bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of actinomycin D, mitomycin C, puromycin, and cycloheximide on desoxycorticosterone‐induced in vitro maturation in oocytes of the catfish, Heteropneustes fossilis (Bloch)
Authors: Goswami Shashi V. , Sundararaj Bangalore I. 
Published: June 2005

AbstractActinomycin D and mitomycin C, inhibitors of DNA‐dependent RNA synthesis, were ineffective in blocking desoxycorticosterone (DOC)‐induced in vitro maturation in oocytes of the catfish, Heteropneustes fossilis (Bloch). This suggests that a concurrent mRNA synthesis is not obligatory for DOC‐induced maturation. On the other hand, cycloheximide and puromycin, inhibitors of protein synthesis, effectively blocked DOC‐induced oocyte maturation; the former was effective at much lower concentrations than the latter. Further, cycloheximide or puromycin completely blocked oocyte maturation when introduced to the culture medium simultaneously with, or within the first three hours of addition of DOC. As the introduction of the inhibitors to the culture medium was delayed, a progressively larger number of oocytes completed the process of maturation. These results indicate that DOC‐induced maturation in the catfish oocytes is contingent upon protein synthesis which takes place within the first three to four hours of DOC stimulation.
Desmosomes and their components after cell dissociation and reaggregation in the presence of cytochalasin B
Authors: Overton Jane , Culver Naomi 
Published: June 2005

AbstractCorneal epithelial cells of the chick, in a stage in which desmosomes are forming, have been dispersed and reassociated in the presence of cytochalasin B in order to assess the affects of the drug on desmosomes. Any affect on these adhesive structures or on normal cell apposition as determined by fine structure would provide morphological evidence for interference with cell adhesion. Dispersed cells in concentrations of cytochalasin B of 3 μg/ml or more showed stabilization of the cell membrane in that after desmosome disruption single plaques remained at the cell surface rather than entering the cytoplasm on vacuoles, as occurs in normal medium. Interference with cell surface apposition particularly at early stages of aggregation provided additional evidence for surface immobility. Despite these effects the presence of a stainable surface coat could be demonstrated early in reaggregation and by 24 hours of culture cell surfaces became closely apposed over wide areas and desmosomes formed between cells and in some cases between different parts of the same cell even in dosages of 10 μg/ml. Thus interference with cell adhesion in corneal cells as measured by these criteria appears to be related to immobility rather than to adhesive properties. These findings bear on studies of cell sorting in the presence of cytochalasin B.
Phenotypic variability of lactate dehydrogenase in Daphnia magna
Authors: Hebert Paul D. N. 
Published: June 2005

AbstractThree zones of L( + ) lactate dehydrogenase (LDH) activity are apparent after electrophoresis of extracts prepared from well fed individuals of Daphnia magna. Phenotypes of individuals subjected to brief starvation are characterized by additional bands below each of the original zones of activity, while prolonged starvation results in the total disappearance of LDH activity in two of the three zones.Proteolysis of pre‐existing LDH molecules is responsible for the appearance of the more anodally migrating components after brief starvation, but the cause of the phenotypic changes after prolonged starvation is uncertain.The possibility of the using LDH phenotypes to monitor changes in food availability within natural populations of D. magna is discussed.
Sperm‐egg interaction in immature hamster oocytes
Authors: Barros C. , Muñoz G. 
Published: June 2005

AbstractImmature oocytes were recovered from ovarian follicles at 0, 2, 4, 6, 8 and 10 hours after an ovulating injection of HCG. The envelopes (cumulus, corona cells and zona pellucida) of these oocytes were removed by enzymic treatment. The naked oocytes were incubated in vitro with capacitated spermatozoa to study the rate of sperm entry.A close correlation existed between the appearance of the ability of the oocyte to effectively interact with capacitated spermatozoa and the stage of nuclear maturation. The lowest percentage of sperm entry into zona‐free oocytes was observed at zero and two hours after the HCG injection. The nuclei of these oocytes were at the germinal vesicle stage and early first meiotic metaphase respectively. A significant increase in the rate of sperm entry was observed in oocytes recovered four hours after the HCG injection. The nuclei of these oocytes were still at the first meiotic metaphase. Percentages of sperm entry similar to controls were observed in oocytes recovered 6, 8 and 10 hours after the HCG injection.Germinal vesicle breakdown and a delay period for nuclear and cytoplasmic materials to interact, seem to be two important factors before gamete fusion can take place.
DNA synthesis during differentiation of tadpole shank epidermis
Authors: Wright Sister Mary L. 
Published: June 2005

AbstractDNA synthesis in the shank epidermis of tadpoles of Rana pipiens was studied by autoradiography with thymidine‐3H. Differentiation of the epidermis at late stages of spontaneous metamorphosis was found to correlate with a peak followed by a slow decline in labeling index in the inner layer, a rapid fall to complete absence of labeling in the outer layer, and a progressive restriction of labeling site to basal cells. Treatment of Stage X tadpoles with 30 μg/liter thryoxine for up to five days accelerated changes in labeling index and differentiation of the epidermis.In three experiments, tadpoles at Stages III, XII and XVIII were treated with thyroxine for intervals of up to 82 hours, and DNA synthesis in the shank epidermis was compared with controls. Whereas at Stage III in the outer layer the labeling index remained the same as the controls except for a slight increase at 12 hours, at Stages XII and XVIII the index fell significantly below the controls by 24 hours. The inner layer labeling index rose significantly above the controls by 12 hours at Stage III, and by 36 hours at Stage XII. At Stage XVIII, the inner layer showed essentially no response to thyroxine. These results indicate an early effect of thyroxine at Stage III, stage‐specific changes in sensitivity of epidermis to thyroxone treatment, and a differential response of outer and inner layers.
The effect of testosterone on the development of the perianal glands of the guinea pig cavia porcellus (L)
Authors: Harmsen R. , Sittig N. 
Published: June 2005

AbstractDaily injections into female and castrate guinea pigs resulted in an increase in size and scent production of the perianal glands. Before testosterone application the glands were significantly smaller than those of entire males. After 45 days of treatment the glands of castrates and females were indistinguishable from the glands of entire males.The perianal glands must be considered secondary sexual characteristics. Social behaviour which is affected by exogenous testosterone may in some cases be affected via interference in the normal scent production.
Hatching, attachment, and outgrowth of mouse blastocysts in vitro: Fixed nitrogen requirements
Authors: Spindle Akiko I. , Pedersen Roger A. 
Published: June 2005

AbstractHatching, attachment and outgrowth of mouse blastocysts in vitro are dependent upon the presence of specific free amino acids in the medium. When grown in Eagle's Basal Medium (BME) containing 1% dialyzed fetal calf serum, 67% of blastocysts hatch. Omission of histidine, methionine, threonine, tryptophan, tyrosine, or valine from BME significantly reduces the incidence of hatching. For attachment to occur, cystine and lysine are also required, and for trophoblastic outgrowth, every essential amino acid except isoleucine is required. Omission of glutamine reduces the extent of outgrowth. Addition of higher (10X–20X BME) concentrations of cystine, histidine, or lysine increases the extent of outgrowth, but addition of 10−5–10−2 M concentrations of non‐essential amino acids does not stimulate either hatching, attachment, or outgrowth.When all essential amino acids are at optimal concentrations, nearly 100% hatching occurs in a chemically defined medium in the absence of a macromolecular fixed nitrogen source. Extensive trophoblastic outgrowth and inner cell mass growth occur at optimal amino acid concentrations, but only in the presence of serum. Under these conditions, a collagen substrate is not necessary for growth and differentiation of the inner cell mass into endoderm and ectoderm in vitro. These requirements indicate that during post‐blastocyst development in vitro the mouse embryo gradually becomes dependent upon specific exogenous fixed nitrogen sources, including essential amino acids and a non‐dialyzable component from serum.
Hypertrophy of the rat urinary bladder following reduction of its functional volume
Authors: Peterson Christine M. , Goss Richard J. , Atryzek Vladimir 
Published: June 2005

AbstractIf the functional volume of the rat urinary bladder is reduced by injecting varying quantities of a 50:50 melted mixture of paraffin and vaseline, the capacity of the bladder increases so as to provide the extra space needed to accommodate for the storage of urine. By four weeks, such bladders were found to have hypertrophied roughly in proportion to the size of the bolus of paraffin‐vaseline they contained.
In vitro fertilizability of rabbit ova from donors isoimmunized with sperm
Authors: Russo Irma , Metz Charles B. 
Published: June 2005

AbstractOvulated ova in cumulus masses were obtained from rabbits following isoimmunization with rabbit sperm. They were inseminated in vitro with capacitated sperm, cultured and examined for cleavage and cumulus dispersion. In five experiments only 11 of the 81 (13.6%) ova from the immunized females cleaved compared to 15 out of 41 (36.5%) from the inseminated control females. The cumulus masses of ova from immunized donors dispersed more slowly than controls following insemination.
Yolk proteins in Drosophila: Identification and site of synthesis
Authors: Gelti‐Douka H. , Gingeras T. R. , Kambysellis M. P. 
Published: June 2005

AbstractThe yolk proteins from several Drosophila species were identified and partially purified. One or two predominant proteins were found in the crude extracts of mature oocytes and in the hemolymph of mature females. They were absent or present in trace amounts in male and young female hemolymph. Fat body from mature D. silvestris cultured in Grace's insect culture medium, synthesized and released several proteins, two of which were precipitable by antibodies against silvestris crude yolk extract. Fat body from immature flies synthesized and released only one of these proteins.
Changes in SS linked structures of the sperm tail during epididymal maturation, with comparative observations in sub‐mammalian species
Authors: Bedford J. M. , Calvin H. I. 
Published: June 2005

AbstractTreatment of immature and mature epididymal spermatozoa with SDS and DTT reveals differences in the structural character of their respective tail organelles as a function of their maturity, which are not apparent in untreated spermatozoa. The response of mature sperm tails of rat, rabbit and other mammals to these reagents indicates that the segmented connecting pieces, the coarse outer fibers, the outer membrane of the mitochondrion and the fibrous sheath of the principal piece, as well as the relationships between these organelles, are stabilized highly by intermolecular SS crosslinks. The disruption of these structures by SDS alone in caput epididymal spermatozoa, however, implies their stabilization by disulfide bonds during sperm passage through the epididymis. Hence the pattern of flagellar beat seen typically in mature epididymal or ejaculated spermatozoa is probably determined by post‐spermiation changes in the structural as well as in the metabolic properties of the tail organelles.In similar studies of a wide variety of sub‐mammalian species, the sperm tails fell into two broad classes. The “simple” tail, a plasma membrane enclosing only mitochondria and microtubule doublets (teleosts, frog, chicken and pigeon), disappeared immediately in SDS, though a partial SS dependent stability was inducible in the microtubules of teleost sperm tails. In the second class, the coarse fibers, arrayed as a nine‐membered ring (octopus, snake, lizard, turtle and sparrow) or otherwise (skate, newt), and the fibrous sheath (snake, lizard) also are stabilized by SS bonds, as is the undulating membrane of the urodele sperm tail.Since the sperm mitochondria in all sub‐mammalian species were totally disrupted by SDS alone, an extreme SS dependent stability of the outer mitochondrial membrane may well be a feature unique to mammalian spermatozoa.
Pituitary regulation of appetite and growth in the turtles Pseudomys scripta elegans and Chelydra serpentina
Authors: Brown Patricia Stocking , Giuliano Ralph , Hough Gerard 
Published: June 2005

AbstractEleven weeks of treatment with growth hormone (20 μg 3 times/wk) and prolactin (20 μg 3 times/wk) increased the size of immature Pseudomys scripta elegans beyond controls. Food consumption was controlled so that all effects of the hormones were direct ones on growth and not due to hyperphagia. Hypophysectomy decreased growth, food consumption and liver protein in Chelydra serpentina. Growth hormone replacement (20 μg/2 days) in hypophysectomized animals increased growth, food consumption, liver protein, liver water and decreased liver lipid and liver glycogen compared to hypophysectomized animals. In intact Chelydra serpentina, growth hormone (5 and 50 μg/2 days) also increased appetite, growth, liver protein, liver water and decreased liver lipid and glycogen. Blood sugar was not altered by growth hormone treatment.
The effects of light and sympathetic innervation to the head on nidation in mink
Authors: Murphy Bruce D. , James Derek A. 
Published: June 2005

AbstractNinety primaparae female mink were bred on two consecutive days between March 11–15. Six days after first mating mink were subjected to one of the nine treatments, control (n = 21); sham superior cervical ganglionectomy (Sham SCGX) (n = 5); bilateral orbital enucleation (n = 10); bilateral orbital enucleation and constant light (n = 16); constant light (n = 19); an accelerated photoperiod of 15L, 9D + 5 min of light per day (cumulative) (n = 10); an accelerated photoperiod and SCGX (n = 6); SCGX and environmental light (n = 5); bilateral orbital enucleation and SCGX (n = 5). The interval between first mating and calculated date of nidation [copulation to implantation (CI) interval] was compared among groups. CI interval was significantly abbreviated in accelerated photoperiod treated animals, and significantly lengthened by constant light; blindness regardless of light regime; and SCGX with accelerated photoperiod. Nonsignificant variation in the CI interval was observed in the blinded or environmental light treated SCGX animals that underwent implantation. Reproductive failure, defined as either absence of embryos in necropsied animals or failure to whelp by females alive on June 1, occurred less frequently in accelerated photoperiod animals and with considerably greater frequency in blind, SCGX, or constant light treated intact animals. Observations in blinded animals suggest that this treatment and presumably SCGX and constant light extend the period of embryonic diapause to the point of blastocyst degeneration resulting in reproductive failure. The occurrence of nidation in some blinded, and constant light animals indicates that this event can occur independent of either retinal receptor or photoperiod. The effects of SCGX suggest that the pineal body is either not involved in nidation or has a facilitatory rather than inhibitory role.
A somatic cell approach to the genetic analysis of the laboratory mouse
Authors: Kozak Christine , Nichols Elizabeth A. , Ruddle Frank H. 
Published: June 2005

AbstractThe determination of gene linkage in the laboratory mouse was approached through somatic cell techniques. Cells of an established line of Chinese hamster lung fibroblasts, E‐36, were fused with a population of mouse macrophages obtained from the AHe/J inbred strain. A total of 62 primary and secondary clones were isolated in HAT selective medium and characterized for the segregation of 12 murine enzyme markers by starch gel electrophoresis. While all other enzymes segregated nonrandomly, GPI was generally retained. Twelve subclones were isolated in medium containing 8‐azaguanine to determine whether this retention was due to a syntenic relationship between GPI and the enzymes of the salvage pathway of purine biosynthesis necessary for growth in HAT, but were found to express murine GPI. Of the other enzymes examined, MOD and MPI were determined to be syntenic and the others segregated independently of each other.
Temperature and prolactin as control factors in newt forelimb regeneration
Authors: Schauble Muriel K. , Nentwig M. Ruth 
Published: June 2005

AbstractTemperature and prolactin were studied as control factors in the process of newt forelimb regeneration. Temperature was varied in five steps from 10° to 30°C under otherwise constant environmental conditions. Longitudinal new growth and limb differentiation were observed. Temperature was found to have a profound effect upon both developmental processes. Maximal longitudinal new growth resulting from changes in temperature alone occurred at 25°C with maximal limb differentiation at 30°C. At each temperature studied, prolactin enhanced both new growth and limb differentiation. With prolactin, maximum new growth also occurred at 25°C, but maximum limb differentiation occurred at 20°C. For our purposes optimum limb development was defined as the greatest new growth commensurate with full normal development. This optimum was reached by prolactin treated animals at 20°C when the regenerating limbs studied achieved 100% maximum normal differentiation and 87% maximum new growth. It was possible by employing a combination of temperature changes and hormone administration to control newt forelimb regeneration and produce a whole spectrum of limb development.
Partial purification of the crowding factor from Carassius auratus and Cyprinus carpio
Authors: Pfuderer Peter , Williams Penney , Francis A. A. 
Published: June 2005

AbstractCrowding factors are those substances released by fish, which, under crowded conditions, inhibit both their growth and reproduction and depress their heart rate. We have partially purified the crowding factor from goldfish and carp by following a heart‐rate‐depression assay. The heart‐rate‐depression activity eluted with the diglyceride fraction from both silicic acid and Sephedex LH‐20. A slightly different activity eluted with the free sterols. The peak activity associated with the diglycerides has a distinctive ultraviolet spectrum distinguishable from that of phthalic acid esters, which are also active in the assay sytem and are found in fish tissues and fish water.
Inhibitory effect of dibutyryl cAMP on mouse oocyte maturation in vitro
Authors: Cho Wan Kyoo , Stern Samuel , Biggers John D. 
Published: June 2005

AbstractThe effects of dibutyryl cyclic AMP on the maturation of the mouse oocyte in vitro were studied. It was found that concentrations of 100 μg/ml or greater prevented germinal vesicle breakdown in more than 95% of the treated oocytes. The inhibition of maturation was found to be a reversible phenomenon. When oocytes were exposed to the drug after the completion of germinal vesicle breakdown, no effect of the drug was noted. Thus, dibutyryl cyclic AMP appears to effect only the initial stages of meiotic maturation in the mouse oocyte.Theophylline was also found to inhibit maturation, suggesting that increased levels of cyclic AMP in the oocyte may be the causative agent of the inhibition of maturation.
Caudal neurosecretory system: Possible role in pheromone production
Authors: Richards I. S. 
Published: June 2005

AbstractIsolated brown bullhead catfish, Ictalurus nebulosus, were conditioned to discriminate between water samples from aquaria containing solitary conspecifics. Urine and extracts of urophyses, thoracic spinal cord, integument, gill and urinary bladder were then assayed to determine if they were active in effecting this discrimination. Urine and urophyseal extracts were consistently most active as sources of chemical information.
Analysis of chemotaxis in the nematode Caenorhabditis elegans by countercurrent separation
Authors: Dusenbery David B. 
Published: June 2005

AbstractC. elegans responds to several common chemicals. Comparisons of pairs of ions at equivalent concentrations indicated orders of attractiveness of:

The least attractive pair of ions, calcium acetate, is attractive, indicating all these ions are attractive. The most attractive pair, sodium chloride, was attractive from a threshold of 0.1 mM to at least 50 mM. The response to NaCl was maximal throughout the temperature range 15 to 25°C and the pH range 3.0 to 9.0. Acid was avoided and base was attractive from concentrations of 0.1 to 1 mM. Dissolved CO2 in the concentration range 0.1 to 1 mM was attractive in 10 mM sodium borate buffer, pH 8.8, but avoided in 25 mM potassium phosphate, pH 6.0. All these responses are likely to affect the distribution of C. elegans in nature and they also provide a tool for promising studies in neurogenetics.
The quantities of venom injected into prey of different size by Vipera palaestinae in a single bite
Authors: Allon Nahum , Kochva Elazar 
Published: June 2005

AbstractThe quantity of venom injected by a snake is one of the most important factors determining the danger of the bite. The present study tests whether the amount injected is in correlation with the size of the prey.Seven specimens of Vipera palaestinae injected with 14C‐amino acids in order to label the venom, were offered three pairs of one mouse and one rat each. The amounts of venom injected into either prey were variable, ranging from zero to more than 200 mg. In most cases 50 mg were injected, approximately 8% of the total venom available in the glands. In three snakes the average amount injected into rats was two to three times higher than that injected into mice; in two snakes the mice received three to ten times more than the rats, while in two snakes there was no difference between the amounts injected into either prey.It is concluded that the size of the prey does not necessarily influence the amount of venom injected by the snake.
Supernumerary limb induction in the anura
Authors: Balinsky B. I. 
Published: June 2005

AbstractInduction of supernumerary limbs in Bufo tadpoles was achieved by transplanting the transverse neural fold with adjoining tissue from neurulae into tail bud stage embryos. The graft differentiated into brain, eyes, noses and mouthparts. Induced limb rudiments were associated with either noses or mouthparts. The author rejects the suggestion made by Perri that the induction is due to release of products of cytolysis from the graft and suggests that limb induction is due to a disorganization or reduction of the subepidermal basement membrane (layer of collagen fibres) by certain grafts, and that as a result the potentially limb forming flank mesenchyme is allowed to interact with the epidermis — a precondition for limb development. In support of this view the author presents electronmicrographs in which it is shown that at the edge of the nostril, and on the mouthparts (lips, oral papillae), the basal membrane is attenuated and disorganised, allowing processes of mesenchyme cells to penetrate through the layer of collagen fibres and reach the inner surface of the epidermis.