bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of colchicine‐ and cytochalasin B‐treatment on the intracellular distribution of yolk droplets, lipid bodies, and golgi apparatus of the chick neuroepithelial cells
Authors: Fernandez J. G. , Chamorro C. A. , de Paz P. , Villar J. M. 
Published: June 2005

AbstractTreatment with colchicine (antimicrotubular agent) and cytochalasin B (antimicrofil‐amentous agent) has been used to investigate the possible role played by the cytoskeleton in the maintenance of intracellular distribution of yolk droplets, lipid bodies, and Golgi apparatus of the chick neuroepithelial cells. On the one hand, embryos treated with colchicine showed modifications in their distribution patterns of yolk droplets and lipid bodies, which suggests the involvement of the microtubular integrity of neuroepithelial cells in the maintenance of normal distribution patterns. On the other hand, the close relationships between vitelline and lipid inclusions and Golgi apparatus observed in untreated embryos seems to be kept in the embryos treated with colchicine and cytochalasin B. Moreover, from the effects of colchicine on Golgi apparatus position a possible functional role for the microtubular system in the maintenance of Golgi apparatus polarity in the chick neuroepithelial cells can be proposed. The results provided here constitute new information about the cellular mechanisms involved in chick neurulation.
The amylase gene–enzyme system of fishes. I. Developmental expression of amylase in the mosquitofish
Authors: Yardley Darrell G. 
Published: June 2005

AbstractThe objective of this study is to examine the effects of developmental stage on amylase expression in the mosquitofish (Gambusia affinis holbrooki, Poeciliidae). Expression was characterized in terms of amylase activity and amount of amylase protein in five developmental stages: early, mid, and late embryos, 5‐day‐old juveniles, and adults. Two measures of activity were used: a starch‐iodine assay, which measures the change in substrate, and the dinitrosalicyclic acid (DNSA) assay, which measures the change in product. To measure changes in the amount of amylase, the enzyme‐linked immunosorbent assay (ELISA) was used. Highest activity and amount was observed in the adult stage. In general, both increased with development. While the two activity measures were positively correlated, these were only weakly correlated with the amount of amylase. Possible reasons for these weak correlations between amylase activity and amount are discussed.
Response of the interrenal to adrenocorticotropic hormone after short‐term thyroxine treatment of coho salmon (Oncorhynchus kisutch)
Authors: Young Graham , Lin Richard J. 
Published: June 2005

AbstractThe effects of experimentally elevated plasma thyroxine levels on the subsequent response of interrenals of coho salmon (Oncorhynchus kisutch) to adrenocorticotropic hormone (ACTH) in vitro were examined. Animals were treated with thyroxine by immersion (200 μg/L) for 3 days, which resulted in physiological elevations in circulating thyroxine. In animals treated before the parr‐smolt transformation was completed (early smolts), thyroxine had no effect on plasma cortisol levels but significantly enhanced the sensitivity of the interrenal to ACTH in vitro. In animals treated after the period of smoltification (postsmolts), plasma cortisol levels were significantly higher than those of controls; both experimental and control animals had plasma cortisol levels higher than normally observed at this stage of development. The response of the interrenals of thyroxine‐treated postsmolts to ACTH in vitro was significantly lower than that of controls. Results from the experiments using early smolts are in agreement with studies in other vertebrates showing that thyroid hormones are involved in maintaining the normal functioning of corticosteroidogenic tissue and suggest that thyroid hormones may be involved in the activation of the interrenal that occurs during smoltification. The results obtained using postsmolts are more difficult to interpret because of the possibility that these animals were physiologically stressed by the treatment. Increased ACTH release in vivo resulting from stress may have led to a depression of interrenal sensitivity to ACTH in vitro and may have masked a refractoriness of the pituitary‐interrenal axis to thyroxine.
Differential localization of glycoconjugates having affinity for concanavalin A on the surface of the sperm head in the testis, the epididymis, and the ejaculate of the ram
Authors: Delpech S. , Hamamah S. , Pisselet Cl. , Courot M. 
Published: June 2005

AbstractThe localization of Con A receptors on the surface of the head of ram spermatozoa originating from the rete testis, from three regions of the epididymis, or from the ejaculate was investigated using a gold‐Con A labelling technique. Electron microscopic observation revealed three major localizations, each being characteristic of the origin of the spermatozoa: periacrosomal in the rete testis, postacrosomal in the epididymis, on the entire surface of the sperm head in the ejaculate.
Chorionic peroxidase activity in the eggs of the fish Tribolodon hakonensis
Authors: Kudo Shigeharu , Sato Atsuhiko , Inoue Matsuhisa 
Published: June 2005

AbstractPeroxidase activity was ultracytochemically demonstrated in the vitelline and fertilization envelopes of eggs of the fish Tribolodon hakonensis. The vitelline envelope (VE) was morphologically divided into five layers, from the first to the fifth, numbered in order from the outside of the VE toward the interior, but the micropylar and surrounding region lacked the first layer. Peroxidase activity was localized in the first and second layers, but was much stronger in the latter than in the former. Phosphotungstic acid (PTA) staining was positive in the first layer alone. During the elevation of the fertilization envelope (FE) the peroxidase activity was translocated into the first layer of the FE from the second layer. This translocation resulted in much weaker activity or negativity in the FE second layer. In the micropylar and surrounding region, however, peroxidase activity remained unchanged, and there was no translocation. Transformation of the VE into the FE led to an alteration in the thickness of each layer and in the cytochemical nature of the first layer. There was almost no PTA staining in the FE first layer, except for a few scattered positive spots. A purified and lyophilized VEs‐ or FEs‐NaI‐H2O2 system exerted a cell‐killing effect on three bacterial species tested.
Bufo japonicus japonicus and Xenopus laevis laevis egg jellies contain structurally related antigens and cortical granule lectin ligands
Authors: Hedrick Jerry L. , Katagiri Chiaki 
Published: June 2005

AbstractThe antigenic relationship of the egg jelly coat glycoproteins from Bufo japonicus japonicus and Xenopus laevis laevis was investigated using agar double diffusion methods. The presence of ligands in the jelly coats for the cortical granule lectin from X. l. laevis eggs was also investigated. Anti‐jelly serum for both anuran species crossreacted with the jelly coat from the other species with precipitin patterns of identity. Each egg jelly coat of both species contained two ligands for the cortical granule lectin. Although the ligands in the two different jelly coats appeared to react with the lectin in a pattern of identity, the species ligands were antigenically distinguishable using anti‐Xenopus jelly serum. The observations that the two anuran egg jelly coats were antigenically related and that they both contained ligands for the X. l. laevis cortical granule lectin was interpreted in terms of fertilization mechanisms in the two different species. In addition, these observations bring into question the currently accepted phylogenetic relationship of B.j. japonicus and X.l. laevis.
Chloride transport and the electrophysiological properties of the isolated skin of the shanny (Blennius pholis L.)
Authors: Williams E. M. , Eddy F. B. , Ward M. R. 
Published: June 2005

AbstractThe isolated open‐circuited shanny skin exhibited a net chloride efflux of 2.91 μmol h−1. The transepithelial potential was 12 mV (inside + ve). Short circuit current was 60 μA cm2 and transepithelial resistance was 225 Ω cm2. When either ouabain or furosemide was added to the inside, or amiloride or 4‐acetamido‐4′‐isothiocyanatostibene‐2,2′‐disulphonic acid (SITS) was added to the outside, the transepithelial potential and short‐circuit current were reduced. The results are discussed and a model is presented that describes the possible mechanism for chloride transport across shanny skin.
Purine and pteridine pigments of light‐ and dark‐colored arizona tiger salamanders
Authors: Fernandez Philip J. 
Published: June 2005

AbstractPale yellow Arizona tiger salamander larvae (Ambystoma tigrinum nebulosum Hal‐lowell) were collected from a turbid pond, and dark green larvae were collected from a clear pond. Light‐colored larvae metamorphosed into salamanders with predominantly yellow skin, while dark‐colored larvae metamorphosed into black individuals with few yellow markings. Skin of light‐colored salamanders had abundant yellow xanthophores and silver‐reflecting iridophores. Skin of dark‐colored salamanders was covered with fully expanded melanophores. Concentration of yellow pteridine and blue‐green reflecting purine pigments, extracted from skin of light and dark‐colored salamanders, was compared fluorometrically and spectrophotometrically. There was no difference in total pteridine content between light and dark‐colored salamanders. However, the average concentration of the pteridine xanthopterin was greater in dark rather than light‐colored larvae. In addition there was four times more guanine in skin of light‐colored larvae than in dark‐colored larvae, which indicates salamanders increased iridophore deposits of guanine in the turbid pond.
Embryonic osmoregulation: Consequences of high and low water loss during incubation of the chicken egg
Authors: Davis Thomas A. , Shen Sheldon S. , Ackerman Ralph A. 
Published: June 2005

AbstractThe rates of water loss of domestic chicken eggs were varied during incubation to measure the osmoregulatory ability of the avian embryo. Egg water loss was increased by drilling holes in the eggshell over the airspace on day 13 (I = 21 days) and then placing these eggs in a low relative humidity (r.h.: 0–10%) incubator until hatch. Egg water loss was decreased by placing other eggs in a high‐r.h. (85–90%) incubator on day 0. Eggs with low water loss (∼ 6% of initial fresh mass [IFM]) produced embryos and yolks that were not different in wet or dry mass when compared to control eggs that lost ∼ 12% of IFM. However, 1–4 gm of excess albumen were left in low‐water‐loss eggs on day 21. Hatching success was 71% and 89% for low and control eggs, respectively. Low egg water loss did not appear to disturb embryonic growth. The allantoic fluid volume and millimolar allantoic Na+ and Cl− ions declined faster with high and slower with low rates of water loss. Thus, excess water was lost as a result of increased movement of water out of allantoic fluid, which was due to increased active transport of Na+ ions by the chorioallantoic membrane (CAM). Eggs with high water loss had elevated Cl− levels after day 17 in plasma and amniotic fluid, which indicated a period of osmotic stress after depletion of allantoic fluid between day 18 and hatch. The decrease in wet embryo mass measured in embryos from high‐water‐loss eggs was due principally to dehydration of skin. Embryonic skin may serve as an emergency water reservoir during osmotic stress. Dehydrated chicks produced from high‐water‐loss eggs were 6 gm less in wet mass at hatch compared to controls. However, these chicks regained the water deficit 7 days after hatch and grew at a rate not different from control chicks through 6 weeks of age. Total egg water loss of 12% of IFM results in highest hatching success. However, water losses between 6% and 20% of IFM do not appear to affect adversely the growth or water content of the chick. Water losses above 20% of IFM cause early depletion of allantoic fluid, prolong the period of osmotic stress, and result in subsequent dehydration of blood, amniotic fluid, and embryonic skin. These results show that the regulation of allantoic fluid volume and ion content and the action of the CAM surrounding it are the integral components of the osmoregulatory system of the chick embryo.
In vitro study of the intestinal brush border enzyme activities in developing anuran amphibian: Effects of thyroxine, cortisol, and insulin
Authors: Pouyet J. C. , Hourdry J. 
Published: June 2005

AbstractThe effects of several hormones on intestinal brush border membrane enzymatic activities have been investigated in intestinal explants taken from the amphibian midwife toad at different developmental stages. Explants were treated for at least 2 days with thyroxine (0.1 μg/ml of culture medium) or for 2 days with cortisol (25 μg/ml) or insulin (6 mU/ml). The hydrolases examined were maltase, trehalase, glucoamylase, and alkaline phosphatase. In the explants from tadpoles in prometamorphosis, thyroxine had no effect on hydrolase activities; cortisol increased the activity of only glucoamylase, and insulin increased activity of maltase, glucoamylase, and alkaline phosphatase. When the explants were taken from tadpoles at the beginning of climax, cortisol and insulin generally stimulated the enzyme activities studied. When taken from tadpoles at the end of climax, at the moment when the embryonic cells under the degenerating epithelium divide, cortisol and insulin had little effect on these activities. When the animals terminate their metamorphosis, the intestinal epithelium of the explants is totally newly formed (secondary epithelium). At this time, cortisol stimulated the activities of maltase, glucoamylase, and alkaline phosphatase, while insulin decreased the activities of maltase and glucoamylase.
Biophysical properties of the zona pellucida measured by capillary suction: Is zona hardening a mechanical phenomenon?
Authors: Drobnis Erma Z. , Andrew Jane B. , Katz David F. 
Published: June 2005

AbstractFollowing fertilization, the zona pellucida, a glycoprotein shell investing mammalian eggs, becomes more resistant to dissolution by various agents. This decreased solubility, termed zona hardening, does not occur in hamsters. Thus, universal roles of zona hardening in the block to polyspermy and in oviductal interaction with embryos have been discounted. Although these roles probably have mechanical components, zona hardening has been assessed only as decreased solubility. In our studies, mouse and hamster ovulated oocytes were compared with 2‐cell embryos by capillary suction. Step changes in pipet pressure were measured manometrically while resulting zona deformations were determined videomicrographically. Both mouse and hamster zonae were more “deformable” in oocytes than embryos. These results suggest that mechanical zona hardening may be a universal phenomenon. In addition to zona hardening following fertilization, a “spontaneous” zona hardening phenomenon has been reported for mouse oocytes (not embryos) cultured in vitro. In our system, this spontaneous decrease in zona solubility by protease was not accompanied by a mechanical change. In contrast, hamster oocyte and embryo zonae became slightly more soluble, and considerably more deformable during 4‐h culture. Thus, spontaneous zona hardening is not a universal phenomenon, and, while decreased solubility has been called “hardening”, it is not always accompanied by a mechanical change.
The effects of water‐soluble vitamins on the expansion of rabbit blastocysts in vitro
Authors: Kane Michael T. 
Published: June 2005

AbstractThe vitamin requirements for culture of rabbit morulae to expanded blastocysts were examined. Early morulae were cultured for 5 days either in a control complete medium containing all the 11 water‐soluble vitamins of F10 culture medium (biotin, pantothenate, choline, inositol, niacinamide, pyridoxine, riboflavin, thiamine, folic acid, B12, and lipoic acid) or in media with each vitamin omitted individually. Blastocyst diameters were measured at the end of culture. The omission of inositol, pyridoxine, riboflavin, and niacinamide resulted in large statistically significant decreases in blastocyst expansion. The omission of B12 resulted in a significant increase in blastocyst expansion indicating that the level present in F10 is toxic to rabbit blastocysts.
Analyses of epididymal sperm surface antigens by monoclonal antibodies against hamster spermatozoa
Authors: Koyama Koji , Kameda Kinu , Ishida Yuzo , Shigeta Minoru , Isojima Shinzo 
Published: June 2005

AbstractBALB/c mice were immunized with spermatozoa from cauda epididymides of hamsters and the immune spleen cells were fused with mouse myeloma cells (P3U1). Seven hybridomas (GHS‐1,‐2,‐3,‐4,‐5,‐6, and ‐7) that produced monoclonal antibodies (Mabs) binding to the epididymal spermatozoa were established. Three Mabs (GHS‐3,‐4, and ‐6) were IgM and the other four were IgGl. All Mabs reacted to hamster spermatozoa from cauda epididymides but none of the Mabs except GHS‐5 and ‐7 reacted to spermatozoa in testis. GHS‐5 and ‐7 Mabs bound to the acrosome region of spermatozoa in both testis and epididymis. The antigens corresponding to GHS‐2, ‐4, and ‐6 Mabs appeared to be excreted from epithelial cells of caput epididymis, while those to GHS‐1 and ‐3 Mabs seemed to be produced in cauda epididymis. Both groups of the antigens bound to the surface of spermatozoa during their epididymal transit. Immunoblotting analyses of epididymal fluid showed that the antigen epitopes corresponding to GHS‐1,‐2,‐3,‐4, and ‐6 Mabs were distributed to multiple components with different molecular weights ranging from over 100 to 25 kd. The distribution patterns of the epitopes corresponding to GHS‐1 and ‐3 Mabs and GHS‐2,‐4, and ‐6 Mabs were very similar, respectively, but each group pattern was quite different from each other. GHS‐5 Mab reacted to a component of sperm extract with a molecular weight of around 94 kd, while GHS‐7 Mab failed to recognize any components transblotted.
Effects of epinephrine on branchial and renal calcium handling in the rainbow trout
Authors: Perry S. F. , Verbost P. M. , Vermette M. G. , Flik G. 
Published: June 2005

AbstractAcute exposure of rainbow trout (Salmo gairdneri) to low external calcium (25 μM) caused an immediate but transient increase in plasma epinephrine concentration that may have been related to a concomitant depression of blood pH. Intra‐arterial infusion of epinephrine at normal ambient calcium levels (0.35 mM) for 4 h caused circulating levels of epinephrine to rise from 2.9 × 10−9 to 8.0 × 10−8 M but did not affect norepinephrine levels, or branchial unidirectional calcium fluxes. Active (ATP‐dependent) calcium transport across basolateral plasma membranes prepared from gill epithelial cells was not affected by pretreatment of fish with epinephrine or by direct application of epinephrine or cAMP, in vitro. Epinephrine infusion elevated urine flow rate, decreased urine pH, and increased urine phosphate levels significantly. Net renal calcium efflux increased significantly as a result of the increased urine flow rate. It is concluded that epinephrine does not stimulate branchial calcium uptake or renal conservation of calcium in rainbow trout at normal external calcium levels and therefore we cautiously suggest that epinephrine is unlikely to be involved in calcium balance during periods of exposure to low external calcium. Instead, epinephrine may play a role in compensating the acid‐base disturbances and the increased branchial water influx that are associated with exposure to low ambient calcium.
Purification and partial characterization of protamines from the European pond turtle, Emys orbicularis
Authors: Elsevier Susan M. , Pieau Claude 
Published: June 2005

AbstractBasic chromosomal proteins were purified from spermatozoa of the European pond turtle, Emys orbicularis. They were partially characterized and classified as type 1 protamines according to the definition of Bloch ([1969] Genetics suppl., 61:93–111; [1976] In: Handbook of Genetics. R.C. King, ed. Plenum Press, New York, Vol. 5, pp. 139–167). Contrary to a previous report (Kharchenko et al., [1980] Biochemistry [Engl. Transl. Biokhimiya], 45:1239–1246), these proteins could also be isolated from Emys testis, but only during certain periods of the male seasonal reproductive cycle. The proteins migrated during gel electrophoresis similarly to the protamines that have been observed for lizards and snakes, members of a different reptile order (Kasinsky et al., [1978] J. Exp. Zool., 203:109–126). These results extend the observation that protamine type is conserved among reptile species and provide a partial characterization of the conserved proteins. They support the conclusion that an important step in the evolution of vertebrate protamines occurs with reptiles. They draw into question, however, hypotheses that have been offered to explain the mechanism bringing about this protein conservation.
Formation and structure of the acrosomal filament in the sperm of Sicyonia ingentis
Authors: Griffin Fred J. , Shigekawa Katherine , Clark Wallis H. 
Published: June 2005

AbstractThe sperm of the natantian Sicyonia ingentis are nonmotile, unistellate cells. During sperm‐egg interaction, they undergo a biphasic acrosome reaction (exocytosis of an acrosomal vesicle and formation of an acrosomal filament). Formation of the acrosomal filament is temporally separated from acrosomal exocytosis by 10–20 min in vivo and 30–45 min in vitro. The acrosomal filament is composed of 1) the filament proper and 2) an extended saucer/petal complex. The filament proper is 0.3–0.5 μm in diameter, about 10 μm in length, and contains tubular‐like structures that do not resemble microtubules. The acrosomal filament terminates anteriorly in the extended saucer/petal complex, a dense conical structure that flares out into 12–15 petal‐like extensions. The extended saucer/petal complex is present in the subacrosome prior to filament formation and during elongation of the filament proper (which occurs over a time span of 3–5 min) is pulled/pushed away from the main body of the sperm.
Calcium dependence of human sperm fertilizing ability
Authors: Mortimer D. , Chorney M. J. , Curtis E. F. , Trounson A. O. 
Published: June 2005

AbstractThe Ca2+ dependency of human‐sperm fertilizing ability was investigated using a modified Tyrode's medium either containing 2.4 mM CaCl2 (CA medium) or with the CaCl2 replaced by SrCl2 and 0.1 mM EGTA added to chelate any residual Ca2+ ions (SREG‐medium). Ten washed sperm populations incubated in either medium for 0, 6, and 22 hours showed the same occurrence of acrosome reactions (by fluorescent lectin labelling and triple stain). A further 3‐hour incubation after washing into fresh CA medium resulted in only a slight increase in acrosome reactions in both media. Eight sperm populations preincubated overnight in CA and SREG media were coincubated for 1 hour with previously salt‐stored human zonae pellucidae also in the same media. Significantly more motile spermatozoa were bound to more of the zonae in CA medium (53.9% vs. 27.6% of zonae with 13.8 vs. 4.3 sperm/bound zona). In three hamster egg penetration test (HEPT) experiments, sperm populations preincubated overnight in either CA or SREG media were coincubated with hamster oocytes prepared in the same media. Only 2.1% of oocytes (1.0 polyspermy) were penetrated in SREG medium, cf., 30.9% of oocytes (1.3 polyspermy) in CA medium. These results demonstrate that while Sr2+ ions can substitute fully for Ca2+ in the capacitation and acrosome reaction of human spermatozoa, sperm‐zona, and sperm‐oolemma interaction seem to involve some more Ca2+‐specific processes). Furthermore, the increased HEPT fertilizing ability of human spermatozoa using overnight preincubation in SREG medium and CA medium for the test cannot be explained on the basis of differential kinetics of capacitation or the acrosome reaction.