferation of epidermal melanoblasts.The number of melanoblasts plus melanocytes in day‐17 embryos from a cross between Ay/a and a/a mice shows a bimodal distribution. It seems possible that half of the embryos were Ay/a and possessed a reduced number of melanoblasts and melanocytes. This result seems to suggest that the Ay gene is active at this embryonic stage.In contrast to the case for the epidermis from Ay/a mice, numerous DOPA‐positive melanocytes were detected in the epidermis from e/e mice. However, the total number of melanoblasts plus melanocytes in e/e epidermis did not differ from that in Ay/a epidermis, suggesting that the mode of action of the e gene in the epidermis is different from that of the Ay gene.
Presence of a substance crossreacting with cortical alveolar material in “yolk vesicles” of growing oocytes of Oryzias latipes
Authors: Masuda Kaori , Iuchi Ichiro , Iwamori Masao , Nagai Yoshitaka , Yamagami Kenjiro 
Published: June 2005

AbstractA large number of spherical bodies, a major insoluble component of cortical alveolus, were isolated from blastulae of medaka, Oryzias latipes. Spherical body material was found to be abundant in carbohydrates, especially in galactose and hexosamine, and total carbohydrate content amounted to about 1.3 times that of protein. Immunohistochemical studies using anti‐spherical body antiserum as a probe revealed that a substance crossreacting with spherical body material was localized only in “yolk vesicles” of growing oocytes and later in cortical alveoli of full‐grown oocytes. Thus the present results identified immunochemically yolk vesicle material with cortical alveolar material, supporting the view that the yolk vesicle is a precursory structure of cortical alveolus.
Metamorphosis of the American eel, Anguilla rostrata Le Seur: II. Structural reorganisation of the locomotory musculature
Authors: Egginton Stuart 
Published: June 2005

AbstractSkeletal muscle types show a differential response in both organization and morphology on transition from non‐migratory (yellow eel) to migratory (silver eel) life‐history stages. Volume density, Vv, and surface density, Sv, of intracellular components and the capillary network reflect structural limits to aerobic metabolism, and parallel changes seen in metabolic potential using enzyme activity measurements. Increased capacity for aerobic ATP supply is apparently derived from an increase in mitochondrial Vv from 16% to 22% of slow fiber volume in silver eels. Cristae Sv appears not to vary with the level of aerobic metabolism: Sv (cst, mit) is 46.8 and 44.0 μ2 · μm−3 in slow muscle fibers of yellow and silver eel, respectively, and 38–43 μ2 · μm−3 in fast fibers. The large amount of intracellular lipid in slow fibers of silver eel, around 25% of fiber volume, contrasts with only 4% in fibers of yellow eel. This is consistent with the contention that mature, migratory fish rely heavily on lipid metabolism.Maturation appears to induce only minor changes in fast muscle morphology, reflecting a potentially constant work capacity and suggesting that the slow muscle system supports the increased energy demand for extensive locomotion. Change in relative proportion of slow muscle, from 8.6% to 14.4% of total muscle mass, is largely due to cellular hypertrophy. This amplifies the cellular reorganization, increasing total mitochondrial volume of slow muscle from 0.7% to 1.6 cm3 for 100g yellow and silver eels, respectively. Changes in skeletal muscle during transition from yellow to silver life‐history stages are therefore both qualitative and quantitative, and represent a true metamorphosis.
Local light stimulation of melanophores of a teleost, Zacco temmincki
Authors: Iga Tetsuro , Takabatake Ikuo 
Published: June 2005

AbstractResponses of melanophores of the teleost, Zacco temmincki, to local light stimulation were examined in preparations of isolated scales. The melanophores induced the aggregation of melanosomes in darkness and their dispersion in light. Local illumination of a melanophore in the melanosome‐dispersed state inhibited centripetal migration of melanosomes only in the stimulated area. Local illumination of a pigment‐free branch of a melanophore with aggregated melanosomes generally brought about pigment dispersion into the stimulated area. However, when that area was at a significant distance from the edge of the central melanosome mass, the melanosomes never migrated into the irradiated area. Local illumination of the centrosphere of a cell inhibited the full aggregation of melanosomes in the dispersed and aggregated state. The degree of the inhibition depended on the size of the irradiated area. The result suggest that photoreceptive sites are distributed over the whole of a cell, and that the movements of melanosomes are regulated locally in a very precise manner.
Avian hepatic T‐3 production by two pathways of 5′‐monodeiodination: Effects of fasting and patterns during development
Authors: Hughes Thomas E. , McNabb F. M. Anne 
Published: June 2005

AbstractTwo forms of iodothyronine 5′‐monodeidinase (5′‐D) were studied in liver homogenates from adult and developing quail. The influence of fasting in adults and corticosterone treatment in embryonic quail on 5′‐D also were examined. Liver homogenates were assayed for 5′‐D activity in the presence of abundant substrate (T4) and cofactor (dithiothreitol; DTT). Generation of T3 during a 15 min incubation at 37°C was assessed by an ethanolbased RIA. In adults, both Type I [the fraction of activity inhibited by propylthiouracil (PTU)] and a putative Type II (the PTU‐insensitive fraction) were present in liver homogenates. Type II activity typically comprised about 30% of Total activity.Type I activity first appeared on day 15 of the 16.5 day incubation period, increased 20‐fold to peak at hatching, then gradully declined to reach adult levels by 21 days of age. Type II activity was present at all developmental stages and was highest during the perinatal period. Corticosterone treatment in vivo on day 13 of development induced increases in both Type I and Type II activities in liver homogenates 24‐ and 48‐h after treatment.This study demonstrates that in avian liver a putative Type II 5′‐D activity (generally considered to be lacking in mammalian‐liver) is present and may be important in the maintenance of minimal concentrations of tissue T3 during fasting. Both types of 5′‐D contribute to the developmental pattern of serum T3 concentrations. Type II comprises a large proportion of total activity during late embryonic life; Type I becomes predominant at the beginning of the perinatal period. Corticosterone is capable of inducing increases in both Type I and Type II activities during late embryonic life.
Cytoplasmic control of chromosome diminution in Ascaris suum
Authors: Oliver Brian C. , Shen Sheldon S. 
Published: June 2005

AbstractThe elimination of portions of chromosomes (chromosome diminution) in Ascaris sp. is an early event associated with divisions of somatic blastomeres. Germ‐line blastomeres do not undergo diminution during cell division. It has been proposed that the occurrence of chromosome diminution is under the control of morphogenetic determinant(s) in the ooplasm, which are fixed into specific blastomeres by the cleavage process. The nature of the morphogenetic determinant(s) contained in the cytoplasm remains an enigma. Two problems with the Ascaris sp. system have been an impermeable extra embryonic (ascaroside) layer and the difficulty of scoring interphase nuclei as somatic (diminished) or germ‐line (non‐diminished). We have successfully permeabilized the ascaroside layer by puncture with micropipettes. We also report a Ba(OH)2 C‐banding technique, which preferentially stains germ‐line limited chromatin in anaphase, telophase, and interphase nuclei. These two techniques have allowed us to (1) produce early embryos with multinucleated blastomeres (coenocytic embryos) of Ascaris suum and (2) assay for the effects on chromosome diminution brought about by these altered cytoplasmic environments. The patterns of diminution seen in one‐cell and two‐cell coenocytic embryos strongly suggest the presence of cytoplasmic determinats. Since chromosome diminution serves as a marker of blastomere commitment, these determinants may also play a role in the commitment of blastomeres to the germ‐line.
Genetic variation in Drosophila melanogaster for the life‐shortening effects of random lighting regimes
Authors: Ringo John M. , Dowse Harold B. , Lagasse Steven , Ezzy Stephen 
Published: June 2005

AbstractA daily random light‐dark regime (RLD), in which the onset of the photophase occurred at a random time of the 24‐h day, significantly shortened the life span of adult Drosophila melanogaster in 8 out of 23 strains tested. For the eight sensitive strains, the mean percent decrement in LT50 ± SE was 11.2 ± 0.6 d; for ten resistant strains, the mean decrement was 5.1 ± 0.8 d; for the remaining 5 strains, which could not be unambiguously classified as sensitive to RLD, the mean decrement was 8.6 ± 1.1 d. Strains homozygous for whole chromosomes (either X or one of the two large autosomes) exhibited continuous variation for sensitivity to clock shifting. No chromosome accounted for a disproportionate share of the variation, suggesting a multigenic basis for this phenotype. The LT50 in a normal, constant light‐dark regime (CLD) ranged from 31.7 d to 65.3 d, with chromosome 2 contributing most heavily to this variation. The correlation between LT50 and percent decrement in LT50 was not significant (r = .23, df = 21, P > .20). In most sensitive strains, RLD and CLD groups did not begin to differ in percent surviving until after .5 of CLD LT50; after this critical point, RLD animals started dying at an increased rate. RLD may be stressful by disrupting temporal organization of physiological processes immediately following phase shifts, during the period marked by transients in observed phase response.
Actin filament bundle in the acrosome of abalone spermatoza
Authors: Shiroya Yoko , Hosoya Hiroshi , Mabuchi Issei , Sakai Yoshi T. 
Published: June 2005

AbstractThe localization of actin filaments in abalone sperm was investigated using 7‐nitrobenz‐2‐oxa‐1,3,‐diazole‐phallacidin (NBD‐phallacidin) as a specific probe for actin filaments. Fluorescence staining of intact sperm revealed the localization of actin filaments in the axial rod. After the acrosome reaction the fluorescent rod elongated to form the acrosomal process, which signified the elongation of actin filaments. More definite identification of the bundle of filaments in the axial rod as filamentous actin was indicated by decoration with myosin subfragment 1 (S1). The actin filaments in both the unreacted and reacted sperm all appeared decorated with S1, and the polarity was found to be unidirectional with the arrowheads pointing towards the nucleus. When Triton X‐100‐treated unreacted sperm were incubated in exogenous G‐actin, actin monomers assembled on the “barbed end” of the actin filaments of the axial rod. These results suggest that the elongation of the acrosomal process occurs via polymerization of endogenous G‐actin at the tip (the barbed end) of the axial rod.
Responses to reversed NH3 and NH4+ gradients in a teleost (Ictalurus punctatus), an elasmobranch (Raja erinacea), and a crustacean (Callinectes sapidus): Evidence for NH4+/H+ exchange in the teleost and the elasmobranch
Authors: Cameron James N. 
Published: June 2005

AbstractAmmonia excretion rates of channel catfish, Ictalurus punctatus, little skate (Raja erinacea), and blue crab (Callinectes sapidus) were measured in experimental regimes which permitted simultaneous assessment of the partial pressure gradients for nonionized NH3 and the chemical concentration gradients of NH4+. Under conditions of low external ammonia, the average ammonia excretion was +295 μM kg−1 h−1 for catfish, + 149 μM kg−1 h−1 for blue crabs, and +59 μM kg−1h−1 for skates with partial pressure gradients of +72.5 μTorr, + 413 μTorr, and +24.4 μTorr, respectively; and [NH4+] gradients of +189 μM l−1, +643 μM l−1, and +107 μM l−1 (positive indicating greater from inside to medium). When the external ammonia was increased to 1.15 mM l−1, both gradients were reversed, and the net ammonia movement was initially from the external water into all three species. In the catfish the inward movement ceased, however, and ammonia excretion eventually resumed in the face of reversed gradients of both NH3 partial pressure and [NH4+]. Unidirectional Na+ influx, indicative of a Na+/NH4+ exchange, did not increase. The ammonia data, changes in titratable acidity, and net apparent H+ efflux were all consistent with a linked extrusion of internal NH4+ for external H+. Incorporation of such an exchange into a computer simulation model of the ammonia equilibrium and exchange system duplicated the experimental data. Other hypotheses failed to match experimental data, or failed to predict internal ammonia levels lower than outside. In the crab, internal ammonia levels rose rapidly to concentrations and partial pressures above the external medium until excretion was reestablished, with no evidence of maintenance of a reversed gradient. In the skate, internal concentrations rose appreciably in the first hour and continued to rise for 6–8 h, with no resumption of ammonia excretion. The interspecies differences appear to be due at least partly to differences in ammonia permeability of the gills.
Regenerate epithelium and skin glands of the adult newt react to the same monoclonal antibody
Authors: Tassava Roy A. , Johnson‐Wint Barbara , Gross Jerome 
Published: June 2005

AbstractA search for specific proteins involved in newt limb regeneration, using monoclonal antibodies against forelimb blastemas, led to the detection of an antigen in the regenerate epithelium. Fluorescent‐antibody‐labeled cells first appeared just prior to blastema outgrowth. From bud through early digit stages this antibody reacted with nearly all of the regenerate epithelial cells. Other tissues also reacted, including nerve, blood vessels, and gastrointestinal tract. The behavior of the reactive cells in the regenerate epithelium, and their close association with immediately adjacent skin glands, raises several new possibilities for the origin of the regenerate epithelium.