bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and inhibition of macronuclear DNA in regenerating Blepharisma
Authors: Gavurin Lillian , Hirshfield Henry I.
Published: June 2005

The macronuclear cycle in regenerating posterior fragments of albino Blepharisma intermedium consists of four sequential stages which result in the reversible condensation of the macronucleus, and which are similar to those in the pigmented strain. Tritiated deoxyuridine incorporation occurs predominantly during the first three hours of regeneration and then declines. Of the early hours, hour 2 exhibits a significant increase in the proportion of heavily‐labeled cells. A statistical comparison of whole organisms labeled through exposure to radioactive precursor for a one‐hour period with fragments labeled at each hour of regeneration reveals a significantly greater number of labeled fragments for each of hours 1 through 4. Asynchronous patterns of DNA replication are evident in the macronucleus of both regenerating and whole cells. Oval‐shaped pellicular rings, consisting of dense accumulations of silver halide grains are evident during hours 5 and 6 of regeneration.

Continuous inhibition of DNA synthesis during regeneration produces effects which depend upon the specific inhibitor employed. 5‐Aminouracil (AU) effects an appreciable delay of regeneration, without lethal or abnormal consequences. AU, hydroxyurea (HU), 5 bromodcoxyuridine (BUdR) and 5‐fluorodeoxyuridine (FUdR) exhibit a marked inhibitory effect upon division when they are administered to two‐hour fragments. The first three hours of regeneration is the period of greatest susceptibility to inhibitor action with respect to post‐regeneration division. AU, BUdR and FUdR interfere with the sequence of macronuclear events when these inhibitors are administered during hours 2–4 of regeneration. Contracted macronuclei are present at 24 hours and are related to division delay. HU, FUdR and BUdR treatment, during the later hours of regeneration, results in macronuclear fragmentation, branching and abnormal massing, respectively. Cytoplasmic abnormalities result from fragment exposure to the inhibitors during hours 4–6, with BUdR producing the most pronounced effects.
Studies on differentiation of Müllerian ducts in the quail, Coturnix coturnix japonica. II. Effects of sex hormones on nucleic acid synthesis in isolated female ducts
Authors: Iwamura Yukio , Koshihara Hidetoshi , Noumura Tetsuo
Published: June 2005

The present investigations were carried out in an effort to determine the mechanisms underlying differentiation in the avian Müllerian duct, especially the asymmetrical differentiation of the female ducts.

Using the isolated female ducts of Japanese quail, the incorporations of 3H‐uridine and 14C‐thymidine were determined in vitro at several embryonic stages. Incorporation of 3H‐uridine was altered with some synchronous fluctuation during the embryonic period in both the left and right ducts, while 14C‐thymidine incorporation first decreased rapidly and subsequently, only slightly, during the same period.

By administering sex hormones in vitro nucleotide incorporation was affected to an appreciable extent characteristic of the duct at each stage. This hormonal susceptibility was also periodically altered during duct differentiation. The growing left duct continued to receive an apparent stimulation under the hormonal conditions, while the involuting right duct was sometimes inhibited under the same conditions.

Such hormonal susceptibilities may explain the asymmetrical differentiation of the female left and right ducts during this embryonic period.
Protein synthesis by the accessory gland of male house cricket, Acheta domesticus
Authors: Kaulenas M. S. , Yenofsky R. L. , Potswald H. E. , Burns A. L.
Published: June 2005

The accessory gland in male Acheta domesticus consists of several hundred tubules of variable length. The secretory cells of the tubules, which are very richly endowed with rough endoplasmic reticulum, surround a central cavity filled with product proteins. The proteins produced by the gland have been characterized by SDS‐polyacrylamide gel electrophoresis and gradient centrifugation. They constitute a complex mixture with a wide range in molecular weights and charge properties. The mRNAs for the proteins appear to be of long half‐life.

Extensive regional specialization exists in the gland with respect to the types of export proteins formed. For the total gland, the acquisition of the full range of protein synthetic capacity is triggered by the imaginal molt, while the differentiation and growth of the tubules can continue in the absence of the molt.
Phenogenetics of the eyeless‐Dominant mutant of Drosophila melanogaster. II. Involvement of the nervous system
Authors: Arking Robert , Putnam Richard L. , Schubiger Margrit
Published: June 2005

The eyeless‐Dominant (eyD) mutation is a fourth chromosome insertional translocation which affects the eyes, antennae, ocelli, and sexcombs when heterozygous but is a larval‐pupal lethal when homozygous. By use of a crowding technique, it was possible to separate eyD homozygotes and heterozygotes with 100% accuracy at an early stage of larval development. Under these conditions, the eyD homozygotes had a biphasic lethal period since 45% died as first or second instar larvae and 55% died as pupae. The eyD/eyD pupal lethal, isolated by this technique, was able to form all the adult structures with the exception of the eye‐antennal disc derivatives. The brain was present but abnormal. In testing the competence of the eyD/eyD larval eye discs by means of transplantation experiments, it has been demonstrated that the mutant discs develop non‐autonomously. Histological studies have revealed the existence of neurological defects in both eyD heterozygotes and homozygotes. The eyD/eyD lethal larvae lacked detectable optic formation centers and showed an extreme reduction in the number of cells present in the cortex of the brain. The eyD/eyD lethal pupae possessed partial formation centers and also had severe reduction in the number of cortical cells. The eyD heterozygotes possessed normal appearing formation centers but they did exhibit a moderate reduction in the number of their cortical cells as compared to wild‐type. These studies have shown that there is a direct correlation between the extent of neurological damage and the time of developmental arrest. It appears that the eyD mutation must adversely affect the neuroblasts at a very early stage of development. As a working hypothesis, it is suggested that the eyD mutation operates via the same basic mechanism of cell death in heterozygous and homozygous animals.
Comparative immunology of Galapagos iguana hemoglobins
Authors: Higgins Paul J. , Rand Charles S.
Published: June 2005

The antigenic properties of the major hemoglobin component of the Galapgaos iguanas were studied using second‐approximation qualitative and quantitative immunochemical techniques. Phylogenetic distances, relative to the Galapagos marine iguana. Amblyrhynchus cristatus, were established on the basis of immunological cross‐reactions.
The effect of pancreatectomy on the survival of Anguilla rostrata in different salinities
Authors: Epple August , Lewis Thomas L.
Published: June 2005

Pancreatectomized yellow eel survive well in fresh water, but very poorly in sea water. The possibility is discussed that these observations reflect a direct effect of islet hormones on the osmoregulation.
Adrenocortical function: Corticosterone levels in female BALB/c and C3H mice under various conditions
Authors: Hawkins Edward F. , Young Patricia N. , Hawkins Andrea M. C. , Bern Howard A.
Published: June 2005

A diurnal rhythmicity in plasma corticosterone levels was demonstrated in female BALB/cCrgl and C3H/Crgl mice, with and without mammary tumor virus. Removal of the adrenals followed by metopirone treatment reduced circulating corticoid to non‐detectable levels in C3H but not in BALB/c mice. Dexamethasone reduced but did not abolish corticosteroid secretion in both strains. Neonatal exposure to exogenous hormones failed to cause any obvious change in corticoid levels. Bilateral ovariectomy of these neonatally treated mice at 40 days of age resulted in a subsequent lowering of plasma corticoid levels when compared with intact animals.
The effects of acetylcholine, biogenic amines and other vasoactive agents on the cardiovascular functions of the eel, Anguilla japonica
Authors: Chan D. K. O. , Chow P. H.
Published: June 2005

The blood pressure in the cardinal vein, cardiac chambers and ventral and dorsal aortae have been recorded from conscious eels in water. At low doses, acetylcholine reduced the heart rate but increased the transbranchial differential blood pressure. The effects were abolished by atropine but not by tubocurarine. At doses in excess of 0.1 μg/kg, a secondary rise in arterial blood pressure was observed which could be abolished by bretylium, phentolamine or phenoxybenzamine.

Catecholamines did not affect the heart rate although a transient bradycardia due to reflex inhibition could be observed with adrenaline and noradrenaline. Catecholamines increased the cardiac contractile force through an α‐adrenergic mechanism which was blocked by phentolamine but not by propranolol. The relative potency was noradrenaline > adrenaline≫isoprenaline. A β‐adrenergic receptor located in the branchial circulation led to vasodilation and decrease in transbranchial differential pressure. Both α‐(vasoconstriction) and β‐(vasodilation) adrenergic receptors were present in the systemic circulation.

Dopamine, 5‐HT, GABA and bradykinin caused bradycardia abolishable by vagotomy or atropine treatment. Angiotensin II was hypertensive but did not affect the heart rate nor the transbranchial differential pressure. Tyramine caused release of endogenous catecholamines. With repeated doses, tachyphylaxis to the drug was observed. Histamine was without any obvious cardiovascular effects in the eel.
Effects of interactions with older males on behavior and reproductive development in first‐year male red‐winged blackbirds Agelaius phoeniceus
Authors: Wiley R. Haven , Hartnett Sue A.
Published: June 2005

Male red‐winged blackbirds Agelaius phoeniceus in their first year normally do not establish territories or breed. To investigate the possibility that interactions with older males might inhibit reproductive development of young males, we compared the behavior of first‐year males in the presence and absence of older males. For three months during the first half of the breeding season, we studied mixed‐ and single‐age groups of three males in standardized outdoor aviaries: two groups of three first‐year males (FFF groups), two groups of one older and two first‐year males (AFF groups), and one group of three older males (AAA group). In all groups one male established clear dominance, invariably the older male in AFF groups. The dominant male in FFF groups displaced subordinates less frequently than did the dominant older male in AFF groups early in the season, but equally frequently later. In May the largest testis weights of males in FFF groups were significantly lower than those of dominant older males in AFF groups. First‐year males in the absence of direct interactions with older males can achieve levels of aggressive behavior comparable to those of a dominant older male in similar social environments but the seasonal development of their aggressive behavior occurs later and their testes in May are smaller than dominant adults'. This delay in the seasonal development of aggressive behavior in first‐year males, independent of the immediate social environment, suggests that the age‐dependent territoriality of males in this species is not strongly regulated by effects of older males on the development of younger males.
Differential gene expression in multilocus isozyme systems of the developing green sunfish
Authors: Champion Michael J. , Whitt Gregory S.
Published: June 2005

The patterns of expression of eight multilocus isozyme systems were investigated in the differentiated adult tissues and the early embryonic stages (0‐210 hours after fertilization) of the green sunfish, Lepomis cyanellus. Enzymes encoded by approximately 23 gene loci were resolved by starch‐gel electrophoresis and detected by specific histochemical staining. The developmental patterns of these isozyme systems appear to be the result of the differential expression of the multiple gene loci. Isozymic forms of glucosephosphate isomerase (GPI‐A2), malate dehydrogenase (MDH‐A2), and creatine kinase (CK‐C2) were present in most differentiated tissues, in the unfertilized egg, and in all stages of embryonic development. Closely homologous forms of these isozymes (GPI‐B2, MDH‐B2, and CK‐A2) were expressed predominantly in skeletal muscle and were first detected at around the time of hatching (38‐42 hours). The similar temporal and spatial patterns of gene expressions for the GPI, LDH, MDH, and CK loci suggest that the duplicate loci encoding isozymes, diverged in their regulation to patterns of differential gene expression which are similar for each enzyme system.
The effect of metabolites of testosterone on the development of fertilizing ability by spermatozoa in the epididymis of castrated hamsters
Authors: Lubicz‐Nawrocki C. M.
Published: June 2005

The effects, of testosterone, 17βT‐hydroxy‐5α‐androstane‐3‐one (5α‐dihydrotestosterone; 5α‐DHT), 5α‐androstane‐3α, 17βT‐diol (3α‐androstanediol; 3α‐diol) and 5α‐androstane‐3βT, 17βT‐diol (3βT‐androstanediol; 3βT‐diol) on the development of fertilizing ability by spermatozoa in the epididymis were compared in castrated hamsters. The left corpus epididymidis was ligated for 14 days in intact and castrated animals to prevent the in‐flow of spermatozoa into the cauda epididymidis and the ductuli efferentes were bilaterally ligated. The fertilization rate of spermatozoa in the left cauda epididymidis of control animals decreased to 71.1% after 14 days whereas that of spermatozoa in the unobstructed right cauda epididymidis remained at the control level of 100%. After castration, 50 μg testosterone, 25 μg 5α‐DHT and only 9 μg 3α‐diol/day were the minimal doses that facilitated normal development of fertilizing ability but 75 μg testosterone, 37.5 μg 5α‐DHT and 12.5 μg 3α‐diol/day were required to maintain sperm survival at the control level. However, 3βT‐diol was ineffective for both sperm maturation and survival.
Intercellular junctions in the Xenopus embryo prior to gastrulation
Authors: Sanders E. J. , Dicaprio R. A.
Published: June 2005

A freeze‐fracture study of Xenopus embryos at the eight‐cell stage revealed the presence of tight junctions and small aggregations of 120 Å diameter intramembranous particles. These aggregations consited of up to ten particles and resembled forming gap junctions. Examination of early blastulae showed that fully developed gap junctions were present, apparently occuring very infrequently. These results support the contention that specialized junctions mediate electrical coupling during early amphibian development.
A scanning electron microscopic and flame spectrometry study on the role of Ca2+ in amphibian neurulation using papaverine inhibition and ionophore induction of morphogenetic movement
Authors: Moran Denis J.
Published: June 2005

SEM observations reveal that papaverine, which interferes with Ca2+ flux, inhibits neural fold formation causing a flattening of the cellular surface and a broadening of cellular junctions. Ionophore A23187 and EGTA both counter this effect promoting a rapid cellular constriction which results in the formation of neural ridges and folds as individual cells become uplifted and ruffled. Flame spectrometry data indicate that as Ambystoma maculatum or mexicanum embryos neurulate Ca2+ is released to the medium, a condition which is impeded by papaverine. Ionophore A23187 induces Ca2+ influx whereas EGTA induces an efflux. Since both agents affect similar morphological changes it is suggested that the availability of free Ca2+ is crucial in controlling the morphogenetic movements of neurulation. It is now apparent that neuro‐axial development in the urodele is accompanied by a Ca2+ efflux, but the mechanism(s) responsible for the ion's release is unknown.
A sexual aggregating pheromone system in the zebrafish, Brachydanio rerio (hamilton‐buchanan)
Authors: Bloom Herbert D. , Perlmutter Alfred
Published: June 2005

Zebrafish, Brachydanio rerio, when placed in a T‐maze demonstrated preference for, or avoidance of, donor water produced when specified numbers of conspecifics of either sex were kept in holding systems for specific lengths of time. Inter‐ and intrasexual attractions were found to occur in different ranges of concentration of the attractant material(s). Insufficient or excessive concentrations of the attractant(s) failed to elicit the attractant response. The proposed pheromone attractant was shown to be removable from the aquatic environment. Its possible role in the behavioral aspects of schooling and spawning is discussed.
An autoradiographic evaluation of the regeneration of corneal epithelium in Bufo marinus
Authors: Grillo R. S. , Knowles B. A. , Cooperstein D. F.
Published: June 2005

Epithelial regeneration following scraping of a central portion of corneal epithelium of the toad, Bufo marinus, was studied. Wound closure occurred by migration of a single layer of epithelial cells from adjacent noninjured areas. Autoradiography indicated that following wound closure at two days after scraping, DNA synthesis began in these epithelial cells covering the former scraped area, and was even more pronounced three days after scraping. At four days the former denuded area was covered by an epithelium two to four cells thick and by the fifth day regeneration was complete. These studies also indicated that mitotic time in this organism is rapid.
Localization of mouse Pgk‐2 gene at the D end of the H‐2 complex
Authors: Vandeberg John L. , Klein Jan
Published: June 2005

A survey of the Pgk‐2 alleles carried by H‐2 congenic lines of mice has established that the Pgk‐2 locus is near the D end of the H‐2 complex on chromosome 17. A comparison among inbred strains of the alleles for Pgk‐2, H‐2, and two other genes in this vicinity, Tla and Ce‐2, has revealed a remarkable correlation suggestive of strong linkage disequilibrium in the wild mice from which the inbred strains were derived.
Ultrastructural localization of adenyl cyclase activity in neoblasts of turbellarian Dugesia lugubris (O. schmidt)
Authors: Moraczewski Jerzy , Duma Anna
Published: June 2005

AC was localized cytochemically for the first time in tissues of lower Metazoa. Qualitative differences were found in the distribution of AC in the neoblasts of non‐regenerating and regenerating turbellarians. Changes were observed in AC activity during the course of regeneration.
Strain differences in the immune response of mice to homologous sperm‐specific lactate dehydrogenase (LDH‐C4)
Authors: Kille John W. , Wheat Thomas E. , Mitchell Graham , Goldberg Erwin
Published: June 2005

The sperm‐specific isozyme of murine lactate dehydrogenase (LDH‐C4 was injected into female mice of various strains. Two regulatory phenotypes characterize the resultant immunity to LDH‐C4: one is manifested by high, intermediate or low levels of response, the other by the immediate or delayed maturation of peak titer. The response of several strains can be classified as high (SWR, SJL, BABL/c, C3H/He) and intermediate to low (A, CBA, DBA/2, DBA/1, C57BL/6) according to the level of antibody production and cell mediated immunity. BALB/c, SJL and SWR strains are immediate responders while and C3H/He mice are clearly delayed responders. Maturation and magnitude of response do not appear to be related. Both the antibody and cell mediated responses are T‐dependent, but are not obviously associated with Ig allotype or H‐2 regulation.
The influence of acclimation temperature on the fatty acid composition of an aquatic Crustacean (Carcinus maenas)
Authors: Chapelle Serge
Published: June 2005

Crabs (Carcinus maenas) were acclimated to temperatures of 7, 14 and 27°C and the fatty acid pattern of lipids from muscle, gills and hepatopancreas were determined. There was an overall tendency for the degree of unsaturation of fatty acids to decrease with an increase in acclimation temperatures. The greatest differences was observed in the relative content of C16:0, C16:1, C18:0, C18:1, C20:5 and C22:6 fatty acids. It is suggested that acclimation involves the ability to control the degree of unsaturation of cellular lipids in order to maintain a specific liquid‐crystalline state of biomembranes and to check the activity of certain enzymes implicated into lipoproteins of the cellular membranes. A significant enhancement of degree of unsaturation of the phosphatidylethanolamine and of the phosphatidylcholine was noted at lower temperatures. No or less pronounced changes occurred in triglycerides, phosphatidylserine and phosphatidylinositol. It is suggested that the acyltransferases, catalysing the conversion of lysophospholipid into phospholipid have an important regulatory role in the maintenance of a specific fatty‐acid pattern of principal phospholipids.
Selective incorporation of selenium‐75 into a polypeptide of the rat sperm tail
Authors: Calvin Harold I.
Published: June 2005

Selenium is necessary for normal sperm tail development in the rat. The biochemical locus of this requirement was investigated by intratesticular administration of (75Se)Se03−2. Sperm were labeled primarily in tail keratin, a disulfide‐stabilized fraction obtained by extracting isolated tails with sodium dodecyl sulfate (SDS). By incubation in 1% SDS−0.2 mM dithiothreitol, followed by sonication and centrifugation, the 75Se was separated from a residue rich in S and Zn, composed of dense fibers and connecting pieces. The extracted 75Se‐labeled material was non‐dialyzable, sensitive to pronase, retained most of its bound isotope following carboxymethylation, and displayed only one radioactive component, of 17,000 daltons, during SDS‐polyacrylamide gel electrophoresis. It is suggested that the labeled moiety is a selenopolypeptide whose function is critical for normal assembly of the sperm tail.
Enhanced identification of lethal yellow (Ay/Ay) mouse embryos by means of delayed development of four‐cell stages
Authors: Granholm Nels H. , Johnson Phyllis M.
Published: June 2005

At present, experimental studies on the primary genetic lesion in Ay/Ay embryos are restricted by the absence of techniques designed to identify Ay homozygotes prior to the onset of secondary defects. This paper describes a methodology to enrich the yields of Ay homozygotes in experimental populations by taking advantage of an early homozygous Ay expression‐lagging development in 4‐cell embryos.
Effects of hydrostatic pressure on (Na+ + K+)‐ATPase and Mg2+‐ATPase in gills of marine teleost fish
Authors: Pfeiler Edward
Published: June 2005

The effects of hydrostatic pressure on branchial NaK‐ATPase and Mg‐ATPase activities were studied in two species of marine teleost fish: the relatively shallow water Scorpaena guttata, collected from a depth of 20 m, and the deeper living Anoplopoma fimbria, collected from a depth of 310 m. Specific activities in gill microsomes, measured at 18oC, were similar in both species, with the NaK‐ATPase usually comprising about 30–40% of the total ATPase activity. NaK‐ATPase activity of S. guttata was activated by low hydrostatic pressure (68 atm) but activity was inhibited at pressures above 136 atm. The NaK‐ATPase of A. fimbria showed a similar activation at low hydrostatic pressure but was less sensitive to a pressure of 340 atm than the enzymefrom S. guttata. At a pressure of 476 atm, the NaK‐ATPase activity of both species was inhibited to the same extent. The Mg‐ATPase of both species was activated by pressure (maximal activation occurred at 136 atm), but in contrast to the NaK‐ATPase, remained activated at all pressures tested. Solubilization of the enzymes from gill microsomes of A. fimbria with Lubrol WX did not significantly alter the pressure responses. Inhibition of NaK‐ATPase at high pressure was reversible upon release of pressure. Inhibition of branchial NaK‐ATPase in both species occurred at pressures higher than the fish normally experience in their environment.
Comparative study on horseshoe crab coagulogens
Authors: Shishikura F. , Sekiguchi K.
Published: June 2005

Coagulogens prepared from four species of horseshoe crabs, Tachypleus tridentatus, Tachypleus gigas, Limulus polyphemus, and Carcinoscorpius rotundicauda, were comparatively studied on their biochemical and immunological characteristics. Each coagulogen had a molecular weight of about 20,000 by sodium dodecyl sulfate‐gel electrophoresis. The clotting enzyme of T. tridentatus could cause the gelation of the coagulogen not only from the species but also from other three species. Having analogous function in the clotting mechanism and the same value of molecular weight, only coagulogen of L. polyphemus was immunologically very different from that of others.
Role of subdermal current shunts in the failure of frogs to regenerate
Authors: Borgens Richard B. , Vanable Joseph W. , Jaffe Lionel F.
Published: June 2005

Large, uniform, skin‐driven currents (20–40 μamp/cm2) leave the ends of limb stumps of post‐metamorphic frogs (Rana pipiens) from about the first through the tenth day after amputation. However, right after amputation, while currents of comparable density may leave the periphery of the cut surface, current densities are greatly depressed in the center of this surface. We suggest that this depression is brought about by shunting through the subdermal lymph space (characteristic of anurans but not urodeles); continues in covert form after formation of a wound epithelium; and helps explain the ability of small, imposed currents to initiate frog limb regeneration.
The influence of acclimation temperature on the phospholipid metabolism of an aquatic crustacea (Carcinus maenas)
Authors: Chapelle Serge , Zwingelstein Georges , Meister Roger , Brichon Gérard
Published: June 2005

Incorporation of 32P into phospholipids from gills, hepatopancreas and muscle isolated from the crab Carcinus maenas was analysed at acclimation temperatures of 7°C and 27°C. Velocity of total phospholipid labelling from inorganic phosphate (Pi) and acid‐soluble organic phosphate (PoAS) rose with an increase in environmental temperature. The velocity of biosynthesis of certain phosphatides was especially altered by thermal stress. The velocity of 32P incorporation into PA was increased at lower temperature (7°C), whereas the turn‐over of other phospholipids (particularly PC and SPH) was relatively low at the same temperature.

In general, the warm acclimation produced, in all tissues, an increased rate of 32P incorporation into PC and SPH accompanied with a negligible modification of the label entry into PE. It is suggested that the activity of the 32Pi → 32PA → 32PI pathway is increased at high temperature in gills and hepatopancreas and that the activity of LPC ⇄ PC deacylation‐acylation reaction in hepatopancreas depends on the temperature of the exterior medium.
Separation of calcium effects on motility and zona binding ability in mouse spermatozoa
Authors: Heffner Linda J. , Sailing Patricia M. , Storey Bayard T.
Published: June 2005

The ionic specificity of Ca+2 requirements for binding to the zona pellucida and maintenance of motility were studied in mouse gametes by comparing the effects of four cations: Ca+2, Sr+2, La+3, and spermine cation (Sp+4). Cumulus‐free mouse eggs were inseminated in vitro with sperm which had been preincubated for 60 min in Tris‐NaCl buffer containing one or more of the above cations. Motility was assessed microscopically and zona binding, by the stop‐fix technique, utilizing centrifugation through a discontinuous density gradient. The sperm were motile upon release from the epididymis, and all sperm maintained their motility in complete culture medium. Sperm incubated in Tris‐NaCl buffer differed in motility among samples as follows: The majority of sperm samples remained motile in Tris‐NaCl containing 1.7 mM Ca+2, but lost motility if Ca+2 was absent. The remaining samples could be divided into two populations: those which maintained motility in the absence of Ca+2. Support of Zona binding required Ca+2 in all samples examined. Equimolar Sr+2 could substitute for Ca+2 in maintaining motility but not in supporting binding. Sp+4and La+3 did not support motility. If Sr+2 were present to maintain motility, both Sp+4 and La+3 supported binding as well as Ca+2. Sr+2 did not complete with any of the other cations for support of zona binding. Ca+2 and Sp+4 together in the medium produced a synergism in the number of sperm bound. La+3 would substitute for Ca+2 in this synergism. These results demonstrate for the first time that mouse sperm have Ca+2 requirement for the motility maintenance and that binding to the zona and maintenance of motility are two different Ca+2‐dependent processes whose active sites can be distinguished by cation substitution.
Yolk proteins in developing follicles of the house cricket, Acheta domesticus (L.)
Authors: Nicolaro Mary‐Lou , Bradley James T.
Published: June 2005

The occurence of the two major yolk proteins in vitellogenic follicles at various stages of development in the house cricket, Acheta domesticus, was studied electrophoretically. Follicles were staged into size classes ranging from 0.75 mm (stage I) to ≥2.0 mm (stage IV) for unfertilized eggs (chorionated follicles) and the molar ratio of the two vitellins within follicles of each stage determined. The ratio of vitellin I to vitellin II during the early stages of vitellogenesis was found to be greater than that during later stages, suggesting the possibility of changing selectivity of vitellogenin uptake by follicles as they progress through the vitellogenic phases of oogensis. The relative distribution of vitellins I and II within the cytoplasm of unfertilized, chorionated follicles was studied by sectioning stage IV follicles into thirds and determining the molar ration of vitellin I to II in each third. It was found that a differential distribution of each vitellin is established during oogenesis such that vitellin I is present in greater quantities in the posterior region and vitellin II in greater quantities in the anterior region of the follicle.

The molecular weights of the two vitellins were estimated using native polyacrylamide gels of varying percents acrylamide. The molecular weights of vitellins I and II were estimated at 352,000 and 327,000 daltons, respectively.
Regeneration of rabbit ear tissue
Authors: Williams‐Boyce Patsy K. , Daniel Joseph C.
Published: June 2005

Holes punched in the ears of rabbits are repaired by regeneration of new tissues from blastemas found on the periphery of the wounds. The proportion which successfully regenerated was greater in males than in females (75% vs 20%), in pregnancy than during estrus or lactation (75% vs 25%), and in ovariectomized does given testosterone than in those given oil carrier alone (88% vs 50%), but the speed of closure did not differ in these groups. The steroid hormone influence postulated by other workers is confirmed.

Closure was faster in younger animals and for second holes punched on the same site where earlier holes had been repaired, in both cases, by shortening of the initial seven to ten day delay period seen for primary holes in adult ears. The cartilage layer was also thicker after regeneration from secondary punches and the success rate greater (67% vs 29%). These observations suggest a “priming” effect on the tissue from the primary punch.

Ear holes in the area proximal to the head were repaired faster and with more success (78% vs 12% ) than those punched distally. The relative thickness of the cartilage layer may be the critical factor. Tissues did not regenerate from semicircular wounds made on the edge of the pinna.

Hair grown on regenerated ear skin reestablished the original color pattern. Skin regenerating for holes punched where skin from the back had been transplanted to ears had the characteristics of back skin, but no regeneration was detectable from transplanted toe tissue. Skin from other locations can regenerate in the environment provided by the ear but more complex tissue structure put into the same location apparently cannot. Skin cells involved in regeneration originate from the tissues bounding the wound.
A study of the catalytic properties of pyruvate kinase isozymes from salmon and an examination of their functional relationships
Authors: Guderley Helga , Cardenas Janet M.
Published: June 2005

Two major isozymes of pyruvate kinase that differ in electrophoretic and kinetic properties are found in salmon (Oncorhynchus kisutch). Type M occurs in cardiac and skeletal muscle, while type K is the main isozyme of the other tissues. We have been examining the structural and kinetic properties of the pyruvate kinase isozymes of salmon in an effort to assess their regulatory properties as well as their structural and functional relationships to the isozymes from “higher” vertebrates. We find that type K pyruvate kinase has hyperbolic kinetics with both phosphoenolpyruvate and ADP but that the apparent affinities for the two substrates are interdependent. That is, decreased affinities for phosphoenolpyruvate occur at higher concentrations of ADP and vice versa. In contrast, salmon type M pyruvate kinase has slightly sigmoidal kinetics with phosphoenolpyruvate, indicative of cooperative interactions among subunits of the latter isozyme. However, the affinity of this isozyme for each substrate is much less effected by the concentration of the other substrate. Salmon type K pyruvate kinase binds Mg++ cooperatively in the absence of fructose bisphosphate, where as type M binds Mg++ twice as tightly but in a non cooperative fashion. Both enzymes are inhibited to a similar extent by ATP, but they may differ in the nature of this inhibition. The salmon isozymes differ from avian and mammalian pyruvate kinase in that they are much less susceptible to inhibition by alanine and phenylalanine. The kinetic properties of salmon type K pyruvate kinase imply it to be more amenable to regulation that salmon type M, a situation that is also true for the corresponding isozymes from birds and mammals. Nevertheless, the two salmon isozymes appear to be more similar kinetically to each other than are types K and M pyruvate kinases from higher vertebrates, suggesting less evolutionary divergence for the salmon isozymes.
Genetic variability of alcohol dehydrogenase among Australian Drosophila species: Correlation of ADH biochemical phenotype with ethanol resource utilization
Authors: Holmes Roger S. , Moxon Leith N. , Parsons Peter A.
Published: June 2005

Alcohol dehydrogenase (ADH) activities, electrophoretic phenotypes, and the extent of ethanol resource utilization are compared for three groups of species distinguishable on ecological criteria: 1) the cosmopolitan species D. melanogaster, a frequent inhabitant of wineries; 2) fruit‐baited species of the typically Australian subgenus Scaptodrosophila: D. lativittata, D. nitidithorax and D. howensis; and 3) Scaptodrosophila species not attracted to fermented‐fruit baits being collected by sweeping in temperate rain forests (D. inornata, D. collessi) or from Hibiscus flowers (D. hibisci). D. melanogaster showed the highest levels of ADH activity and an electrophoretic polymorphism with two active allelic forms, while group 2) species showed intermediate ADH activities and polymorphisms, which were consistent with “high activity” and “low activity” allelic forms in natural populations of these species, and group 3) species showed only “low activity” forms. Ethanol resource utilization follows the same sequence, being 1 > 2 > 3(D. howensis and D. collessi were not tested). Therefore the species considered shown an association of ADH biochemical phenotype, laboratory ethanol utilization, and resources utilized.
Effects of the gene Wh on reproduction in the Syrian hamster, Mesocricetus auratus
Authors: James Susan C. , Hooper Gary , Asher James H.
Published: June 2005

The gene Wh, causing anophthalmia in the Syrian hamster, Mesocricetus auratus, is a highly pleiotropic gene, which has profound effects upon eye development, pigmentation, and reproduction. Since male hamsters homozygous for this gene are usually sterile, the objective of this study was to determine whether the testes of mutant hamsters differed from the normal phenotype. Accordingly, the testicular tissue from ten normal, ten heterozygous, and ten homozygous mutant animals in the AN/As‐Wh strain were compared at the gross, light, and electron microscopic level. Testicular tissue from several mutant animals approached the normal phenotype, due to variable expression of the gene. However, most testes from homozygous mutant hamsters were hypoplastic and aspermic. Abnormalities were observed in Leydig cells, Sertoli cells, and in the developing germ cells. Seminiferous tubules contained germinal epithelium arrested in the early spermatid stage of spermiogenesis, possibly due to premature failure of the Golgi apparatus and a subsequent dysgenesis of the acrosome. Since the primary action of the gene is unknown, it was postulated that the gene either acts directly to alter pituitary function, or that the abnormalities in reproduction are due to a failure of eye development and subsequent lack of function of the visual pathway.
External ultrastructure and function of the “spiculum copulatus” (SC) of the German cockroach, Blattella germanica (L.) (Dictyoptera:Blattellidae)
Authors: Ramaswamy S. B. , Gupta A. P. , Fowler H. G.
Published: June 2005

Studies were undertaken to determine the ultrastructure and function of the spiculum copulatus (SC) on the seventh abdominal tergum of adult male Blattella germanica (L.).

The SC is located on the seventh abdominal tergum in between the anterior pair of tergal gland orifices. It is approximately 250 μm long and 40 μm in diameter at the base. It is invested with numerous sensilla, many of which are bifurcate and trifurcate. Cauterization of the SC leads to cessation of certain phases of the male precopulatory behavior (such as extension and arching of the abdomen and clamping of the genitalia), thereby preventing mating. The cauterization studies indicate that the SC and its sensilla possibly serve a mechanoreceptive function.
An experimental analysis of the role of bottle cells and the deep marginal zone in gastrulation of Xenopus laevis
Authors: Keller R. E.
Published: June 2005

Earlier work suggested that the change in shape or the active migration of the bottle cells in the amphibian blastoporal region results in an invagination that comprises a major part of gastrulation. In the present study of gastrulation in Xenopus laevis, microsurgical extirpation and rearrangement experiments, analyzed with time‐lapse cinemicrography and scanning electron microscopy, show that the bottle cells have a lesser role in gastrulation. Gastrulation is not a process of invagination but of involution of the deep and superficial layers of the marginal zone. Involution is dependent on unique properties of the cells in the deep marginal zone. In contrast, the superficial layer, including the bottle cells, does not have properties essential for involution but is passively moved inside to form the lining of the archenteron by what is probably an active migration of the underlying cells of the deep marginal zone. Bottle cells form by the shrinking and thickening of the superficial layer in the late blastula and early gastrula. They are moved inside, largely because of their attachment to the underlying deep cells, and then they spread and flatten in the latter half of gastrulation to form a large area of the lining of the periphery of the archenteron. The formation of the initial blastoporal groove by bending of the superficial cell sheet during bottle cell formation and the extension of the periphery of the archenteron during spreading of the bottle cells is the extent of the active contribution of bottle cells to the depth of the archenteron. The bulk of the depth is generated by the vegetal extension of the marginal zone and the movement of the involuted deep cells toward the animal pole.
Characterization of the female sterile (1) 1304 mutant of Drosophila melanogaster: Pattern of RNA metabolism in the ovary
Authors: Mulligan Pamela Khipple
Published: June 2005

The female sterile mutant of Drosophila melanogaster, fs(1)1304 (1‐19 ± 2), has been characterized. Our studies show that the mutation affects the organization of nucleolar material in the ovarian nurse cells and the pattern of RNA metabolism in the ovary. Autoradiographic analysis of incorporation of 3JH‐uridine in vivo and analysis of 3H‐uridine incorporation into high molecular weight RNA in vitro suggest that RNA from the ovaries of homozygous fs flies is degraded at a higher rate than that from heterozygous fs and wild‐type ovaries. It is likely that the RNA class affected is ribosomal RNA. These data are discussed in the context of the functional role for the wild‐type gene allelic to fs(1)1304, and it is suggested that one of the effects of the mutation may be on the biogenesis of ribosomes that are to be stored in the oocyte.
Concerning the primary defect leading to the pleiotropic effects caused by anophthalmic white (Wh) in the Syrian hamster Mesocricetus auratus
Authors: Asher James H.
Published: June 2005

Ten physiological parameters, controlled by the pituitary‐hypo‐thalamic axis, were measured upon males of three genotypes: whwh (cream), Whwh (black eyed white) and WhWh (Anophthalmic white). Univariate analyses of variance comparing data from these hamsters indicated that the gene significantly affects six of these physiological parameters. A principal component and correlation analysis using the multivariate data indicated that of these 10 parameters, six were linearly independent and five were significantly altered by the action of the gene Wh.

The results of these analyses and those previously reported suggest that the gene Wh alters the development of the embryonic diencephalon which, in turn, alters the development of the eye and pituitary leading to significant affects on the physiological parameters measured. A new method is described which should, in general, permit the determination of the primary action of a gene in the case of highly pleiotropic mutants.
Asexual reproduction and regeneration properties of a nonbudding mutant of Hydra viridis
Authors: Novak Patricia L. , Lenhoff Howard M.
Published: June 2005

A nonbudding mutant of Hydra viridis reproduced asexually in an atypical but unique manner in terms of morphogenesis and rate of hydranth formation. It sprouted tentacles randomly along the body column at a distinct distance from the head end of the animal. These tentacles then clustered and a hypostome formed at the center of the cluster. Asexual reproduction by the mutant was disorganized and slow. A single mutant was able to produce an average of only 10 hydranths in two months as compared to the wild type which can produce as many as 1010 hydra during that same period. Both the apical and basal portions of a bisected nonbudding mutant regenerated atypically. Unlike wild type hydra, the cut apical portion formed a second head at the regenerating end if the transection was made at least 2 mm away from the original head. The basal portion of a transected mutant regenerated a head and formed supernumerary tentacles along its body column. Bipolar mutants with both heads decapitated sprouted supernumerary tentacles along their midbody column. Tentacle sprouting in these bipolar mutants did not develop within 1.7 ± 0.4 mm of the newly regenerated heads. This distance is similar to that (1.9 ± 0.1 mm) existing between the head and the budding region in wild type hydra. The number of supernumerary tentacles sprouted was proportional to the original length of the bipolar mutant.
Fluorescent observations on the stress fiber system of neural crest cells after con a treatment. A simple, quick, fluorescent method
Authors: Moran Denis
Published: June 2005

Concanavalin A (Con A), 25 μg/ml in the tetrameric form, inhibits migration and differentiation of cultured amphibian neural crest. Affected cells loose their angulated morphology and become rounded. A correlation exists between the lectin treatment and the overall cellular and stress fiber morphology. We describe a quick, simple method for disclosing the stress fiber system using fluorescence microscopy after staining with 1% alcoholic eosin.
Cytokinesis: Cleavage furrow establishment in cylindrical sand dollar eggs
Authors: Rappaport R.
Published: June 2005

By confining fertilized, denuded sand dollar (Echinarachnius parma) eggs in short lengths of capillary tubing so that they were reshaped into elongate cylinders it was possible to control the orientation of both the mitotic apparatus and the subsequent cleavage furrow as well as the distance from the mitotic apparatus to the cylindrical cell surface. The technique left the polar regions accessible to experimentation and was used before first and second cleavages.

The time when the equatorial surface becomes capable of forming a complete, permanent furrow which can function independently of the mitotic apparatus was determined by aspirating the mitotic apparatus from one of a pair of cylindrical cells at second cleavage and timing the interval between the operation and the appearance of the furrow in the control cell. When the mitotic apparatus is removed 4 minutes or less before control furrowing, the operated cell cleaves, but when the same operation is accomplished 5 minutes or more before control division, furrows do not appear in the operated cell. The results imply that the necessary interaction between the mitotic apparatus and the surface is not completed until 4 minutes before the furrow initiates function, and that thereafter the mitotic apparatus is dispensable. The distance between astral centers and the extent of their radiate structure continue growing after the position of the furrow is established.

Experiments performed before the mitotic apparatus becomes dispensable, during the period of its interaction with the surface, revealed that agitation of the poles by vibration and repeated manipulation did not interfere with division when imposed continuously until the furrow appeared. Changing the shape of the poles did not affect cleavage; neither did aspiration of polar cytoplasm and polar portions of asters before both first and second cleavage. Cleavage also occurred despite sequestration of the polar portions of both asters in large‐bore pipettes. Repeated skewering of the mitotic apparatus along the length of its midline often altered its appearance but did not prevent division.
The roles of Ca and Mg in starfish oocyte maturation induced by 1‐methyladenine
Authors: Rosenberg Michael P. , Lee Harold H.
Published: June 2005

The ovarian hormone 1‐methyladenine (1‐MA) stimulates fully grown starfish oocytes to undergo germinal vesicle breakdown (GVB). Patiria miniata oocytes treated with 10−6 M 1‐MA underwent GVB by 45 minutes of treatment. However, in the absence of extracellular Ca++ GVB was delayed, with maximum GVB occuring at 180 minutes of treatment. Both the rate and amount of3 H‐1‐MA bound were depressed in the absence of extracellular Ca++ Reflecting this decrease in hormone binding, the minimum time oocytes in CaFSW needed to be exposed to the hormone was increased from 12 to 35 minutes. Direct measurement of total cellular Ca concentrations during 1‐MA‐induced maturation revealed an increase in Ca levels by 30 minutes posttreatment, followed by a decrease to initial level by 60 minutes. In the absence of extracellular Mg++, oocytes treated with 1‐MA did not undergo GVB. However, binding of the hormone was not dependent on extracellular Mg++. Total cellular Mg concentrations were found to increase to maximum levels by 10 minutes of hormone treatment, and to decrease to basal levels after 30 minutes. Our data suggest that free‐diffusable Mg++ was necessary for hormone action during the critical hormone‐dependent period, while extracellular Ca++ was important for hormone binding. Furthermore, we interpret our data to indicate that 1‐MA regulates oocyte permeability to Ca and Mg during oocyte maturation.