bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spine regeneration in larvae of the crab, Rhithropanopeus harrisii
Authors: Freeman John A. 
Published: June 2005

AbstractDorsal spines were removed from intermolt first instar larvae of Rhithropanopeus harrisii. The wound was immediately closed by hemocytemediated clot formation. Epidermal cells from regions adjacent to the spine then formed a continuous, single‐cell‐thick layer beneath the clot. During premolt of the first instar, the distal cells formed a new spine tip by apical extensions. Regenerating spines underwent enhanced growth during the first two instars; this resulted in a normal‐sized spine by the third instar. Determination of cell density in regenerating spines indicated that the enhanced growth during reeneration was due to increased cell division during the first two instars. Spine regeneration had no effect on duration of the molt cycle, onset of premolt, or metamorphosis.
The common inhibitory innervation of the pereiopods of the crayfish Cherax destructor
Authors: Cooke Ian R. C. , MaCmillan David L. 
Published: June 2005

AbstractStimulation of either the medial or lateral giant axons in the crayfish (Cherax destructor; Decapoda: Astacura) CNS was found to activate the common inhibitor neuron reliably in each of the pereiopods. This property was used to study the extent of the common inhibitory innervation of the leg muscles, including the muscles of the coxa, basis, and ischium. The common inhibitor was found to innervate all of the muscles of the pereiopod.
Survival of mouse embryos frozen‐thawed slowly or rapidly in the presence of various cryoprotectants
Authors: Miyamoto Hajime , Ishibashi Takehiko 
Published: June 2005

AbstractEight‐cell mouse embryos were frozen by using glycerol, ethylene glycol, or erythritol as the cryoprotectant. The samples were slowly cooled (0.5°C/min) to temperatures between −10 and −79°C before direct transfer to liquid nitrogen (− 196°C) and thawed slowly (∼ 20°C/min) or rapidly (∼ 500°C/min). The highest survival rates of embryos in 1 and 2 M glycerol were obtained after transfer to −196°C from −40 to −79°C, regardless of the thawing rate (72 to 90%), except for those of embryos thawed slowly in 2 M glycerol, in which case highest survival rates were obtained after transfer from −70 and −79°C (78 to 82%). With slow thawing, survival of embryos in 1.2 M ethylene glycol reached maximal levels at transfer temperatures between −50 and −79°C (82 to 89%) and with rapid thawing at transfer temperatures between −40 and −79°C (84 to 90%). The highest survival rates of slowly thawed embryos in 0.6 M erythritol were obtained after transfer to −196°C from −35 and −40°C (53 to 55%) and of rapidly thawed embryos after transfer from −30°C (46%). These results show that the transfer temperatures to liquid nitrogen, at which the highest survival rates of mouse embryos are obtained, vary with the cryoprotectant and the thawing rate. It appears that with glycerol and ethylene glycol mouse embryos are less sensitive to the thawing rate when slowly cooled to lower subzero temperatures before rapid cooling.
Serotonin or its agonist 5‐methoxytryptamine can stimulate hamster sperm acrosome reactions in a more direct manner than catecholamines
Authors: Meizel Stanley , Turner Kenneth O. 
Published: June 2005

AbstractSerotonin (50 μM) or its agonist 5‐methoxytryptamine (5 μM) stimulated the acrosome reactions of golden hamster sperm within 15 min after addition to sperm capacitated in vitro for 4.5 h. The stimulation was inhibited by the serotonin receptor antagonists quipazine or cyproheptadine. Epinephrine (70 μM), norepinephrine (50 μM), and dopamine (25 μM) were unable to stimulate acrosome reactions even at 30 min under the same conditions, even though previous studies had demonstrated stimulation by these catecholamines at the same concentrations when present from the start of the capacitation time course. Epinephrine (5 μM) also was unable to stimulate at 30 min. These results demonstrate that serotonin and its agonist have a more direct effect on the hamster sperm acrosome reaction than other biogenic amines and that the effect is receptor‐mediated.
Rhythmic contractions of the blastoderm of the medaka Oryzias latipes, a teleost
Authors: Fluck R. , Gunning R. , Pellegrino J. , Barron T. , Panitch D. 
Published: June 2005

AbstractThe blastoderm of the medaka embryo contracts rhythmically during epiboly; the time for a contractile wave to move over the entire blastoderm is about one minute at 25°C. The primary objective of this study was to determine which layer(s) of the blastoderm participate in these contractions. We watched changes in the shape of wounds in the enveloping layer (a simple epithelium that covers the blastoderm), contractions of embryos in which the segmentation cavity had been inflated with saline media, and the movement of embryos from which the enveloping layer had been surgically removed. We conclude that both the enveloping layer and the underlying yolk syncytial layer participate in the contractions. The contractions were inhibited by cytochalasin B (5 or 10 μg/ml), by introducing 100 mM K+ into the segmentation cavity, and by bubbling carbon dioxide through the bathing medium. Elevating the [K+] in the external medium had no apparent effect on the contraction nor did adding the cholinergic antagonists, atropine and d‐tubocurarine, to either the bathing medium or the segmentation cavity. We conclude that microfilaments are involved in the contractions, and we discuss the possibilities that changes in the membrane potential of the cells may precede or accompany the contractions and that the contractile waves may be preceded by signals propagated through gap junctions. We conclude, furthermore, that acetylcholine has no role in either the initiation or the propagation of the contractile waves. An improved method for dechorionating medaka embryos, based on previously published protocols, is described. With this method, embryos can be dechorionated in 3 hours and can be obtained as young as blastulae.
Assessment of mutagenic damage following ethyl methanesulfonate mutagenesis in the axolotl (Ambystoma mexicanum)
Authors: Armstrong John B. , Fletcher William S. 
Published: June 2005

AbstractWhen male axolots (Ambystoma mexicanum) were treated with 100 mg/liter of ethyl methanesulfonate (EMS), a dominant lethal effect was obtained. Embryonic survival of Fl progeny was most severely reduced between about 50 and 150 days after treatment. Dominant lethal lesions probably consist of chromosome breaks that lead to loss of parts of chromosomes or entire chromosomes. The appearance of embryos with a single nucleolus was used to assess this type of damage. The peak incidence of such embryos coincided with the peak of dominant lethality. At 25 mg/liter EMS, there was no significant dominant lethal effect, but as many as one‐fourth of the embryos appeared morphologically abnormal during the period between 50 and 120 days after treatment. A small but significant number of embryos with a single nucleolus were also obtained.To assess possible recessive lethal damage, androgenetic haploids were produced from some of the mutagenized males. A broad trough of reduced haploid survival was obtained at 100 mg/liter, suggesting that damage is produced in most or all spermatogenic stages. At 10 mg/liter, where there was no dominant lethal effect or significant incidence of embryos with a single nucleolus, a broad period of reduced haploid survival was also obtained. Though we cannot exclude the possibility that chromosome abnormalities contribute to the reduced haploid survival, even at this low dose, the type of damage being assessed is almost certainly less severe than that leading to dominant lethality.
Annual cycle of body size and blood parameters of the aquatic adult red‐spotted newt, Notophthalmus viridescens
Authors: Pitkin Ruthanne Batcheller 
Published: June 2005

AbstractA minimum of 20 aquatic, adult Notophthalmus viridescens were captured approximately every other month during 1980 in order to investigate seasonal changes in body size and blood parameters. Hemoglobin concentration, hematocrit, mean cell hemoglobin, sex, weight, snout‐to‐tail length, snout‐to‐vent length, and the presence of trypanosomes on blood smears were determined. Environmental variables measured included temperature (range 5–26°C), oxygen concentration (range 5.7–12.2 mg/L), and pH (range 6.5–7.5) of water at the pond's edge. Three anemic specimens (< 0.03 gHb/100 ml blood) were found. The only significant (P < 0.05) seasonal effects were that the mean hematocrit of the July sample was greater than that of the March sample and the incidence of trypanosome infection of the March collected newts was lower than those collected in May, July, and August. Significant (P < 0.01) linear relationships were found within the body size and blood parameters but not between them. Females had significantly (P = 0.000) higher hematocrits than males. The hemoglobin concentration and hematocrit did not correlate with the assumed seasonal oxygen demands of the newt.
Glucose‐6‐Phosphate dehydrogenase isozymes in fish—a comparative study
Authors: Kidder Gerald M. 
Published: June 2005

AbstractThe electrophoretic distribution and substrate specificities of isozymes of glucose‐6‐phosphate dehydrogenase (E.C. 1.1.1.49) were studied in seven species of teleost fish. The fish examined included two species of bonefish, Albula neoguinaica and A. glossodonta (Albulidae, Anquilliformes) (Shaklee and Tamaru, '81), and five representatives of the order Perciformes: two species of but‐terflyfish, Chaetodon miliaris and C. aurega (Chaetodontidae); a goatfish, Upeneusarge (Mullidae); a goby, Bathygobius fuscus (Gobiidae); and a snapper, Pristipomoides filamentosus (Lutjanidae). After horizontal starch gel electrophoresis, gel slices were stained using a variety of substrates and cofactors. In all species except the goby, two groups of isozymes were distinguished, corresponding to the mammalian G6PD (specific for glucose‐6‐phosphate (G6P) and NADP+) and H6PD (capable of utilizing galactose‐6‐phosphate and in certain cases other monosaccharide phosphates in addition to G6P). None of the five visible isozymes in the goby was specific for G6P. In each of the other species a single G6P‐ and NADP + ‐specific isozyme was noted, having the most rapid mobility toward the anode. In addition, it was found that all of the isozymes in all of the fish examined could catalyze the oxidation of fructose‐6‐phosphate at a rate comparable to that for G6P, suggesting that glucose‐6‐phosphate dehydrogenase can obviate the role of glucosephosphate isomerase in monosaccharide metabolism.
Erythropoiesis in the developing rainbow trout, Salmo gairdneri irideus: histochemical and immunochemical detection of erythropoietic organs
Authors: Iuchi Ichiro , Yamamoto Masamichi 
Published: June 2005

AbstractIn the rainbow trout, Salmo gairdneri irideus, round, disc‐like erythrocytes in the embryonic circulation (Ery L) are replaced by small, elliptical, disc‐like erythrocytes (Ery ImA) after hatching. In the peripheral blood of alevins, Ery ImAs grow into mature, adult erythrocytes (Ery A) of large elliptical, disc‐like shape (Iuchi, '73b; Yamamoto and Iuchi, '75). Ery L and Ery A have larval and adult hemoglobins, respectively (Iuchi, '73a). The ontogenetic sequence of hemoglobin switching and erythrocyte replacement during erythropoiesis was examined by o‐dianisidine histochemistry as well as immunohistochemistry using FITC‐antibody probe specific to adult hemoglobins.The first phase of embryonic erythropoiesis (for Ery L) occurs in the intraembryonic “intermediate cell mass” as well as the extraembryonic blood islands on the yolk sac. This phase of erythropoiesis is transient, continuing during the 7th to 12th day after fertilization and ceasing by the 15th day (5th day before hatching).There is a mixed population of Ery L, ImA, and A in the peripheral blood of posthatching alevins. Ery ImA and A showed immunofluorescence with FITC anti‐Hb A antibody but Ery L did not. Erythroid cells, stainable with FITC anti‐Hb A antibody, were observed in the kidney and the spleen 1 day before hatching and thereafter, but not in the liver throughout all stages examined. Therefore, we conclude that new erythropoiesis (erythropoiesis for Ery ImA and Ery A) began in the kidney and the spleen 1 day before hatching. These findings indicate that hemoglobin switching during the ontogeny of rainbow trout is based on erythrocyte replacement, correlated with a shift in the site of erythropoiesis from one organ to another.
Release of calcium from bone in vitro by homogenates of embryonic chick parathyroid glands
Authors: Rosen Vicki , Clark Nancy B. 
Published: June 2005

AbstractParathyroid glands were removed from chick embryos of 12 to 20 days of development and tested for their ability to stimulate calcium release from calcium‐45‐labeled embryonic chick bone in organ culture. All glands stimulated calcium‐45 release to approximately the same degree, although the glands of 16‐ and 20‐day embryos had a somewhat enhanced calcium‐mobilizing ability. It appears that parathyroid hormone is present in the embryonic chick coincidental with the time of early development of the skeleton and is present in similar quanities throughout the remainder of embryogenesis.
Melanophores of Zacco temmincki (teleostei) are light sensitive
Authors: Iga Tetsuro , Takabatake Ikuo 
Published: June 2005

AbstractThe responses of melanophores of a cyprinid fish Zacco temmincki to changes in illumination were examined in isolated scale preparations of the adult fishes. Melanosomes in the melanophores aggregated in darkness and dispersed in light. These responses were invariably induced, even in denervated melanophores. These light responses, the dark‐induced aggregation and the light‐induced dispersion, were not affected by a number of alpha and beta adrenergic blocking agents. It was concluded that the melanophores of Zacco temmincki were themselves light sensitive and responded directly to light by melanosome translocations. The light responses were quantitatively assessed in relation to the intensity of illumination.
Changes in polyamine content during limb regeneration in adult Xenopus laevis
Authors: Kurabuchi Shingo , Matsuzaki Shigeru , Inoue Sakae 
Published: June 2005

AbstractPolyamine contents in the regenerates were determined at various stages after amputation of the forelimbs of the adult female Xenopus laevis. Putrescine, spermidine, spermine, and sym‐homospermidine were detected in all the specimens examined. Cadaverine was detected only in a limited number of samples. At 5 days after amputation of forelimbs, well before the formation of regenerates, the putrescine content in the stump tissues increased, followed by the increase in spermidine content.The putrescine level in the forelimb regenerates was highest between 30 and 50 days after amputation, and then decreased. The spermidine concentration in the regenerates was about 20 times greater than that in intact forelimbs all throughout the experiments. The concentration of spermine was initially lower than that of both putrescine and spermidine and further decreased soon after amputation. The concentration of sym‐homospermidine was originally very low and increased slightly during regeneration. The significance of these results, with respect to the function of polyamines in forelimb regeneration of Xenopus laevis, is discussed.
The relationship among ovarian condition, steroid hormones, and estrous behavior in Anolis carolinensis
Authors: Jones Richard E. , Guillette Louis J. , Summers Cliff H. , Tokarz Richard R. , Crews David 
Published: June 2005

AbstractThe lizard Anolis carolinensis ovulates a single egg alternately from each ovary every 14 days. The ovulated egg enters the ipsilateral oviduct, acquires a shell, and is oviposited 18 or 19 days later. Thus, there is only a single egg in one of the oviducts (one‐egg condition) during most of the estrous cycle, but there is a 4–5‐day period when a mature, shelled egg is in one oviduct while a recently ovulated egg is in the contralateral oviduct (two‐egg condition). Analysis of ovarian follicular diameters indicates that the largest follicle in a single ovary exhibits a growth spurt about halfway through its 28‐day vitellogenic growth phase. The corpus luteum, once formed from the ovulated follicle, exhibits a linear decrease in weight, becoming fully regressed just before oviposition of the egg in the ipsilateral oviduct. Plasma concentrations of estradiol‐17β and progesterone are high in two‐egg animals. After oviposition, plasma concentrations of progesterone are still high in one‐egg animals whereas those of estradiol‐17β are much lower. These ovarian and hormonal changes during the estrous cycle are discussed in relation to the probable sources of estradiol‐17β and progesterone, the control of the alternating pattern of ovulation and oviposition, and the role of steroid hormones in female sexual receptivity in this species.
Acetylcholinesterase activity in embryonic and larval development of Artemia salina leach (crustacea phyllopoda)
Authors: Raineri M. , Falugi C. 
Published: June 2005

AbstractAcetylcholinesterase (AChE) activity has been studied in Artemia salina embryos and larvae by quantitative, histochemical, and electrophoretic methods. An AChE activity is present in dehydrated encysted gastrulae and remains low in rehydrated developing embryos, showing at hatching an increase that becomes faster during the nauplius stages (twice the gastrula activity at the nauplius II stage), and continues linearly in the first metanauplius stages. The histochemical staining, faint and diffuse in dehydrated gastrulae, in more advanced embryos becomes localized in cell membranes and stronger in differentiating tissues; most AChE activity is localized in the nervous and muscular cells, and a fainter one in the differentiating metanauplius segments. Dehydrated cysts show one electrophoretic AChE band, that is no longer detectable in rehydrated embryos and larvae, while two other bands appear, that migrate more slowly; in advanced larval stages, the more cathodic band is predominant. In dehydrated cysts, isoelectric focusing separates three AChE bands with isoelectric points (IP) at pH 5.0, 5.7, and 5.9; in hydrated embryos and larvae, the band at pH 5.0 is absent and another is seen at pH 5.5. Eserine, DFP, and BW284c51 inhibit the enzyme activity strongly and cause paralysis of larvae; also tubocurarine blocks the motility. These results are discussed in relation to the differentiation of the neuromuscular system and to the development of motility. As a hypothesis, in early embryonic stages, before any neuromuscular differentiation is evident, a cholinergic‐like system might regulate non‐neural cell activities and interactions, associated with embryogenetic events.
The time course of seawater acclimation in Fundulus heteroclitus L.
Authors: Jacob William F. , Taylor Malcolm H. 
Published: June 2005

AbstractSerum Na+ and osmolality increased significantly within 12–24 hours after transfer of Fundulus heteroclitus to seawater (SW) but returned to freshwater (FW) levels after 4 days in SW. Na+K+‐adenosine triphosphatase (ATPase) remained low during the first 2 days in SW but increased to a level characteristic of fully acclimated fish within 4 days. Serum cortisol did not display a marked elevation during the rise in Na+K+‐ATPase. Thus, the pattern of SW‐acclimation in F. heteroclitus is similar to that of the eel (Anguilla rostrata), but acclimation is accomplished somewhat more rapidly in F. heteroclitus and the prolonged period of elevated serum cortisol observed in the eel does not occur.A distinct peak in cortisol was observed during acclimation to FW when gill Na+K+‐ATPase and serum osmolality were declining. This indicates that elevated serum cortisol does not always lead to an increase in Na+K+‐ATPase activity.
Regulation of the tricarboxylic acid cycle in sea urchin eggs and embryos
Authors: Mita Masatoshi , Yasumasu Ikuo 
Published: June 2005

AbstractContents of the tricarboxylic acid (TCA) cycle intermediates, coenzyme A (CoA) derivatives, and carnitine derivatives were estimated in the developing eggs and embryos of the sea urchin, Anthocidaris crassispina. Levels of the TCA cycle intermediates in unfertilized eggs were similar. The level of malate increased remarkably after fertilization and reached a plateau just before hatching out. Slight elevation in the level of citrate was also observed during early development. These suggest that metabolism of citrate and malate is altered during development. Long‐chain fatty acyl‐CoA was accumulated in unfertilized eggs. Its level decreased after fertilization, then gradually increased until the late gastrula stage and turned to decline. Free CoA level increased after fertilization and reached a peak around the gastrula stage, and thereafter it decreased, while short‐chain acyl‐CoA level decreased gradually after fertilization. Crude citrate synthase from sea urchin unfertilized and fertilized eggs was inhibited by palmitoyl‐CoA, though malate dehydrogenase was not inhibited. The palmitoyl‐CoA‐caused inhibition of citrate synthase was also relieved by spermine and spermidine. In view of the inhibition of citrate synthase by palmitoyl‐CoA at concentrations in unfertilized eggs, the enzyme is probably inhibited in unfertilized eggs by long‐chain acyl‐CoA and released from the inhibited state by the decrease in the level of long‐chain acyl‐CoA and the increase in the level of polyamines following fertilization.
The role of the yolk syncytial layer in determination of the plane of bilateral symmetry in the rainbow trout, Salmo gairdneri Richardson
Authors: Long Wilbur L. 
Published: June 2005

AbstractTwo types of morphogenetic cell movements are required for construction of a teleost embryo from the blastodisc. These are epiboly and convergence. Convergence is responsible for building the embryonic shield, thereby converting the radially symmetrical blastodisc to a bilaterally symmetrical one. Control of the convergence movement in rainbow trout, Salmo gairdneri, blastodiscs was investigated by marking the plane of bilateral symmetry with chalk. The blastodiscs were removed from their underlying yolk syncytial layers (YSL) and younger, radially symmetrical, blastodiscs were used to replace them. The newly transplanted blastodiscs formed planes of bilateral symmetry which matched the marked YSL substratum. Therefore, the YSL from an older, bilaterally symmetrical egg can impart its bilateral symmetry to a young, radially symmetrical blastodisc. This ability suggests that the YSL has the role of directing the cell movements which establish the embryonic shield during normal morphogenesis.
The relationship between the presence of cysteine lyase in the yolk sac endoderm and the disposition of the area vasculosa in the chicken blastoderm
Authors: Vanroelen Ch. , Vakaet L. 
Published: June 2005

AbstractTwo series of experiments were carried out to test the possible relationship between the presence of cysteine lyase and area vasculosa in the chicken blastoderm. In the first series, the localization of cysteine lyase was compared with the disposition of the area vasculosa at the successive stages of gastrulation and neurulation. In definitive streak stage chicken blastoderms, the enzyme first appeared laterally at the area pellucida–area opaca border. At older stages, this positivity extended rostrally and only finally did it appear in the caudal area. Based on these in toto observations, the relationship with area vasculosa, the distribution of which has been studied by Settle ('54), seems only incidental. In the second series, intermediate streak stage blastoderms were transversely dissected so that the rostral part did not contain any mesodermal component. The presence of cysteine lyase in this rostral part after 15 hr of culture suggests that the appearance of cysteine lyase in the yolk sac endoderm is not dependent upon the presence of area vasculosa. Moreover, the results suggest that the yolk sac endoderm of the chicken blastoderm is determined to produce cysteine lyase from the intermediate streak stage on.