bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of plasma membrane Na+/H+ exchange in eel (Anguilla anguilla) intestinal epithelial cells
Authors: Vilella S. , Zonno V. , Lapadula M. , Verri T. , Storelli C.
Published: June 2005

The ability of eel intestinal epithelial cells to recover from an acute acid load was analysed using the fluorescent dye 2′, 7′‐bis‐carboxy‐ethyl‐5, 6‐carboxyfluorescein (BCECF) and cell suspensions. Under these experimental conditions (bicarbonate‐free solutions) the resting pHi in cells prepared from sea‐water (7.52 ± 0.031) and fresh‐water (7.50 ± 0.094) adapted animals proved to be similar. The recovery rate (following an acid load) increases by increasing the Na ion concentration in the extracellular medium. This pHi recovery is competitively inhibited by the specific inhibitor dimethylamiloride (DMA) with a low Ki in sea‐ (1.2 μM) as well as in fresh‐water (1.3 μM) adapted animals, indicating the presence of a specific Na/H exchange activity in these cells. Using basolateral membrane vesicles it could be demonstrated that this activity is located on the basolateral side of the enterocyte membrane. The kinetic parameters (Kapp and Jmax) of this exchanger are similar in fresh‐water and sea‐water adapted animals suggesting that no salinity adaptation occurs, thus excluding the involvement of the antiporter in the osmoregulatory processes. These results are in agreement with the presence in the plasma membrane of the eel enterocytes of a Na/H‐l (housekeeper) form of the antiporter. © 1995 Wiley‐Liss, Inc.
Model for cooperative control of positional information in Drosophila by bicoid and maternal hunchback
Authors: Reinitz John , Mjolsness Eric , Sharp David H.
Published: June 2005

The blastoderm of the fruit fly Drosophila melanogaster is unusually well suited for analysis of fundamental questions in animal development. One such question is how genes specify the positional information which determines the developmental pathways (fate) of cells at appropriate spatial locations. In this paper we propose a dynamical model of gene regulation which explicitly describes how positional information is used in the blastoderm. The model is applied to analyze important experimental findings on the dependence of cell fate on the concentration of the Bicoid morphogen. The model shows that positional information in the presumptive middle body is cooperatively determined by maternal products of the bicoid and hunchback genes. © 1995 Wiley‐Liss, Inc.
Activation of murine oocytes with Ca2+ ionophore and cycloheximide
Authors: Hagemann L. J. , Hillery‐Weinhold F. L. , Rutledge M. L. Leibfried , First N. L.
Published: June 2005

A Ca2+ ionophore (A23187, 3 μM) and inhibitor of protein synthesis (cycloheximide, 10 μg/ml) were used sequentially as a unique method for activating mouse oocytes in vitro. Brief exposure of oocytes to A23187 followed by 6 hr in cycloheximide resulted in a higher activation rate (93.8%) compared to A23187 or cycloheximide alone (37.7% and 36.5%, respectively) or the two reagents in reverse order (29.8%). The parthenogenones consistently contained a single pronucleus and second polar body, and showed a high degree of developmental potential, as assessed by transfer to recipient females or addition of a male pronucleus followed by transfer to recipients. This method is a useful way of obtaining large numbers of activated haploid mammalian oocytes for further developmental studies. © 1995 Wiley‐Liss, Inc.
Immunohistochemical evidence that gonads and gonad‐associated tissues are sites for enrichment with immunoglobulin‐containing cells in adult chickens
Authors: Zettergren Leslie D.
Published: June 2005

Immunohistochemical staining of tissue sections prepared from gonads and gonad‐associated tissues obtained from adult chickens was performed in order to assess the possibility that these tissues may be sites of enrichment with IgM‐containing cells in various B lineages. Evidence is presented which suggests that IgM‐containing B lineage cells are present in 1) the ovarian stroma and subcapsular areas of the ovary and 2) the interstitium and subcapsular areas of the epididymis of the testes. These represent new sites reported for B lineage cells in adult chickens. Some questions relevant to the physiologic, ontogenetic, and phylogenetic implications of these observations relative to vertebrate hematolymphopoietic processes are included. © 1995 Wiley‐Liss, Inc.
Interdependence of corticosterone and thyroid hormones in larval toads (Bufo boreas). I. Thyroid hormone‐dependent and independent effects of corticosterone on growth and development
Authors: Hayes Tyrone B.
Published: June 2005

In a previous study (Hayes et al. [1993] J. Exp. Zool., 266: 206–215), we demonstrated that exogenous corticosterone (B) inhibited growth, and had varied effects on development and metamorphosis in the toad(Bufo boreas). The current study determined the relation between the action (length and height), rear leg growth and differentiation, and foreleg emergence (FLE). Thiourea (Thio; a goitrogen) and metyrapone (MTP; a glucocorticoid synthesis inhibitor) were used to determine the role of endogenous hormones in growth and development. These inhibitors were also used in various combinations with the thyroid hormones, thyroxine (T4) and triiodothyronine (T3), to determine the extent to which B's actions depend on the thyroid hormones. B was ineffective at inducing tail reduction (length and height) in the presence of Thio, but B enhanced the effects of both thyroid hormones, suggesting that the action of B on the tail were dependent on thyroid hormones. B inhibited body growth even in the presence of Thio, but did not enhance thyroid hormone's inhibition of growth. B alone stimulated foreleg emergence (FLE) and enhanced thyroid hormone's activity on FLE when B and the thyroid hormones were given in combination, but did not induce FLE in the presence of Thio. B stimulated rear leg development, but not in the presence of Thio, suggesting that this effect was due to interactions with thyroid hormones. Furthermore, MTP antagonized the stimulatory effect of T4 on rear leg development, suggesting that endogenous B also interacted with exogenous thyroid hormones. While the thyroid hormones stimulated rear leg growth, B inhibited rear leg growth and antagonized the effects of the thyroid hormones when the hormones were given together. This study demonstrated that while some of the effects of B (such as the stimulation of tail resorption) depend on endogenous thyroid hormones, other effects (such as the inhibition of rear leg growth) are antagonistic to the thyroid hormones. © 1995 Wiley‐Liss, Inc.
Interdependence of corticosterone and thyroid hormones in toad larvae (Bufo boreas). II. Regulation of corticosterone and thyroid hormones
Authors: Hayes Tyrone B. , Wu Tzu Hao
Published: June 2005

Typically, the role of corticosterone (B) in metamorphosis is considered secondary to that of thyroid hormone, with B having only enhancing effects. In the current study, we demonstrate that the relationship between the thyroid hormones and B is much more complex and that thyroxine (T4) may depend on B for some of its functions. Tadpoles of the western toad (Bufo boreas) were treated with various combinations of corticosterone (B), thyroxine (T4), triiodothyronine (T3), a goitrogen (thiourea; Thio), and a corticoid synthesis inhibitor (metyrapone; MTP). Hormones were extracted from individual tadpoles and whole‐body hormone levels determined by radioimmunoassay. B‐treatment decreased the ratio of T4 to T3, suggesting that B increased the conversion of endogenous T4 to T3. In addition, B‐treatment in combination with T4 resulted in high whole body‐levels of T3. B also caused a decrease in whole body‐thyroid hormone levels (T4 and T3), suggesting negative feedback on the hypothalamo‐pituitary‐thyroid axis and T3 had a similar effect, decreasing whole body‐T4 levels. T4‐treatment, but not T3, increased whole body‐B levels and MTP‐treatment in combination with T4 prevented the stimulatory effect of T4 on B production. MTP‐treatment alone blocked all steroid metabolism of [3H]progesterone by the interrenal in vitro, and lowered whole body‐B levels three‐fold in vivo. Thio‐treatment reduced thyroid hormone levels and also resulted in decreased B. Finally, we suggest that these results demonstrate a system in which T4 may regulate its own potency: increasing T4 stimulates B production, which increases the conversion of T4 to its more active form T3. Rising T3 levels then cause a decrease in T4, removing the stimulatory effect of T4 on B. These interactions between the thyroid hormones and B help clarify the mechanisms underlying the morphological effects of these hormones described in the previous study. © 1995 Wiley‐Liss, Inc.
Role of steroids in antler growth of red deer stags
Authors: Suttie J. M. , Fennessy P. F. , Lapwood K. R. , Corson I. D.
Published: June 2005

A series of six studies were carried out in red deer stages to test hypotheses concerning the importance of steroid control of velvet antler growth and to investigate mechanisms by which these hormones exert their effects. Medroxyprogesterone acetate (MPA) an LH inhibitor administered to stags during hard antler caused premature antler casting, reduced subsequent antler weight and caused a reduction in the LH and testosterone responses to GnRH. In two separate studies blockade of testosterone receptors with cyproterone acetate (CPA) administered to stags, either during early velvet antler growth or during the hard antler stage, significantly reduced LH and testosterone responses to GnRH. In both studies antler length, but not weight, was increased by CPA treatment. In another study testosterone implants were used to pervent the gradual decline in plasma testosterone levels normally observed during winter. Implants were removed 3 weeks before the anticipated date of antler casting. The implants significantly increased plasma testosterone levels and subsequent antler growth (expresses as a proportional increase compared with the previous year) compared with untreated controls. To determine whether the annual cycle of plasma testosterone response following GnRH stimulation was due simply to a lack of LH stimulation, ovine LH was injected on six occasions at defined stages of the antler cycle to red deer stags and the testosterone response measured. The testosterone responses were low at antler casting and during velvet antler growth compared with antler cleaning and peak rut. It appears low level of testosterone levels are due, in part, to a loss of responsiveness by the testes to LH as well as a low level of secretion of LH during the antler growing season. Finally synthetic ACTH was injected at the same defined stages of antler growth as in the previous study to determine whether cortisol and adrenal androgen production altered with the stage of the antler cycle. No significant differences were found in the dehydroepiandrosterone (DHEA) response, but cortisol responses were higher from late velvet antler growth to peak rut, compared with the times of antler casting and early velvet growth. Overall it was concluded that velvet antler growth can occur without testosterone stimulation during the period of velvet growth, but the data reinforce the concept that the timing of antler growth is linked to the annual cycle of testosterone. © 1995 Wiley‐Liss, Inc.
Lysophosphatidylcholine treatment allows interspecies fertilization of hamster oocytes with zona pellucida by human spermatozoa
Authors: Riffo Marta , Parraga Mario
Published: June 2005

The study of interspecific gamete interactions has been improved by the use of in vitro fertilization techniques. Zona pellucida is at the cellular level the main barrier to cross‐fertilization. Moreover, there are several cases in which the heterologous spermatozoa fail to enter the cytoplasm of zona‐free oocytes, emphasizing the notion that another important barrier exists to cross‐fertilization at the egg plasma membrane level. We report here a simple method to fertilize hamster oocytes with zona pellucida by human spermatozoa. We used lysophosphatidylcholine (LPC), a fusogenic agent, to treat spermatozoa, spermatozoa and zona‐intact oocytes, or zona‐intact oocytes alone. This molecule allows the penetration of hamster oocytes zona by human spermatozoa. Our results suggest that LPC modifies the zona pellucida of oocytes and the plasma membrane of both gametes in vitro, favouring sperm penetration through the zona pellucida and gamete fusion. © 1995 Wiley‐Liss, Inc.
Effects of acclimation salinity and in vitro medium osmotic pressure on the incorporation of3H‐leucine into the two prolactins of the tilapia, Oreochromis mossambicus
Authors: Yoshikawa‐Ebesu Joanne S. M. , Borski Russell J. , Richman N. Harold , Grau E. Gordon
Published: June 2005

The control of synthesis of the two prolactins (tPRL188 and tPRL177) in the anterior‐most portion of the pituitary, the rostral pars distalis (RPD), was investigated in freshwater (FW)‐ and seawater (SW)‐ acclimated tilapia. Individual RPD of FW and SW male tilapia were incubated in either hyposmotic or hyperosmotic medium containing3H‐leucine for various intervals, up to 360 min. The total quantity of the two tPRLs in media and RPD was assessed by gel electrophoresis and scanning densitometry of the stained bands. Synthesis was characterized as the uptake of3H‐leucine into the tPRL molecules. Results showed greater synthesis and release of both3H‐tPRLs in the RPD from FW tilapia than in those from SW‐ acclimated tilapia. The in vitro synthesis of both prolactins tPRLl88 and tPRL177 in RPD of FW tilapia and tPRLl77 in RPD of SW fish was also augmented by exposure to hyposmotic medium. The ratio of the appearance of newly synthesized3H‐ tPRLl88:3H‐tPRL177was approximately 1.3 in FW tilapia RPD and approximately 0.5 in SW tilapia RPD. The delay between effect of osmotic pressure on tPRL release and its effect on tPRL synthesis suggests that the rapid effect of osmotic pressure upon PRL release is at least partially independent of its effect upon tPRL synthesis. Moreover, the altered ratios of tPRL188 and tPRL177 observed in our studies suggest that the synthesis rates of the two tPRLs are differentially sensitive to environmental salinity. © 1995 Wiley‐Liss, Inc.
Incilaria mucus agglutinated human erythrocytes
Authors: Furuta Emiko , Takagi Takashi , Yamaguchi Keiichiro , Shimozawa Atsumi
Published: June 2005

The body surface mucus from the land slug, Incilaria fruhstorferi, not only opsonized sheep red blood cells (SRBC) and agglutinated human types A and B erythrocytes (HRBC) but also caused hemolysis of B type HRBC 12 h after agglutination. The mucus‐induced hemagglutination was specifically inhibited by a low concentration of N‐acetyl D‐galactosamine (GaINAc), and all of this activity was completely inactivated by heating at 56°C for 30 min. SDS‐polyacrylamide gel electrophoresis of water soluble fraction of the mucus showed that this fraction contained several proteins, the molecular mass of the main band being 35 KD. © 1995 Wiley‐Liss, Inc.
Removal of embryo‐toxic ammonium from the culture medium by in situ enzymatic conversion to glutamate
Authors: Lane Michelle , Gardner David K.
Published: June 2005

An enzymatic method for removing embryo‐toxic ammonium from culture medium has been developed. Ammonium, produced by both embryo metabolism and spontaneous breakdown of amino acids at 37°C, is transaminated by glutamate dehydrogenase to nontoxic glutamate. Initially, the individual components of the transamination reaction were titrated against mouse embryo development in vitro to determine embryo‐safe levels. ADP, an allosteric activator of glutamate dehydrogenase, was found to inhibit embryo development and was therefore omitted from the final formulation (α‐ketoglutarate, 0.44 mM; glutamate dehydrogenase, 0.375 U; NADH, 0.12 mM). It was found that 0.30 mM ammonium could be removed from the culture medium in situ in 3 h. In situ removal of ammonium significantly increases both blastocyst cell number, implantation, fetal development, and fetal weight after transfer. Removal of ammonium by the conventional method of renewing the culture medium also increased blastocyst cell number but did not affect postimplantation development. In conclusion, it is possible to alleviate the toxic effects of ammonium in vitro on pre‐ and postimplantation mouse embryo development by its transamination in situ. Thereby facilitating the continual exposure to embryo‐derived factor(s) which stimulates both pre‐ and postimplantation development. © 1995 Wiley‐Liss, Inc.
Embryonic growth and maternal nutrient sources in goodeid fishes (Teleostei: Cyprinodontiformes)
Authors: Hollenberg Frank , Wourms J. P.
Published: June 2005

Most species of the viviparous teleost family Goodeidae exhibit an unusual placental relationship. Embryos lay free within the single, hollow ovary where they are bathed by the ovarian fluid. Nutrients are absorbed from the fluid through distinctive perianal processes called trophotaeniae. Trophotaeniae represent the embryonic component of the placenta and may be functionally divided into protein endocytosing and nonendocytosing types. The maternal component of the placenta is the internal ovarian epithelium (IOE). Since embryos undergo dry weight increases ranging from 68‐ to 387‐fold compared to the dry weight of mature ova, there must be substantial nutrient transfer from the maternal organism during gestation. Transmission electron microscopy of the IOE of gravid females of three goodeid species fails to reveal evidence of significant synthetic activity by the IOE, although occasional budding of parts of IOE cells occur, and the IOE of one species, G. atripinnis, contains substantial amounts of lipid. Electrophoretic comparison of nongravid females of two species establishes that the protein pattern of the ovarian fluid is similar to that of the female blood serum. In gravid females whose embryos bear protein‐endocytosing trophotaeniae, protein is undetectable in the ovarian fluid during mid‐ and late gestation, suggesting efficient protein absorption by the trophotaeniae. In gravid females whose embryos bear nonendocytosing trophotaeniae, serum proteins are present in the ovarian fluid at midgestation, but are reduced to only a trace at late gestation suggesting possible imbibition by the embryos. © 1995 Wiley‐Liss, Inc.
Lipovitellin and lipid droplet accumulation in oocytes during ovarian maturation in the blue crab, Callinectes sapidus
Authors: Lee Richard F. , Walker Anna
Published: June 2005

Blue crab ovaries rapidly increased in weight during the 30 days after the terminal molt into adulthood. Oocytes isolated from ovaries during this period increased in diameter from 40 to 201 μm. The concentrations of lipovitellin, a high density lipoprotein found in oocytes, were determined by a competitive ELISA procedure using a monoclonal antibody against one of the lipovitellin peptides. Lipovitellin and lipid droplets were minor components in the immature ovaries and oocytes but increased in concentration to become the major components of the mature ovaries and oocytes. In mature oocytes (201 μm diameter) lipovitellin concentrations accounted for 35 and 95% of the total oocyte protein and soluble oocyte protein, respectively. In mature oocytes the total lipid, lipovitellin lipid, and lipid droplet concentrations were 510, 240, and 140 ng/oocyte, respectively. Sections of ovaries and hepatopancreas at different stages of maturation were probed with the anti‐lipovitellin antibody. In small immature oocytes, where no yolk was present, the immunoreactivity was confined to perinuclear yolk complexes. The immunoreactivity of more mature oocytes was associated with globular structures in the cytoplasm. Neither ovarian follicle cells nor hepatopancreas cells showed immunoreactivity. Our results suggest that in blue crabs the lipovitellin components are primarily synthesized in the developing oocytes with perinuclear yolk complexes playing an important role in the formation of lipovitellin‐rich yolk granules. Scattered collections of presumed phagocytic hemocytes contained immunoreactive granular material in their cytoplasm. We suggest that these hemocytes remove debris from oocytes which fail to reach maturation and carry this debris to the hepatopancreas. © 1995 Wiley‐Liss, Inc.
In vitro hepatocyte metabolism of alanine and glucose and the response to insulin in fed and fasted rainbow trout
Authors: Pereira C. , Vijayan M. M. , Moon T. W.
Published: June 2005

Rainbow trout (Oncorhynchus mykiss) fasted for 4 months had lower plasma glucose concentration and hepatocyte glycogen content than the fed fish. Gluconeogenesis from alanine in the fasted fish was not significantly different from that of the fed fish, Whereas both alanine glyconeogenesis and oxidation increased with fasting by 400% and 300%, respectively. Glyconeogenesis from glucose was not significantly different with fasting, whereas glucose oxidation decreased significantly with fasting. The presence of glucose (10 mM) in the medium did not modify alanine glyconeogenesis or gluconeogenesis in either the fed or the fasted groups. However, glucose did increase alanine oxidation in the fed group but not in the fasted group, this response being further stimulated in the presence of insulin. Alanine (2 mM) in the medium had no effect on glyconeogenesis from glucose in either fed or fasted trout hepatocytes. Insulin significantly decreased glucose oxidation in the fed fish, whereas the insulin effect on glucose oxidation in the fasted fish occurred only in the presence of alanine. The results indicate that nutritional state affects hepatocyte responsiveness to substrate utilization and insulin stimulation in trout. Specifically, the hepatocyte potential for glyconeogenesis is enhanced in the fasted fish, although this increased glycogen production is not due to an increased glucose utilization. © 1995 Wiley‐Liss, Inc.
Bh(black at hatch) gene appears to cause whole‐body hemorrhage in homozygous embryos of Japanese quail (Coturnix coturnix japonica)
Authors: Kubota Yukihiko , Nakamura Akira , Ito Michio , Shiojiri Nobuyoshi
Published: June 2005

Genotypes of early embryos obtained from mating Bh/+ quail were determined by chorio‐allantoic membrane grafting of their thigh skin, and the development of The Bh homozygous embryos was examined histologically. The Bh homozygous embryos died at an early stage of development (after 7 to 10 days of incubation) with a very high incidence of whole‐body hemorrhage (approximately 100%), but malformation of neural tubes was not always accompanied by Bh homozygosity. Degeneration of the liver was more frequently observed in homozygous embryos than in wild‐type and heterozygous embryos. The results suggest that the Bh gene causes whole‐body hemorrhage and subsequent death of homozygous embryos. In addition, our data indicate that Bh homozygote would develop brown feathers on theirskin if they were able to survive. © 1995 Wiley‐Liss, Inc.
17α, 20α‐dihydroxy‐4‐pregnen‐3‐one, not its 20β isomer, is produced from 17α‐hydroxyprogesterone by spermatozoa of secondary male groupers (Epinephelus tauvina) derived from females implanted with 17α‐methyltestosterone
Authors: Tan A. M. C. , Lee S. T. L. , Kime D. E. , Chao T. M. , Lim H. S. , Chou R. , Lam T. J. , Tan C. H.
Published: June 2005

Sperm of secondary male groupers(Epinephelus tauvina), derived from females implanted with 17α‐methyltestosterone (MT), were incubated with [3H]17‐hydroxyprogesterone for 2 hr. The medium was extracted and analyzed by high performance liquid chromatography (HPLC). A single major metabolite with relative retention time corresponding to 17α, 20β‐dihydroxy‐4‐pregnen‐3‐one (17,20α‐P) was produced by the sperm. The metabolite was isopolar with 17, 20α‐P on thin layer chromatography (TLC). The presumptive identify of the metabolite was confirmed to be 17, 20 α‐P when the metabolite was oxidised by periodic acid and the derivative recrystallized with authentic androstenedione to specific constant activity. This experiment indicates that grouper sperm possess the enzyme, 20α‐hydroxysteroid dehydrogenase (20 α‐HSD), and suggests that 17, 20 α‐P may play a role in grouper reproduction. © 1995 Wiley‐Liss, Inc.
Lobster swimmerets: Muscle fiber composition and membrane definition of excitatory synapses in a predominantly fast system
Authors: Govind C. K. , Bevengut Michelle , Pearce Joanne
Published: June 2005

The abdomen of the lobster Homarus americanus has four pairs of segmental appendages, the swimmerets, whose rhythmic beating functions in swimming, righting responses, creating water currents, and aerating eggs. There are 24 separate muscles in each swimmeret and 21 of these are fast, based on their relatively short (4 μm) sarcomeres and six thin filaments orbiting a single thick filament. Three of the 24 muscles are slow with relatively long (7–12 μm) sarcomeres and 8–11 thin filaments surrounding a thick filament. Of the eight functional groups amongst which the 24 muscles are distributed, six groups have only fast muscles, one group has a mixture of fast and slow muscles, and one group only slow muscles. Thus the number and distribution of fast muscles in the swimmeret makes it a predominantly fast system. Motor innervation of two fast muscles in the power‐stroke group reveals numerous excitatory nerve terminals (recognized by circular synaptic vesicles) with well‐defined synaptic contacts and presynaptic dense bars or active zones. Synaptic contacts appear in the P‐face of the fractured nerve membrane as circular plateaus with sparsely distributed particles and one or two small aggregations of large intramembranous particles (putative calcium channels) representing active zones. In the complementary E‐face, synapses assume spherical outlines and active zones appear as shallow depressions. Attachment sites of synaptic vesicles appear as large pits in P‐face or protuberances in E‐face leaflets along the edge of the active zones. The surface features of excitatory synapses of fast swimmeret muscles are similar to those on other crustacean fast and slow muscles. The packing density of large intramembranous particles in the active zones also resembles that in other crustacean muscles thereby suggesting an optimal packing density for these ion channels. © 1995 Wiley‐Liss, Inc.
Time‐dependent effects of daily thermoperiods, feeding, and disturbances on scale allograft survival in the gulf killifish, Fundulus grandis
Authors: Nevid Nicholas J. , Meier Albert H.
Published: June 2005

The length of time required to reject scale allografts was examined in groups of male gulf killifish (Fundulus grandis) treated daily with either 4‐h thermoperiods (daily intervals of 30°C during a 20°C continuum), single meal feedings, or net‐chasing disturbances at one of six different times after the onset of daily photoperiods (LD 12:12 or LD 14:10). Scale allograft survival varied by 30–60% in each timed stimulus experiment as a function of the time of day when the stimulus was provided. The phase relationship between two circadian neuroendocrine oscillations, previously proposed to regulate physiologic and behavioral conditions in gulf killifish, may have important influences on the immune system as well. The phase of one oscillation is thought to be set by the daily photoperiod, and the other is preferentially set by the nonphotic daily stimulus. © 1995 Wiley‐Liss, Inc.
Secretory products of bovine oviductal epithelial cells support the viability and motility of bovine spermatozoa in culture in vitro
Authors: Abe Hiroyuki , Sendai Yutaka , Satoh Takeshi , Hoshi Hiroyoshi
Published: June 2005

The ability of secretions from the bovine oviduct to maintain the viability and motility of bovine spermatozoa was investigated by incubating frozen‐thawed spermatozoa with oviductal flushings, uterine flushings, or the medium from cultures of oviductal epithelial cells and endothelial cells. The flushings obtained from both oviducts and uteri were effective for the maintenance of the viability and motility of spermatozoa, irrespective of the stage of the estrous cycle at which they had been collected. The flushings obtained from the ampullar region of oviducts at the follicular phase of the estrous cycle were most effective for the maintenance of viability and motile activity, for example, the forward motion of spermatozoa. Sperm viability and motility were also maintained by the medium from 6‐hour culture of epithelial cells obtained from oviducts at the follicular phase of the estrous cycle. In contrast, the medium derived from bovine fetal artery endothelial cells had no significant effect on sperm viability and motility. These results suggest that the fluids of the female reproductive tract, in particular, the oviductal fluids at the follicular stage, provide a suitable environment for the maintenance of the viability and motility of bovine spermatozoa. It is also suggested that secretory product(s) of oviductal epithelial cells may play an important role in sustaining both the viability and motility of spermatozoa. © 1995 Wiley‐Liss, Inc.
Immunohistochemical detection of P‐glycoprotein in teleost tissues using mammalian polyclonal and monoclonal antibodies
Authors: Hemmer Michael J. , Courtney Lee A. , Ortego Lisa S.
Published: June 2005

Mammalian P‐glycoprotein is a highly conserved 170‐kD integral plasma membrane protein functioning as an energy‐dependent efflux pump of exogenous and endogenous lipophilic aromatic compounds entering the cell by diffusion. In this study, the tissue specificities of one polyclonal (pAb) and three monoclonal (mAbs) antibodies to mammalian P‐glycoprotein were identified in paraffin‐embedded, parasagittal whole‐body sections of the guppy Poecilia reticulata. Polyclonal antibody mdr(Ab‐1) and mAbs C219, C494, and JSB‐1 demonstrated differential staining patterns in the following tissues: bile canaliculi in the liver, exocrine pancreas, lumenal surface of the intestinal epithelium, renal tubules, interrenal tissue, branchial blood vessels, gas gland, pseudobranch, and the gill transverse septa. Positive P‐glycoprotein expression in P. reticulata correlates well with published results for homologous mammalian tissues of secretory and excretory function. These data indicate that one or more highly conserved members of the P‐glycoprotein transporter family exist in a teleost species and can be detected using commercially available mammalian antibodies. © 1995 Wiley‐Liss, Inc.

This article is a US Government work and, as such, is in the public domain in the United States of America.
Stimulation of human sperm capacitation by purified lipid transfer protein
Authors: Ravnik Stuart E. , Albers John J. , Muller Charles H.
Published: June 2005

Lipid Transfer Protein I is recognized as a key component involved in high density lipoprotein metabolism. We have been studying lipid transfer in relation to sperm capacitation, a complex series of cell surface events required for the acrosome reaction and fertilization. We have previously shown that Lipid Transfer Protein I is present and active in the female reproductive tract. In the present study, we show that purified Lipid Transfer Protein I directly stimulates human sperm capacitation, but not the acrosome reaction, in the absence of other biological effectors. These results provide strong evidence for a novel role for Lipid Transfer Protein I and reveal, for the first time, a potent activator of capacitation, prior to the acrosome reaction. © 1995 Wiley‐Liss, Inc.
CO2 transport in catheterized hydrothermal vent tubeworms, Riftia pachyptila (vestimentifera)
Authors: Felbeck Horst , Turner Patricia J.
Published: June 2005

Isolated plumes and vestimenta of the tubeworm Riftia pachyptila were perfused to determine the form in which carbon is transported to the animal's symbionts via the circulatory system. Catheters supplying colored saline were inserted into an afferent blood vessel while samples were collected from the efferent vessel. During perfusion, the plumes were immersed in sea water containing radiolabeled CO2. The effluent showed radioactivity in inorganic carbonate (∑ CO2, sum of all forms), malate, and succinate. When isolated vestimenta were perfused with saline containing labeled CO2, labeled malate and succinate could be detected in the effluent. Carbon transport in the blood as ∑ CO2 is estimated to be of similar importance to that transported after incorporation into organic carbon. The significance for the establishment of the carbon isotope ratio of tubeworms is discussed. © 1995 Wiley‐Liss, Inc.
Causes of the differences in detection of low frequencies in the auditory receptor organs of two species of bushcrickets
Authors: Kalmring Klaus , Rössler Wolfgang , Hoffmann Elke , Jatho Martin , Unrast Clemens
Published: June 2005

The causes of the differential sensitivity of auditory receptor cells of two tettigoniid species to low‐frequency airborne sound were investigated with neurophysiological, neuroanatomical, and bioacoustic methods. The experiments employed adult males of the Chinese species Gampsocleis gratiosa (Decticinae) and the Australian species Mygalopsis marki (Conocephalinae). G. gratiosa emits very broad‐band songs with a fundamental frequency component at 3.8 kHz, extremely low for a bushcricket; in contrast, the songs of M. marki have a narrow‐band frequency spectrum, from 9 to 25 kHz. Accordingly, the threshold of the auditory organ as a whole is low in the low‐frequency range in the case of G. gratiosa, whereas M. marki is similarly sensitive only at frequencies above 5 kHz.

The experiments were designed to reveal the origin of this sensitivity difference. One possibility considered was that low‐frequency receptors of a particularly sensitive type are present in G. gratiosa and not in M. marki; alternatively, with a similar complement of receptor cells the whole‐organ threshold curve might be expanded or restricted as a result of differences in the lower cutoff frequency of the sound‐conducting system.

The results confirm the latter interpretation. The proximal crista acustica and the distal intermediate organ comprise the same numbers and types of cells in the two species, and the difference in threshold of the low‐frequency receptors is produced by a shift of the frequency range in which the acoustic trachea has an amplifying effect. © 1995 Wiley‐Liss, Inc.
Female reproductive properties and prenatal development of a senescence‐accelerated mouse strain
Authors: Miyamoto Hajime , Manabe Noboru , Mitani Yukiko , Sugimoto Nami , Watanabe Takeshi , Aruga Chinami , Sato Eimei
Published: June 2005

Female reproductive properties, early embryonic development, and serum estradiol and progesterone levels of the senescence‐accelerated mouse (SAM)‐prone (SAM‐P) strain were compared with those of a SAM‐resistant (SAM‐R) strain. The reproductive life span of SAM‐P (from 11.4 to 25.0 weeks old) was shorter than that of SAM‐R (11.1 to 41.6 weeks old), and the total number of SAM‐P pups was 41.7% less than from SAM‐R. The reproductive senescence of SAM‐P is more accelerated than that of SAM‐R. At 15 weeks old, the maximum litter size of SAM‐P was noted and was 33.7% smaller than that of SAM‐R. Although no differences in the numbers of ovulated and fertilized ova were observed between two strains, the number of implants in SAM‐P was 21.6% less than in SAM‐R. Cell cleavage was delayed in embryos of SAM‐P (8% morula, at day 2 of pregnancy) compared to SAM‐R (48%). At day 3 of pregnancy, 9% and 33% of the embryos were blastocysts in SAM‐P and SAM‐R, respectively. At day 1 of pregnancy, serum estradiol level in SAM‐P was 18.2% higher than in SAM‐R, whereas the serum progesterone level in SAM‐P was 46.2% lower than in SAM‐R. The unbalance of estradiol and progesterone levels in SAM‐P was considered to be the cause of the delay in early embryonic development, and then the decrease of implantation and a smaller litter size. © 1995 Wiley‐Liss, Inc.
Monoclonal antibody against a 52 K sperm surface protein inhibits sperm–zona pellucida interactions in the rat
Authors: Dias Alves Marlene S. , Martins Maria Sonia , Pena Sérgio D. J.
Published: June 2005

A major regulatory site for species specificity of fertilization in mammals lies at the level of sperm binding to the zona pellucida. This implies a high degree of complementarity between gamete and receptor molecules. These molecules support species‐specific interactions between sperm and oocyte that lead to gamete fusion (fertilization). We identified a rat sperm head surface antigen using an IgG1 monoclonal antibody (HD1) against rat sperm of epididymis cauda. By electron microscopy the antigen was shown to be present on the plasma membrane surface of the sperm dorsal head. One‐ and two‐dimensional immunoblotting analysis of sperm proteins demonstrated that HD1 reacted only with a 52 K molecule with a pI ranging from 6.6 to 7.2. The 52 K protein was first detected in situ by indirect immunofluorescence and showed to be underlining few elongated spermatids in testis. However, when the sperm reached the epididymis caput, the antigen was seen to be expressed on the dorsal surface of spermatozoa head. A similar fluorescence reaction was detected on sperms in the epididymis corpus and cauda. The specific spermato‐zoa‐zona pellucida interaction was inhibited in the presence of monoclonal antibody HD1 in a sperm binding assay of in vitro fertilization. © 1995 Wiley‐Liss, Inc.
Immunological detection and characterization of an estrus‐associated antigen in the goat oviduct
Authors: Abe Hiroyuki , Onodera Masakazu , Sugawara Shichiro
Published: June 2005

The present study was designed to investigate the possibility that the goat oviduct produces specific substance(s) similar to the oviductal glycoprotein (BOGP) of the bovine oviduct. Oviductal flushings obtained from goats at the follicular and luteal phases of the estrous cycle were examined by immunoblotting for the presence of material that cross‐reacted with monoclonal antibodies (MAbs) specific for BOGP. The MAbs immunoreacted with a broad band with a molecular mass of protein of about 97 kDa in the flushings of goat oviducts after fractionation of proteins by electrophoresis under reducing conditions. The antigen was present in flushings obtained from the ampullar segments of oviducts from goats at the follicular stage, but this antigen could hardly be detected in the flushings from the ampulla at the luteal phase and or the flushings from the isthmus at either the follicular or the luteal phase. This antigen was not detected in uterine flushings, follicular fluid, or serum. An immunohistochemical study demonstrated that the MAbs reacted specifically with the epithelial cells of the goat oviduct. Intense labeling was observed in the ampullar and fimbrial epithelia of goat oviducts at the follicular phase, but the immunohistochemical reaction was very weak at the luteal phase. In the isthmus, the reaction was faint during both the follicular and the luteal phase. No specific immunohistochemical reactivity with the MAbs was observed with other tissues from the reproductive tract or with nonre‐productive tissues. Immunofluorescent staining showed that the antigen was associated with the zona pellucida of goat ovarian eggs that had been incubated with ampullar flushings from goats at the follicular stage. These results indicate that the oviductal epithelial cells of the goat produce an oviduct‐specific antigen that is immunologically and biologically similar to BOGP. © 1995 Wiley‐Liss, Inc.
Effect of light and nutrient restriction on the metabolism of calcium and vitamin D in land snails
Authors: Kriajev Leonid , Edelstein Samuel
Published: June 2005

Biomineralization in invertebrates, such as land snails, may serve as an excellent experimental model for understanding processes of skeletal calcification in higher organisms, the vertebrates. In the present study, the influence of nutrient and light restrictions on the calcification of the shell in land snails was investigated. It was found that nutrient and light restrictions led to an increase in weight and mineral content of shells. These events were accompanied by changes in the metabolism of vitamin D. The molluscan metabolite E was found to accelerate transfer of 45Ca from mantle to shell. On the basis of these findings it is suggested that in land snails adaptation to environmental changes such as light and nutritional restrictions is mediated by the vitamin D endocrine system. © 1995 Wiley‐Liss, Inc.
Modulation of prey‐capture behavior in Plethodon cinereus (Green) (Amphibia: Caudata)
Authors: Maglia Anne M. , Pyles Rebecca A.
Published: June 2005

Many feeding kinematic studies do not identify sources of mechanical variation related to the type or size of prey. Studies of salamanders have concentrated on determining the morphological basis of feeding mechanics or on phylogenetic comparisons; few have examined variability within a species. A series of feeding trials was designed to test whether Plethodon cinereus of different age/size classes exhibits stereotypic patterns in capturing prey of differing type and size. Stopframe video analyses of feedings were made using 19 salamanders of varying body size and four prey types chosen to resemble items in the natural diet of the species. Five morphological features of each salamander, length and width of prey items, and 15 kinematic variables were used to describe each feeding trial.

Statistical analyses of kinematic and morphological variables show that the feeding behavior of this species varies significantly with prey type. Effects of salamander size and prey size within prey types were a source of variation in some kinematic variables; among‐individual variation partitioned with salamander body size. Different feeding modes resulted from distinctive combinations of distances from prey, amount of tongue protrusion, body movements, and duration of mouth closure, which varied with the use of jaw prehension and lingual prey capture. Presence of a repertoire of behaviors, composed of versatile combinations of movements, suggests that Plethodon cinereus modulates feeding mechanics to capture different types of prey. Consideration of natural prey in experiments, and of prey type in comparisons made across taxa, are necessary to investigations of the evolution of feeding behaviors. © 1995 Wiley‐Liss, Inc.
Effects of annetocin, an oxytocin‐related peptide isolated from the earthworm Eisenia foetida, and some putative neurotransmitters on gut motility of the earthworm
Authors: Ukena K. , Oumi T. , Matsushima O. , Ikeda T. , Fujita T. , Minakata H. , Nomoto K.
Published: June 2005

Annetocin, an oxytocin‐related peptide recently isolated from the lumbricid earthworm Eisenia foetida, and putative transmitter substances were examined for their effects on rhythmic, spontaneous contractions of isolated gut preparations of the earthworm. Significant, dose‐dependent effects of the following substances were observed: acetylcholine (ACh), gamma‐aminobutyric acid (GABA), and dopamine were excitatory, while serotonin (5‐HT) and octopamine were inhibitory. Annetocin, oxytocin, and vasotocin stimulated spontaneous contraction of the earthworm gut, annetocin being approximately 10‐fold more potent than oxytocin or vasotocin. However, arginine‐vasopressin (Arg‐vasopressin), lysine‐vasopressin (Lys‐vasopressin), tocinoic acid (N‐terminal hexapeptide fragment of oxytocin), and MSH release‐inhibiting factor (MIF; C‐terminal tripeptide fragment of oxytocin) did not show any effect on the earthworm gut motility. On the other hand, oxytocin, vasotocin, Arg‐vasopressin, Lys‐vasopressin, and tocinoic acid caused spontaneous contractions of isolated rat uterine preparations, where the potency was in this order, while annetocin and MIF exerted no oxytocic activity on the uterus. Dose‐response relationship of the effects of annetocin and its related peptides on the annelid and mammalian systems shows that amino acid residue at the third position of these peptides is important for exertion of excitatory action on the smooth muscle systems. The results in the present study suggest that receptors for annetocin and for GABA on the earthworm gut, unlike those for ACh, desensitize during continuous exposure to these substances. © 1995 Wiley‐Liss, Inc.
Expression of osteopontin in the head process late in gastrulation in the rat
Authors: Thayer Jeanette M. , Giachelli Cecilia M. , Mirkes Philip E. , Schwartz Stephen M.
Published: June 2005

Osteopontin (OPN) is a secreted, glycosylated phosphoprotein. Previous studies have implicated OPN in calcification/decalcification and inflammation. We became interested in developmental expression of OPN because of our previous findings that suggest OPN may play a role in formation of new vascular layers after injury, and because of our observation of developmental regulation in vascular smooth muscle cells. While OPN was expressed at low levels in vessels, only late in development, examination of very early expression patterns revealed a surprising finding. OPN was expressed exclusively in the head process, on day 9.0, late in gastrulation in the rat. In vitro studies of vascular smooth muscle cells have previously demonstrated that OPN promotes cell adhesion and migration. It is suggested that OPN may promote migration of cells, during gastrulation, via integrins which may be present in the head process or overlying ectoderm. © 1995 Wiley‐Liss, Inc.
Replicating DNA does not block germinal vesicle breakdown in mouse oocytes
Authors: Fulka J. , Moor R. M. , Fulka J.
Published: June 2005

Mouse germinal vesicle GV‐G2 stage oocytes were fused to very early S‐phase blastomeres from four cell stage embryos to test whether oocytes have a mechanism which detects replicating DNA and thereafter arrests meiosis at the GV stage. Our results show that oocytes are unable to recognize replicating DNA in transplanted nuclei and undergo germinal vesicle breakdown (GVBD), GVBD and blastomere nucleus breakdown are only blocked by inhibitors of both oocyte maturation and DNA synthesis. These results show that mouse immature oocytes do not possess a feedback control capable of detecting replicating DNA. © 1995 Wiley‐Liss, Inc.
Hamilton connectivity of line graphs and claw‐free graphs
Authors: Hu Zhiquan , Tian Feng , Wei Bing
Published: June 2005

Let G be a graph and let V0 = {ν∈ V(G): dG(ν) = 6}. We show in this paper that: (i) if G is a 6‐connected line graph and if |V0| ≤ 29 or G[V0] contains at most 5 vertex disjoint K4's, then G is Hamilton‐connected; (ii) every 8‐connected claw‐free graph is Hamilton‐connected. Several related results known before are generalized. © 2005 Wiley Periodicals, Inc. J Graph Theory
A generalization of a Ramsey‐type theorem on hypermatchings
Authors: Baginski Paul
Published: June 2005

For an r‐uniform hypergraph G define N(G, l; 2) (N(G, l; ℤn)) as the smallest integer for which there exists an r‐uniform hypergraph H on N(G, l; 2) (N(G,l; ℤn)) vertices with clique(H) < l such that every 2‐coloring (ℤn‐coloring) of the edges of H implies a monochromatic (zero‐sum) copy of G. Our results strengthen a Ramsey‐type theorem of Bialostocki and Dierker on zero‐sum hypermatchings. As a consequence, we show that for any n ≥ 2, r ≥ 2, and l > r + 1, N(n𝒦, l;2) = N(n𝒦, l;ℤn) = (r + 1)n − 1. © 2005 Wiley Periodicals, Inc. J Graph Theory
Vibrational spectral studies of β‐alaninium perchlorate
Authors: Pandiarajan S. , Rajaram R. K. , Ramakrishnan V.
Published: June 2005

Fourier transform (FT) IR and FT‐Raman spectra were recorded at room temperature for crystals of β‐alaninium perchlorate. The observed wavenumbers in both spectra reveal that the amino acid has carbonyl and protonated amino groups that reflect the cationic form of the amino acid. The presence of a carboxyl cyclic dimer structure was revealed. The symmetry of the perchlorate ion is reduced from Td to C2v. Consequently, the degeneracies of a few modes are lifted and these were reflected in the spectra. Copyright © 2005 John Wiley & Sons, Ltd.