bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sporadic appearance of histones, histone‐like proteins, and protamines in sperm chromatin of bony fish
Authors: Saperas Núria , Lloris Domènec , Chiva Manel 
Published: June 2005

AbstractIn this work we study the presence and the composition of 24 species of bony fish, representing 18 families and 7 orders of teleosts. The species studied belonging to orders Clupeiformes and Lophiiformes display typical protamines, whereas the species belonging to orders Notacanthi‐formes, Gadiformes, and Ophiidiformes contain histones instead of protamines in their sperm nuclei. In these species, one or more specific proteins are added to the pattern of canonical histones and, in the cases that have been analysed compositionally (Merluccius capensis, Cataetyx laticeps), the specific proteins seem to be related to histones. Among the order Scorpaeniformes, the species Helicolenus dactylopterus (family Scorpaenidae) presents protamines, whereas Trigla lucerna (family Triglidae) contains histones. Similarly, among the order Perciformes, the species from six families (Percichthyidae, Labridae, Trachinidae, Uranoscopidae, Gempylidae, and Scombridae) have protamines in sperm nuclei and species from two families (Sparidae and Trichiuridae) retain histones and increase the proportion of H1 histone approximately twofold. Two species of Mullus (family Mullidae, order Perciformes) display special proteins with an electrophoretic behaviour corresponding to histone H4 but an amino acid composition more basic.The results indicate that bony fishes have adopted three main alternatives to condense their nuclear sperm chromatin: namely, protamines, histones, and histone‐like proteins. Moreover, these alternatives do not correspond strictly with phylogeny, favouring the hypothesis that the change “protamine → histone” (or alternatively “histone → protamine”) has occurred independently several times during the evolution of bony fishes. © 1993 Wiley‐Liss, Inc.
Comparison of a fluoresceinated lectin stain with triple staining for evaluating acrosome reactions of dog sperm
Authors: Kawakami Eiichi , Vandevoort Catherine A. , Mahi‐Brown Cherrie A. , Tollner Theodore L. , Overstreet James W. 
Published: June 2005

AbstractIn this study a technique which utilized a fluoresceinated lectin and a fluorescent supravital stain was compared with the conventional triple stain technique for evaluating the viability and acrosomal status of dog sperm. Ten semen samples obtained from 6 normal beagle dogs were evaluated after incubation in vitro with canine capacitation medium. Sperm viability and acrosomal status were assessed at 0, 4, and 7 hours of incubation. Both staining techniques were capable of detecting the increase in spontaneous acrosome reactions which occurs during in vitro capacitation of dog sperm. High positive correlations were observed between the fluorescent stain and the triple stain in the mean values for the percentage of viable sperm and for the percentage of acrosome‐reacted sperm among the viable sperm (r = 0.91, r = 0.97, respectively). However, the fluorescent staining techniques could be carried out much more rapidly than the triple stain technique, and the slides prepared with fluorescent stain were more easily scored because of the higher intensity and greater consistency of staining. These characteristics make the fluoresceinated lectin and the fluorescent supravital stain superior for evaluating acrosome reactions and viability of dog sperm. © 1993 Wiley‐Liss, Inc.
Nightly increase in visual sensitivity correlated with bioluminescent flashing activity in the firefly Photuris versicolor (Coleoptera: Lampyridae)
Authors: Lall Abner B. 
Published: June 2005

AbstractChanges in visual sensitivity as a function of time‐of‐day were studied in the firefly Photuris versicolor. The electroretinograms (ERGs) elicited by photic stimuli of constant intensity and duration were recorded over long periods (18–52 h) while the insect was in constant darkness. The amplitudes of the ERGs elicited by the standard flash were small and remained constant during the daytime hours and increased on average sixfold during the evening hours, reaching a maximum at the onset of darkness and remaining at that high level until the morning hours. The amplitude of the standard response again was reduced in the morning hours to a daytime low value which again persisted until the following evening (Fig. 1). In addition, a series of flashes of varying intensity were administered periodically and logV/logI curves as a function of time‐of‐day were obtained. Compared to the daytime logV/logI curves, the nighttime curves were shifted about 4 log units towards the left on the intensity axis (Fig. 2). This period of high visual sensitivity was correlated with the species' flashing activity period, which occurs during the night hours (Fig. 1). © 1993 Wiley‐Liss, Inc.
Presence of insulin‐like growth factor binding protein (IGF‐BP) in rainbow trout (Oncorhynchus mykiss) serum
Authors: Niu P.‐D. , Le Bail P.‐Y. 
Published: June 2005

AbstractRecombinant human IGF‐I (hIGF‐I) binding to rainbow trout serum fractions was studied in vitro. Binding protein preparations, from human and trout serum (hBP and tBP), which were obtained using size exclusion chromatography (AcA 54) under acid conditions, were used to characterize IGF binding protein. Mammalian protein binding assay, using hIGF‐I as labeled hormone, was optimized (pH, Tris concentration, bound‐free 125I‐hIGF‐I separation conditions by charcoal) for trout serum. The association kinetics (T = 4°C) of specific binding presented a plateau from 20–30 h, and nonspecific binding remained stable for the same time. Percentage of 125I‐hIGF‐I which was able to bind to tBP was at least 55%. In the same incubation conditions, hIGF‐I binding to trout BP had a higher affinity (Ka = 2.8 1010 M–1) than those obtained with human BP preparation (Ka = 0.17 1010 M–1) which contains four molecular forms of BPs. The binding was saturable but its capacity was fourfold lower in trout (Bmax = 410 ng/ml of serum) than in human (Bmax = 1868 ng/ml) serum. Binding to trout BP is very specific for human IGF‐I and for trout IGF serum extract. hIGF‐II crossreacts partially but no binding was observed with porcine insulin. When trout serum was chromatographed on an analytic AcA 54 column (1 × 100 cm), the maximum hIGF‐I activity was found in a peak which corresponded to 55 kDa. Two other peaks (34 and 23 kDa) also bound hIGF‐I, but with a much lower activity. In Western‐ligand‐blot from SDS‐PAGE, binding of 125I‐hIGF‐I to trout serum presented a major band (MW = 41.5 kDa) similar to the biggest form of IGF‐BP‐3 from human serum. These results suggest that IGF binding protein(s) exists in trout serum but the majority of IGF binding activity is carried only by one form (41.5 kDa), in contrast to mammals which have four forms of BP with a similar magnitude of serum concentration. © 1993 Wiley‐Liss, Inc.
Effect of T3 or T4 challenge on inner‐ and outer‐ring deiodination of T3 and T4 in the liver, kidney, and gill of rainbow trout, Oncorhynchus mykiss
Authors: MacLatchy Deborah L. , Eales J. G. 
Published: June 2005

AbstractThe effects of feeding 3,5,3′‐triiodo‐L‐thyronine (T3)‐ and L‐thyroxine (T4)‐supplemented diets for 3 days on the plasma T3 and T4 concentrations and on the plasma outerring (5′D) and inner‐ring (5D) deiodination of T4 and T3 were studied in vitro for the liver, gill, and kidney of rainbow trout (Oncorhynchus mykiss) at 12°C. Trout were sampled 24 hr after their last meal. T3 treatment increased plasma T3 but did not alter plasma T4. T4 treatment did not alter plasma T3 or T4. In untreated trout, T45′D activity to form T3 occurred in all 3 tissues; T45D activity to form 3,3′,5′‐T3 (rT3) was not significant, T35D activity to form 3,3′‐T2 (diiodo‐L‐thyronine) was low, and T35′D activity to form 3,5‐T2 was barely detectable. A low‐Km T45′D (T4 concentration = 0.65 nM) was confirmed in liver and gill, and a high‐Km T45′D (T4 concentration = 12 nM) was confirmed in liver and kidney. For liver, T3 feeding depressed both low‐Km and high‐Km T45′D isozymes, but induced T45D and T35D; T4 feeding depressed only the high‐Km T45′D and increased T35′D slightly. For gill, T3 feeding depressed the low‐Km T45′D and induced T45D; T4 feeding increased T35′D. For kidney, T3 feeding depressed the high‐Km T45′d and induced T35′D; T4 feeding depressed the high‐Km T45′D and increased T35′D. We conclude that in response to either a T3 or a T4 challenge, trout tissues employ several T3 homeostatic mechanisms. Responses to a T3 challenge included (1) depression of both low‐Km and high‐Km T45′D activities to decrease production of T3, (2) elevation of T45D activity to direct T4 substrate to rT3, and (3) elevation of T35D activity to degrade T3 to 3,3′‐T2. In contrast, responses to a 4‐fold greater dietary T4 challenge were restricted primarily to depression of high‐Km T45′D activity in the liver and kidney. © 1993 Wiley‐Liss, Inc.
In vitro exposure of frog (Rana pipiens) pituitaries to gonadotropin‐releasing hormone results in a persistent stimulation of gonadotropin biosynthesis
Authors: Stamper Debra L. , Licht Paul 
Published: June 2005

AbstractTo further investigate the action of gonadotropin‐releasing hormone (GnRH) on gonadotropin (Gth) secretion and synthesis, pituitaries from frogs, Rana pipiens, were incubated in the presence or absence of 100 ng/ml GnRH for 12 h. GnRH was then removed from the medium and glands were labeled with 35S‐methionine either 12, 24, or 36 h after the conclusion of GnRH exposure. Immunoassayable LH and FSH (iLH and iFSH; both labeled and nonlabeled hormone) were determined by separate radioimmunoassays. Newly synthesized (radiolabeled) Gth was quantified by immunoprecipitation. When GnRH was present in the medium, it stimulated the secretion of both iLH and iFSH (compared to unexposed glands). Following withdrawal of the secretagogue, iLH and iFSH secretion diminished until they returned to control levels (within ca. 12 h). Previous exposure to GnRH enhanced the biosynthesis of Gth; this elevation was detectable up to 36 h after removal of the secretagogue. The magnitude of the elevation in Gth synthesis did not diminish with time, as secretion had, but remained constant. Gth synthesis was comparable in glands that had been exposed to GnRH 12 h and those exposed to the secretagogue 36 h prior. Thus, the GnRH‐induced elevation in Gth secretion and synthesis can be dissociated; the elevation in synthesis is more chronic than the elevation in secretion. © 1993 Wiley‐Liss, Inc.
Dual origin of yolk nuclei in the lesser spotted dogfish, Scyliorhinus canicula (Chondrichthyes)
Authors: Lechenault Henri , Mellinger Jean 
Published: June 2005

AbstractUsing plastic embedding techniques and semithin sections in order to overcome the difficulties encountered in the sectioning of yolky eggs, we made a histological study of the developing blastodisc and early embryo of the oviparous dogfish Scyliorhinus canicula (L.) (Pisces: Chondrichthyes) from Roscoff (Brittany, France). According to our observations, several conclusions based on classical studies on elasmobranch development have to be revised as follows: (i) Cleavage of the germinative disc into blastomeres lags considerably behind the mitotic activity of diploid nuclei derived from amphimixy. As a result, the number of surface blastomeres does not correspond in any way to the actual number of nuclei, even at the start of segmentation. Thus, segmentation is primarily syncytial. (ii) The first set of yolk nuclei corresponded to the deepest nuclei that remained beneath the segmentation cavity after complete cellularization of the blastodisc. They became polyploid, some of them degenerated, and the others multiplied while remaining close to the extraembryonic endoderm during epiboly. (iii) A second set of yolk nuclei was derived from the embryonic endoderm along its boundary with the extraembryonic endoderm. Endoderm cells escaped into the yolk layer nearby. They then give off free nuclei, which also became very large and finally were indistinguishable from the first set. (iv) No yolk nuclei were derived from supernumerary sperm nuclei, even when the latter were able to divide several times in synchrony. Nuclei from this haploid lineage were always smaller than those in the first set, and they were finally located in the deepest layer of the germinative disc, where they degenerated. It is concluded that this chondrichthyan fish generates its yolk syncytium in a very different way from teleosts, in which all yolk nuclei are derived from the blastodisc. © 1993 Wiley‐Liss, Inc.
Physiology and central projection of auditory receptor cells in the prothoracic ganglion of three closely related species of bushcrickets (Tettigoniidae, insecta)
Authors: Ahi Janak , Kalmring Klaus , Ebendt Rüttger , Hellweg Judith 
Published: June 2005

AbstractA comparative study was made of the projection patterns of functionally and morphologically identified auditory receptor cells of the complex tibial organ in the forelegs of three closely related Decticine species. A combined recording and staining technique was used, with subsequent histological examination and morphometric measurements. Adult males and females of the species Psorodonotus illyricus, Decticus albifrons, and Decticus verrucivorus, were chosen for this investigation. No species‐specific differences were found in the projection patterns of receptor cells that belonged to the same or similar functional classes in the three species. The cells also occupied the same target areas within the neuropile. A significant overlapping of the projections of the different receptor cells within the neuropile of the anterior ring tract (aRT) was revealed, in particular of those cells that were tuned to characteristic frequencies within similar frequency bands. © 1993 Wiley‐Liss, Inc.
Recovery of viability in triploid hybrids between Japanese and European water frogs, and their reproductive capacity
Authors: Ohtani Hiromi , Kondo Yasuyuki 
Published: June 2005

AbstractDiploid and triploid hybrids, consisting of the various combinations of chromosome set and cytoplasm between Rana nigromaculata and Rana lessonae, were generated in order to study their viability and reproductive capacity. Reciprocal diploid hybrids and allotriploids, which had two lessonae genomes and one nigromaculata genome in nigromaculata cytoplasm, all died without closing their neural folds. Allotriploids, which had two nigromaculata genomes and one lessonae genome in nigromaculata cytoplasm, all grew into healthy mature males in 12.4% (21 frogs) of zygotes. Following the elimination of lessonae chromosomes, ten of these males produced many spermatozoa containing a haploid set of nigromaculata chromosomes. Other allotriploids, which had either one nigromaculata genome and two lessonae genomes or two nigromaculata genomes and one lessonae genome in lessonae cytoplasm, exhibited slightly improved viability. © 1993 Wiley‐Liss, Inc.
Stimulation of oxidative metabolism by thyroid hormones in propranolol/alloxan‐treated bony fish, Anabas testudineus (Bloch)
Authors: Peter M. C. Subash , Oommen Oommen V. 
Published: June 2005

AbstractThe specific activities of oxidative enzymes, in response to 3,5,3′ triiodo‐L‐thyronine (T3) and L‐thyroxine (T4) administration, were assayed in the teleost, Anabas testudineus pretreated with the beta adrenergic antagonist, propranolol, and the beta islet cell cytotoxin, alloxan. Administration of propranolol or alloxan decreased the activity of cytochrome oxidase, succinate dehydrogenase (SDH), mitochondrial adenosine triphosphatase (Mg2+ ATPase), lactate dehydrogenase (LDH), and cytosolic malate dehydrogenase (cMDH) and did not change that of α‐glycerophosphate dehydrogenase (α‐GPDH) and glucose‐6‐phosphate dehydrogenase (G‐6‐PDH). Propranolol treatment decreased and alloxan administration did not change the mitochondrial MDH (mMDH) activity. A single injection of T3 or T4 significantly stimulated cytochrome oxidase and oc‐GPDH activities, and decreased Mg2+ ATPase, cMDH, and mMDH activities but did not affect SDH, G‐6‐PDH, or LDH. The activity of cytochrome oxidase, oc‐GPDH, SDH, and Mg2+ ATPase was increased by T4 or T3 injection into propranolol or alloxan‐treated fish. The data suggest that in teleosts, the stimulatory effect of thyroid hormones on oxidative metabolism is not mediated through the potentiation of adrenaline or insulin action. © 1993 Wiley‐Liss, Inc.
Stimulatory effect of fractions of brain homogenate on protein synthesis in ovaries of Eisenia fetida Sav. In Vitro (Oligochaeta, Annelida)
Authors: Lattaud C. , Marcel R. 
Published: June 2005

AbstractIn Eisenia fetida, during the period of genital activity, the synthesis of androgen by testicular tissues is under the control of a neurohormone elaborated by cerebral ganglia (CG). These ganglia also have a trophic effect on ovarian protein synthesis. Present results confirm that incorporation in vitro of [3H]‐leucine by ovaries is stimulated by a cerebral neurohormone. Furthermore, fractions of brain homogenate, obtained by gel filtration on Sephadex G 25, have the same action on ovaries in organ culture as CG. Two specific fractions (fractions 3 and 4) stimulate protein synthesis in the ovary. In the ovarian oocytes, the rate of vitellogenesis is low, since in cultured isolated ovaries the amount of radioactive precursor incorporated is only 0.06% of the amount added and this percentage remains low in the ovaries cultured with fractions 3 and 4 (0.15% and 0.21%, respectively) or with CG (0.24%). Further research is necessary to obtain and characterize the biologically active material. © 1993 Wiley‐Liss, Inc.
Metamorphosis‐dependent recognition of larval skin as non‐self by inbred adult frogs (Xenopus laevis)
Authors: Izutsu Yumi , Yoshizato Katsutoshi 
Published: June 2005

AbstractLarval cells in tissues of the anuran tadpole are replaced by adult cells in the corresponding tissue of the frog during metamorphosis. As an extreme example of such replacement, tissues of the tail, which have no counterpart in the adult, are completely eliminated during metamorphosis. We postulated that some immunological recognition mechanism might be involved in this specific elimination of the tail tissue. Our working hypothesis was tested by applying the skin transplantation technique to individuals of the inbred J strain of Xenopus laevis, which accept homografts. We demonstrated that young adults reject skin grafts from larvae. This rejection was immunological in nature because the secondary response of rejection was observed. There was a clear difference in graft rejection between grafts from the tail and those from the body. Grafts of tail skin were rejected irrespective of the metamorphic stages of donors. By contrast, grafts of body skin became acceptable as donors metamorphosed. The mean survival time of the larval skin was much longer than that of major histocompatibility complex (MHC)‐disparate skin grafts reported by other investigators, suggesting that the rejection described in the present study is due to disparity in minor histocompatible (minor‐H) antigens. We propose the involvement of the immunological recognition mechanism in the process of specific detection and elimination of larval cells in the tail. © 1993 Wiley‐Liss, Inc.
Physiological response of Zebu and Taurine oxen to draught work
Authors: Zanzinger Johannes , Becker Klaus , Rometsch Martin 
Published: June 2005

AbstractFour Zebu and four Simmental oxen were submitted to continuous and to graded draught work. Venous blood samples were taken before, during, and after exercise at intervals of 2–5 min. Anaerobic threshold was reached at a draught power of 1.6 ± 0.06 kW for Zebu and 0.7 ± 0.07 kW for Simmental. Corresponding plasma lactate concentrations were 1.7 ± 0.2 mmol/liter and 1.6 ± 0.3 mmol/liter, respectively. Partial pressure of oxygen (pvO2), carbon dioxide (pvCO2), and plasma free fatty acids (FFA) during and after work differed between breeds (P ∼ .001) and individuals (P ∼ .05). After work, an up to 8‐fold increase in FFA was found. Highest plasma lactate concentrations during continuous maximal draught were 3.75 ± 1.76 (Zebu) and 6.01 ± 0.88 mmol/liter (Simmental). Acid‐base‐state during and after exhaustive work remained stable. Heart rate in both breeds did not exceed 190 min−1. It is concluded that 1) even during heavy draught work, anaerobic energy formation plays a minor role for cattle, 2) fatigue in working oxen may be related to cardiovascular limitations, and 3) the physical fitness of European beef‐breed oxen is lower compared to multipurpose African Zebu oxen. © 1993 Wiley‐Liss, Inc.
Comparison of hemolymph lipoproteins from four species of crustacea
Authors: Komatsu Masaharu , Ando Seiichi , Teshima Shin‐Ichi 
Published: June 2005

AbstractTwo different lipoproteins, lipoprotein I and very high density lipoprotein (VHDL), were isolated from the male hemolymphs of freshwater prawn, mitten crab, and striped stone crab by a different density gradient ultracentrifugation. Lipoprotein II as well as lipoprotein I and VHDL was further found in the female hemolymphs of these crustacea. Lipoprotein II seemed to be a vitellogenin and spawned kuruma prawn without eggs lacked lipoprotein II in their hemolymph. The densities of lipoprotein I varied between 1.12 and 1.18 g/ml reflecting the difference of protein‐lipid ratio. In contrast lipoprotein II and VHDL had approximately constant densities of 1.19—1.21 g/ml and 1.26—1.27 g/ml, respectively. Lipoprotein I, lipoprotein II, and VHDL isolated from the crustacean hemolymph contained phospholipid as a predominant lipid component. Crustacean lipoprotein was divided into the freshwater type and the seawater type. Freshwater prawn and mitten crab classified into the freshwater type tended to have high protein concentrations in lipoprotein I and VHDL. In contrast both lipoprotein I and VHDL protein concentrations from kuruma prawn and striped stone crab, which were classified into the seawater type, were much lower than those from the freshwater type. Lipoprotein I from freshwater prawn and mitten crab had two major apolipoproteins with apparent molecular weights of 230,000 and 100,000, and 340,000 and 100,000, respectively, while lipoprotein I from kuruma prawn and striped stone crab consisted of three major apolipoproteins (molecular weights 180,000, 100,000, and 80,000). VHDL found for the first time in crustacea probably plays an important role in lipid transfer reaction between lipoproteins. © 1993 Wiley‐Liss, Inc.
Effects of insulin on the glucose uptake by the thyroid gland of the turtle Chrysemys dorbigni acclimated to different temperatures
Authors: Machado Vera L. A. , Marques Maria 
Published: June 2005

AbstractInsulin stimulation of the glucose uptake by the thyroid gland of the turtle (Chrysemys dorbigni) has been previously reported. The aim of the present study was to examine the influence of different temperatures (6, 25, or 36°C) on this effect. Insulin‐stimulated glucose uptake was evident when turtles were acclimated for 15 days at 25° or 36°C, and their glands studied at the respective temperatures. In glands from turtles acclimated at 6°C, this effect was only seen when the preincubation and incubation time was extended from 60 to 300 min. The findings show that in this ectotherm species (1) the insulin effect is temperature dependent, and (2) can be expressed at very low temperature. © 1993 Wiley‐Liss, Inc.