bluuebunny/crossref_metadata_2025 huggingface dataset:
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

The 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

The 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

Pale 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

The 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

The 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

Following 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

The 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

BALB/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

Acute 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

Basic 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

The 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

The 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.
Identification of avidin‐interacting proteins in Spisula oocytes: Correlation with germinal vesicle breakdown
Authors: Haneji Tatsuji , Koide Samuel S.
Published: June 2005

Peroxidase‐conjugated avidin was used to determine the presence of avidin‐interacting proteins in Spisula oocytes. By a transblot method, avidin‐peroxidase conjugate interacted with the two proteins with estimated molecular weights of 70,000 and 118,000 in the cytosolic fraction of Spisula oocyte. The reaction with the same proteins in the particulate fraction was considerably reduced. None or weak reaction occurred with proteins prepared from Spisula muscle, sperm, and body fluid. With Arbacia oocytes or hen egg‐yolk and egg‐white proteins, the reaction was minimal or none, respectively. When the avidin‐peroxidase conjugate was preincubated with biotin, its stain‐ ing activity was lost, suggesting that the interacting proteins probably contain biotin.

To determine whether avidin‐interacting proteins are involved in oocyte maturation, Spisula oocytes were treated with 50 mM KCl or 5 μM serotonin to induce germinal vesicle breakdown (GVBD). The staining reaction with the 70,000‐ and 118,000‐dalton proteins in the samples prepared from oocytes treated with KCl or serotonin was greatly intensified and an additional protein with an estimated molecular weight of 220,000 was stained. The occurrence of avidin‐interacting proteins in Spisula oocytes was further verified by the positive staining reaction with a cytochemical method using fluorescein isothiocyanate (FITC)‐conjugated avidin.
Hemocyanin structure changes during early development of the crab Cancer productus
Authors: Wache Susanne , Terwilliger Nora B. , Terwilliger Robert C.
Published: June 2005

Hemocyanin is present in oocytes and embryos of the brachyuran crab Cancer productus. Oocyte hemocyanin, like adult crab hemocyanin, exists as two hexamer (25S) and single hexamer (16S) aggregates. The two hexamer molecule is composed of at least four electrophoretically distinct subunits. The electrophoretic properties of oocyte hemocyanin subunits are indistinguishable from those of the corresponding adult hemocyanin. Evidence is presented that oocytes could take up maternal hemocyanin through endocytosis. Hemocyanin present in the developing embryo also exists as two hexamer and hexamer aggregates. However, the embryo two hexamer hemocyanin shows an electrophoretic pattern of subunits different from that of maternal or oocyte two hexamer hemocyanin. These data, together with previous studies on other species of decapod crustaceans, indicate that hemocyanin different from the adult molecule is produced after fertilization of the egg.
Patterns of cholinesterase staining during neural crest cell morphogenesis in mouse and chick embryos
Authors: Martins‐Green M. , Erickson C. A.
Published: June 2005

Cholinesterase (ChE) activity has been reported previously in nonneuronal tissues of a variety of avian and mammalian embryos. We report here a comparison study of ChE staining in chick and mouse embryos. Transmission electron microscopy was used to study the distribution of this activity in neuroepithelial, neural crest, somite, and ectodermal cells. Our cytochemical studies show that the distribution of nonspecific ChE staining in these tissues during neurulation is similar in the two species but that acetylcholinesterase (AChE) staining, previously shown to be intense in the chick, is absent in the mouse; the only cells showing the presence of this enzyme at these stages of development in mouse are blood cells. However, AChE staining does appear later in the brain, in neural tissues derived from the neural crest and, perhaps, in some migratory neural crest cells. The differences between AChE distribution in these two species (and that reported previously in the rabbit) indicate that the timing of first appearance of AChE is unrelated to neuroepithelial morphogenesis or to neural crest cell motility. The correlation between nonspecific cholinesterases and morphogenetic movements, however, is supported by these studies.
Reversing cytoplasmic flow in nucleated, constricted sand dollar eggs
Authors: Rappaport R. , Rappaport Barbara N.
Published: June 2005

The purpose of this investigation was to study the nature of the immediate response of the surface to the mitotic apparatus in sand dollar (Echinarachnius parma) eggs. The normal geometrical relationship was changed by snaring fertilized eggs between opposed, overlapping hooks and constricting the eggs to reshape them into two partial spheres joined by a constricted neck about 27 μm in diameter. When both asters of the mitotic apparatus lay on the same side of the constriction, cytoplasm flowed out of the nucleated part across the constriction, beginning about 30 min before anticipated cleavage time. After the asters moved across the constriction, the direction reversed, and reversal usually occurred several times before cleavage (n = 18). The average time between beginning of flow in one direction and beginning of flow in the opposite direction was 7.7 min (n = 23). Cells were bisected and constricted to determine the role of the mitotic apparatus. Bisected cells with two asters behaved like constricted normal cells (n = 15). Cells with no mitotic apparatus developed no cytoplasmic flow (n = 11). In cells with one aster, flow most often occurred within ten min of anticipated cleavage time (n = 14). When whole constricted eggs were treated with Cytochalasin B at the minimum concentration that blocks cleavage in normal eggs (3 μg/ml), neither cytoplasmic flow nor cleavage occurred, although the mitotic apparatus developed normally.

Cytoplasmic flow in constricted eggs in cleavage stages requires asters and functional actin‐associated cytoskeleton. The results suggest that the asters cause an increase in tension in nearby surfaces.
Fertilization of zona‐drilled mouse oocytes treated with a monoclonal antibody to the zona glycoprotein, ZP3
Authors: Conover J. C. , Gwatkin R. B. L.
Published: June 2005

Opening a small aperture in the zona pellucida of mouse oocytes by using micromanipulation and a stream of acidified Tyrode's solution (zona drilling) improved the efficiency of in vitro fertilization at low sperm concentrations without adversely affecting development to the blastocyst stage. Zona drilling also permitted in vitro fertilization and development when sperm penetration through the zona was blocked by a monoclonal antibody to the protein core of the zona glycoprotein, ZP3. These results provide a direct demonstration that sperm entry occurs through the aperture and also suggest that zona drilling of human oocytes may offer a therapeutic approach when autoantibodies to the zona pellucida are suspected as a cause of infertility.
Antisera probes to an atypical pseudocholinesterase from surgeonfish reveal immunochemical variability and tissue‐specific molecular polymorphism
Authors: Leibel Wayne S.
Published: June 2005

Polyclonal antisera were raised in rabbits against the purified sialated, presumedglobular tetrameric pseudocholinesterase (pseudo‐ChE) from surgeonfish (Leibel: Journal of Experimental Zoology 1988b) and against commercially obtained Electrophorus electroplax AChE. The resulting antisera probes were absolutely specific for their respective antigens and failed to titrate ChE activities heterologously. However, each antisera probe did crossreact with its other respective globular and asymmetric aggregational isozymes. The resultant specific probes were then used to examine interspecific evolutionary conservation of the two ChE activities and, in conjunction with velocity sedimentation analysis and differential paraoxon inhibition, the tissue distribution and molecular polymorphism of these same two enzyme systems in surgeonfish.

These experiments suggest the tight evolutionary conservation of AChE in contrast to the apparent high variability of pseudo‐ChE amongst the wide range of teleost fishes tested. The native atypical pseudo‐ChE was shown to exist, like AChE, as a series of sialated and asialated globular and asymmetric aggregational isozymes whose relative distribution exhibits marked tissue specificity. The extremely high levels of pseudo‐ChE characteristic of white skeletal (epaxial) muscle, in particular, was conspicuous, and its occurrence in the sarcolemma is discussed in the context of its possible function and in relation to the apparent lack of evolutionary conservation amongst marine teleosts.
Sites and trend of erythropoiesis in anemic, normal, and splenectomized newts
Authors: Frangioni Giuliano , Borgioli Gianfranco
Published: June 2005

Newts, Triturus cristatus carnifex (Laurenti), were anesthetized by submersion in 2% chlorbutol in tap water for 15 min, splenectomized and then rendered totally anemic two months later by treatment with acetylphenylhydrazine (APH) diluted in their tanks (25 mg/liter for 36 h, changing the solution every 12 h). In the 14 weeks following hemolysis, erythron restoration occurred with the same intermittence as it did in whole animals rendered anemic by APH treatment: Beginning the second week the red blood cell count progressively increases for about one month, followed by a period of stasis which lasts about three weeks, then by a new increase, and then by a final period of stasis. Histological examination shows that erythropoietic activity occurs partly in the circulating blood and partly in erythroblasts nestled in the crypts between the muscular trabeculae of the ventricle as well as in the atrial walls. These cells, which are not part of the freely circulating elements in the blood stream, become very abundant in both whole and splenectomized anemic newts but are also present in normal animals. Newts, thus, have three sites for erythropoiesis: the spleen, the blood stream, and the heart. The other components compensate for the elimination of the spleen without determining any lack of, or delay in, erythropoietic response.
Autoreactive blood cells and programmed cell death in growth and development of protochordates
Authors: Harp James A. , Tsuchida Craig B. , Weissman Irving L. , Scofield Virginia L.
Published: June 2005

The tunicate Botryllus is a marine protochordate whose clonal colonies undergo regulated natural transplantations when they come into contact in nature. The outcome of these transplantations (fusion or rejection) is controlled by genes of a highly polymorphic histocompatibility system that resembles in many respects the mammalian major histocompatibility complex (MHC). While fusion or rejection reactions are often completed within 24 hr after transplantation, resorption of one partner of a pair of fused semiallogeneic colonies may occur days to weeks after initial contact. The latter process is similar to the degeneration of old individuals, or zooids, that precedes maturation of each new generation of asexual buds. Here we describe comparisons of in vitro reactions of (a) mixtures of cells from allogeneic animals and (b) cells taken from animals at the zooid‐resorption (“takeover”) stage of colony development. In vitro autoreactivity of cells from resorbing colonies may reflect in vivo responses to senescent cells, which in turn may be related to allorecognition events that govern fusion or rejection between colonies.
Immediate response to repeated capture and handling of wild impala
Authors: Hattingh J. , Pitts N. I. , Ganhao M. F.
Published: June 2005

The composition of blood from veld and boma (enclosure)‐kept impala, obtained immediately after the animals were manually restrained, was compared to control values. Statistically significant differences existed between the values for hematocrit, lactate, glucose, and osmolarity of veld and boma‐kept animals compared to control data. Cortisol values were significantly greater (P < .05) in boma‐kept animals (93 ± 21 nmol/liter) but not in veld impala (11 ± 3 nmol/liter). It is suggested that the high cortisol and other values measured in boma‐kept impala were due to an anticipatory conditioned response in these animals which occurred prior to them actually being caught. Repeated capture and handling, over a period of several months, of boma‐kept impala resulted in statistically insignificant decreases in the mean values of several variables. Although this is indicative of adaptation it is doubtful whether the animals would ever fully adapt to the procedures involved.
Catecholamine metabolism by the perfused rainbow trout gill
Authors: Colletti A. E. , Olson K. R.
Published: June 2005

The trout gill has the capacity to influence general adrenergic activity through extraction and metabolism of circulating catecholamines (CA); (Nekvasil and Olson, Am. J. Physiol., 1986, 250:R526–R531). To further examine the metabolic process, isolated gills were perfused with 10−8 M and 10−6 M norepinephrine (NEPI) or epinephrine (EPI) and effluent from the arterioarterial (AA) and arteriovenous (AV) pathways analyzed by high pressure liquid chromatography with electrochemical detection (HPLC‐EC). After 20 minutes of continuous 10−6 M NEPI perfusion, metabolites accounted for 70% and 96% of the total amines recovered in the AA and AV effluents, respectively. After 20 minutes of 10−6 M EPI perfusion, 60% and 94% of the amines in the AA and AV effluents, respectively, were metabolites. Similar results were seen during perfusion with 10−8 M CAs. Dihydroxymandelic acid (DHMA) and vanillylamandelic acid (VMA) were the major metabolites identified in gill effluent. Gills perfused with a bolus of 3H‐NEPI extracted 47% of the radiolabel. Continuous perfusion with 10−5 M cocaine or 10−5 M tyramine 30 minutes after the 3H‐NEPI pulse released 3H‐labeled and ‐unlabeled NEPI and metabolites into the AA effluent. Cocaine released more unmetabolized 3H‐NEPI than tyramine, whereas tyramine released more 3H‐labeled metabolites than cocaine. These studies indicate that the gill efficiently inactivates CAs through metabolism and that the major products formed are deaminated (DHMA) and deaminated:O‐methylated (VMA) metabolites. The gill is also able to remove NEPI from the perfusate and store it intact for up to 50 minutes. Branchial uptake of CAs in fish and pulmonary uptake of CAs in mammals appear to have basic similarities.
Effects of two juvenile hormone analogs (R‐20458, RO203600) and three juvenile hormones (JH 1, 2, and 3) on the number and distribution of sensilla on the seventh abdominal tergite in the male German cockroach, Blattella germanica (L.) (Dictyoptera: Blattellidae)
Authors: Wheeler Christine M. , Gupta A. P.
Published: June 2005

Three types of sensilla, s. chaetica B, s. trichoidea, and s. campaniformia were identified on the 7th abdominal tergite of JH‐JHA‐and acetone (control)‐treated adult male Blattella germanica by light and scanning electron microscopy. All contact chemoreceptors (s. chaetica B) and the majority of mechanoreceptors (s. trichoidea) surround the gland openings or cover the tergal modification, which indicates that contact chemoreception and mechanoreception are important in the tergal feeding stage of mating behavior. The numbers of all three types of sensilla were significantly reduced for all five treatments.
Modification of pyruvate kinase from the foot muscle of Patella caerulea (L) during anaerobiosis
Authors: Michaelidis B. , Gaitanaki C. , Beis Is.
Published: June 2005

Pyruvate kinase (PK) from the foot muscle of Patella carulea (L) is present as two variants. These variants are eluted by ion‐exchange chromatography from DEAE‐cellulose as peak I and peak II at different concentrations of KCl. Studies of their kinetic properties show that both variants of PK exhibit sigmoidal curves with respect to phosphoenolpyuvate (PEP), but the PK in peak I is more sensitive to the activation by PEP and fructose diphosphate (FDP) and less sensitive to inhibition by alanine, ATP, and H+ than the PK in peak II. The proportion of the two PK variants changes during anaerobiosis. The ratio of the number of units of enzyme in peak I to that in peak II increases up to the second hour and then decreases up to the eight hour of anaerobiosis. Studies on the electrophoretic mobility of these two variants on strips of cellulose acetate show that the less active from or peak II PK migrates more quickly toward the anode (Rf = 0.13) than the more active from or peak I PK (Rf = 0.07). Peak II PK, after treatment with alkaline phosphatase, exhibits kinetic properties and electrophoretic mobility quite similar to those of peak I PK. The above data suggest that the two variants of PK from the foot muscle of P. caerulea are interconvertible and the direction of the interconversion depends on the duration of anaerobiosis.
Secretion of proteins by cultured bovine oviducts collected from estrus through early diestrus
Authors: Malayer J. R. , Hansen P. J. , Buhi W. C.
Published: June 2005

To characterize in vitro protein secretion by the oviduct throughout early stages of the estrous cycle, 16 cows received a luteolytic dose of PGF2α and were randomly assigned to be killed on day (D) 0, 2, 5, or 8 after subsequent estrus. Explant cultures of oviducts (ampulla and isthmus) were incubated for 24 h at 39°C in a modified Eagle's minimal essential medium supplemented with 50 μCi L‐[4,5‐3H]leucine. Oviductal secretion of de novo synthesized protein measured by incorporation of [3H]leucine into nondialyzable radioactivity in culture supernatants was greatest at D 0 and declined thereafter. Incorporation of [3H]leucine into TCA‐precipitable macromolecules in tissue homogenates was also greatest at D 0. Analysis of culture supernatants by one‐dimensional polyacrylamide gel electrophoresis revealed four major bands of radiolabeled proteins at > 97 kDa, 85–97 kDa, 55 kDa, and 30 kDa. Analysis of individual polypeptides resolved by two‐dimensional polyacrylamide gel electrophoresis indicated that five of 32 individual polypeptides examined were secreted at significantly greater rates at estrus than at other times examined. One of these five polypeptides, a 97‐kDa peptide with an apparent pI of 5.0, was the major secretory product at estrus and accounted for 18% of total radioactivity recovered from two‐dimensional gels. Two of 32 polypeptides examined were secreted at significantly greater rates by explants of the oviduct contralateral to the side of ovulation. In summary, estrus is associated with an elevation in total protein secretion by the bovine oviduct. This increase is due to selective amplification of secretion of several but not all secretory proteins.
A staging system for mouse limb development
Authors: Wanek N. , Muneoka K. , Holler‐dinsmore G. , Burton R. , Bryant S. V.
Published: June 2005

A series of 15 stages of development for the mouse limb bud have been defined, spanning the time from the first appearance of the limb bud to the completion of limb outgrowth. The stages are based on changes in the morphology of the limb in living preparations. The development and regression of the apical ectodermal ridge (AER) as well as the development of the skeletal structures are also described. This staging system has been developed in response to the need to standardize in situ experimental analyses of the mouse limb bud. Comparable stages of the commonly used chick wing and mouse whole embryo systems are presented.
Absence of an electrical block to polyspermy in the scaphopod mollusk Dentalium vulgare
Authors: Moreau M. , Guerrier P. , Dufresne L.
Published: June 2005

We investigated the electrical properties of the egg of the Scaphopod mollusk Dentalium vulgare during fertilization. Following fertilization in natural or artificial sea water, the membrane potential shifts from its resting level (−70, −80 mV) to recurring small depolarizations of 5–20 mV (minispikes). A classical fertilization potential of 60–80 mV amplitude may also occur. However, it does not represent an unescapable event and may even appear as late as 20–40 min after insemination, i.e., when sperm pronuclei are already formed in the egg. Even when it occurs early, and over a long duration, this response cannot block polyspermy, which also occurs after clamping the egg potential at positive or negative values. Moreover, similar responses may appear spontaneously, in the absence of insemination.

In contrast, minispikes are only triggered by the spermatozoon and their amplitude depends on the external Na and Ca concentrations. Their number is the function of sperm density, but always appears in excess over the number of penetrated spermatozoa. Minispikes are not abolished by cytochalasin B (2 μg/ml), which greatly reduces the number of successful sperm penetrations. These data suggest that no voltage‐dependent mechanism limits sperm penetration in the plasma membrane of Dentalium eggs, and that minispikes may result from the opening of individual patches of channels, either triggered by each attached spermatozoon or recurrently stimulated, following sperm penetration.
A morphometric study of bone and tooth volumes in the pipid frog Xenopus laevis (Daudin), with comments on the importance of tooth resorption during normal tooth replacement
Authors: Shaw J. P.
Published: June 2005

Volumetric estimations of teeth and bone on serial sections using a semiautomatic image analyzer indicate that, in the polyphyodont dentition of the pipid anuran Xenopus laevis (Daudin), the mean volume of the dentine composing the teeth is about 23.5% of the volume of the supporting maxillae and premaxillae. During tooth replacement, osteoclasts resorb up to 98% of the dentine. Teeth may be resorbed rather than shed in order to conserve tooth constituents because, if shedding of complete teeth did occur, a quantity of calcified tissue equal to perhaps 45 times the volume of the bone of the upper jaw might be lost over an animal's projected life span of about 13–15 years.
Cytogenetic analysis of ethanol‐induced parthenogenesis
Authors: O'Neill G. T. , Kaufman M. H.
Published: June 2005

The brief exposure of recently ovulated mouse oocytes to a dilute solution of ethanol in vitro for 1, 3, or 5 min induced a uniform high incidence of parthenogenetic activation. The majority of parthenogenones developed a single haploid pronucleus after the extrusion of a second polar body. The proportionate incidence of this parthenogenetic class was significantly reduced as the duration of ethanol exposure increased from 1 min to 5 min. There was a concomitant increase in the incidence of parthenogenones that developed two haploid pronuclei following failure of extrusion of the second polar body. Cytogenetic analysis of the ethanol‐induced single‐pronuclear haploid parthenogenones at metaphase of the first cleavage division clearly demonstrated that a significant proportion were aneuploid. The incidence of aneuploidy observed was directly related to the duration of ethanol exposure. G‐band analysis of the aneuploid metaphases revealed that the chromosomes were not randomly involved in the malsegregation events. This observation may be a reflection of the relationship of particular chromosomes to the meiotic spindle apparatus rather than on any specific property of the agent to which they were exposed. It is believed that ethanol disrupts the organisation of cytoskeletal elements and, in particular, interferes with the processes of chromosome segregation at the second meiotic division.
Ascidian sperm penetration and the translocation of a cell surface glycosidase
Authors: Lambert Charles C.
Published: June 2005

Sperm bind to vitelline coat (VC) glycosides of ascidian eggs by means of a sperm surface glycosidase (Hoshi et al.: Zool Sci 2:65, 1985). In the genus Ascidia, N‐acetylglucosamine (NAG) is the VC ligand. After initial binding by the tip of the head, sperm pass through the VC and perivitelline space leaving the single mitochondrion outside. This process can also be followed in vitro on a coverslip. Analysis of recorded video images shows that the sperm moves away from the anchored mitochondrion. Our model for sperm penetration suggests that mitochondrial translocation is responsible for driving the sperm into the egg. In the work presented here, we have demonstrated that ascidian sperm have N‐acetyl‐β‐D‐glucosaminidase (NAGase) activity with an acidic pH optimum. This enzyme, which can be removed from the sperm with Triton X‐100, binds to concanavalin A, demonstrating that it is glycosylated. Histochemical methods disclose that the enzyme is originally located at the tip of the head but subsequently remains with the surface overlying the mitochondrion during translocation. Fluorescent Con A was used as a second label for localization of the enzyme on the cell surface during translocation. Colocalization of both probes of the enzyme support a crucial facet of our model; the sperm surface VC binding site remains over the mitochondrion during translocation. This would couple mitochondrial translocation with sperm penetration and drive the sperm into the egg.
Seasonality of serum testosterone levels and sperm density in Tursiops truncatus
Authors: Schroeder J. Pete , Keller Karl V.
Published: June 2005

We trained a mature male bottlenose dolphin, Tursiops truncatus, to provide semen samples on command. After completion of the 10‐week training period, semen was collected twice weekly and blood was sampled twice monthly for a period of 28 months. Total sperm per ejaculate ranged from near 0 to 54.6 × 109 (n = 1332). Sperm densities from each session ranged from no sperm to 1,587 × 106/ml (n = 241). Testosterone levels ranged from 1.1 to 54.4 ng/ml (n = 79). Seasonal variations were observed in total sperm per ejaculate, sperm density per ml of ejaculate, and in serum testosterone levels. Peak sperm densities were detected during September and October of three consecutive breeding seasons. Serum testosterone levels peaked in June, decreased during July and August, and were lowest in September and October, the period of greatest sperm density. Peak sperm production and density were coincident with the peak period of breeding activity but at a time when serum testosterone levels were lowest.
Chloride‐type cells in the skin of the metamorphosing bonefish (Albula sp.) leptocephalus
Authors: Pfeiler Edward , Lindley Virginia
Published: June 2005

The skin of metamorphosing bonefish (Albula sp.) larvae (leptocephali) was examined using both scanning (SEM) and transmission electron microscopy (TEM). SEM revealed that surface epithelial cells of larvae that were just entering the metamorphic phase possessed numerous ridges and that epithelial pores occurred randomly at cell junctions. The pores were very similar to those seen in gill tissue of adult marine teleost fishes where they have been shown to represent the apical crypts of chloride cells. TEM confirmed the presence of chloride‐type cells in the epidermis of early metamorphosing larvae that contained both numerous mitochondria and an extensive system of tubules that appeared to be derived from the plasma membrane. SEM of intermediate and advanced metamorphosing larvae showed that the ridged epithelial cells tended to be more disorganized and were possibly degenerating but that epithelial pores were still evident. TEM of the skin of early metamorphosing larvae also showed a loosely organized internal structure in some of the epithelial cells. The ultrastructure of the skin is discussed in terms of the morphological and physiological changes that take place during metamorphosis.
Effects of salts in promoting the adhesion of amphibian gastrula cells
Authors: Komazaki Shinji
Published: June 2005

Presumptive ectodermal and endodermal cells were isolated from the gastrula of the newt Cynops pyrrhogaster, and the effects of salts on embryonic cell adhesion were examined. When the concentrations of NaCl, KCl, MgSO4 and Ca (NO3)2 in the culture medium were increased individually, they all effectively promoted ectodermal cell adhesion. MgSO4 and Ca(NO3)2 promoted endodermal cell adhesion, but NaCl and KCl did not. The culture medium containing increased NaCl (90 mM) nonspecifically promoted ectodermal cell adhesion to the four substrata studied—polystyrene dish, glass, collagen, and fibronectin. The effects of drugs that influence the membrane permeability of Na+ and Ca2+ and the replacement of Na+, Cl−, and Ca2+ with other ions were studied. The results show that the flow of Na+ and Ca2+ into the cytoplasm promotes ectodermal cell adhesion but exerts no influence on endodermal cell adhesion.
Pattern of hemipenis use in the male lizard Anolis sagrei after unilateral castration
Authors: Tokarz Richard R.
Published: June 2005

This study investigated whether sensory feedback from the testis and sperm duct determines the pattern of hemipenis use in male A. sagrei. Males were unilaterally castrated and observed in copulations that began 2 wk after surgery. Independent of whether the left or right testis had been removed, unilaterally castrated males showed no significant difference in the frequency of use of either the left or right hemipenis in either of two copulations separated by 1–3 h or in a series of 16 copulations over 16 days. Thus, males did not preferentially use the hemipenis leading to the intact testis. Moreover, unilaterally castrated males showed significant alternation in the use of the hemipenes, not only in the two successive copulations, but also in the series of 16 copulations. The mass of the sperm ducts differed significantly after the last of the copulations. The mass of ducts that led to a testis was significantly greater than that of ducts not leading to a testis. These findings suggest that the pattern of alternation of hemipenis use in male A. sagrei is not determined by sensory input from either the testis or the sperm duct.
Integumentary uptake of short‐chain carboxylic acids by two freshwater oligochaetes, Tubifex tubifex and Lumbriculus variegatus: Specificity of uptake and characterization of transport carrier
Authors: Sedlmeier Ulrich A. , Hoffmann Klaus H.
Published: June 2005

The freshwater oligochaete Tubifex tubifex can take up considerable amounts of dissolved organic material (DOM) from ambient water (Hipp et al. J. Exp. Zool. 1986; 240:289–297). This paper describes evidence that the uptake system is located in the body wall. The system preferentially transports unsubstituted aliphatic monocarboxylic acids with chain lengths of two and three carbons. The proteinaceous nature of the monocarboxylate “carrier” is suggested by results from studies with covalent inhibitors [α‐cyano‐4‐hydroxycinnamate; para‐chlormercuri‐phenyl‐sulfonic acid (PCMBS)] and by the temperature dependence of transport. The characteristics of the uptake system are similar to those of the systems for transporting monocarboxylic acids in mammals. In another freshwater oligochaete, Lumbriculus variegatus, the rates of uptake of DOM were low and no evidence for a mediated transport system was found.