bluuebunny/crossref_metadata_2025_split huggingface dataset:
Continuous recording of erythrophore membrane potential during change of stage in Ocypode pallidula (Crustacea)
Authors: Hayashi J. H. , Cooke I. M. 
Published: June 2005

AbstractIntracellular recordings of membrane potential were obtained from the central region of Erythrophore of the ghost crab (Ocypode pallidula) in all stages of aggregation. Stable membrane potentials were recorded from 58 cells. The potential was unrelated to stage. The average value was −59.0 ± 5.86 mV; the mode was −60 mV. The mode analyzed by stage was also −60mV. Fourteen erythrophores were continuously recorded during one or more complete cycles of aggregation, in response to erythrophore concentrating hormone (applied as an eyestalk extract), and subsequent reexpansion during continued saline perfusion. Membrane potential varied by less than 3 mV from its initial value and did so in a random manner. Injection of hyperpolarizing or depolarizing currents of up to 10−8 A for periods as long as ten minutes caused no visible responses. Current‐voltage relations, observed for six cells, were linear over the range tested (± 20 mV) and provided estimates of input resistance which averaged 18 megohms. A marked increase in electrode voltage noise, from less than 0.5 mV to as much as 2 mV, upon penetration of chromatophores was consistently observed. Changes of membrane potential are not involved in the responses of erythrophores to neurohormones nor associated with migration of pigment granules. Membrane potentials do not vary with the state of aggregation of these cells.
Immunological specificity of anti‐zona binding to zona pellucida
Authors: Sacco Anthony G. 
Published: June 2005

AbstractBiochemically purified and F(ab′)2 immunoglobulin fractions were prepared from several antisera, including a human serum, which contained anti‐zona pellucida activity. Antizona activity was monitored either by the formation of the antibody produced precipitation layer on the zona following antiserum treatment and/or by the indirect fluorescent antibody method. No changes in anti‐zona activity were observed when the purified and the digested immunoglobulin preparations from each antiserum were compared to their whole serum counterparts. It is concluded that anti‐zona binding to the zona as well as the formation of the precipitation layer on the zona is the result of a specific antigen antibody reaction.
The survival of embryos of the annual fish Nothobranchius guentheri exposed to temperature extremes and the subsequent effects on embryonic Diapause
Authors: Matias Jonathan R. , Markofsky Jules 
Published: June 2005

AbstractNothobranchius guentheri is an East African annual fish found in temporary bodies of water in areas of alternating rainy and dry seasons. During the dry season the embryos may be exposed to temperature extremes. Embryos have been reported to undergo diapause (developmental arrest), and are thus able to withstand the variable durations of the dry seasons. Since the embryos appear to endure long durations in diapause, and since in diapause they may be exposed to large variations in temperature, we have attempted to determine the thermal tolerance and responsiveness of embryos at diapause and at stages exclusive of diapause. Embryos were exposed to temperatures ranging from −8‐40°C for variable durations of time, and survival, abnormalities and developmental rates determined. Both Diapause I and Diapause II embryos were much less sensitive to temperature extremes than were the other stages, and Diapause II was much less sensitive than Diapause I. Abnormalities only occurred under certain temperature exposures but showed the highest frequency at the early stages of development. Short exposure of Diapause I embryos to −8 and 3.4°C eliminated Diapause II, while short exposure to 40°C enhanced its duration. Although it has been proposed that the onset and duration of the diapauses are denendent on the oxygen concentration of the water, we propose that temper ature may also be another imposrant factor.
Oxygen affinity of the hemolymph of the mesopelagic mysidacean Gnathophausia ingens
Authors: Freel Robert W. 
Published: June 2005

AbstractThe absorption spectrum of hemolymph from the mesopelagic mysidacean Gnathophausia ingens indicates the presence of a hemocyanin. Oxygen equilibrium curves of G. ingens hemolymph demonstrate an unusually high affinity for oxygen which may be physiologically significant for this aerobic, permanent resident of the oxygen minimum layer.
Intra‐ and interspecific transplantation of limb buds in crustacea: A new method for studying central and peripheral interactions in crustacean limbs
Authors: Trinkaus‐Randall V. , Mittenthal J. E. 
Published: June 2005

AbstractLimb buds can be transplanted intra‐ and interspecifically in the fiddler crabs, Uca pugnax and Uca pugilator. These two species differ morphologically, behaviorally, and physiologically. This technique provides a method for examining the relative roles of host and donor tissues in studies of morphology and behavior.
Proteolytic degradation of protamine during thiol‐induced nuclear decondensation in rabbit spermatozoa
Authors: Chang T. S. K. , Zirkin Barry R. 
Published: June 2005

AbstractRabbit sperm nuclei decondensed when incubated with dithiothreitol and Triton X‐100. Protamine isolated from these nuclei during the course of treatment exhibited marked and progressive degradation. Timed interval experiments revealed that the degradation of protamine significantly preceded sperm nuclear decondensation and reached its maximum extent before decondensation was completed. Studies with protease inhibitors demonstrated that proteolysis was involved in both nuclear decondensation and protamine degradation.
Trypsinization increases lectin‐induced agglutinability of uncapacitated guinea pig sperm
Authors: Talbot Prudence , Franklin L. E. 
Published: June 2005

AbstractCapacitated guinea pig sperm are more agglutinable by the lectin soybean agglutinin (SBA) than uncapacitated sperm (Talbot and Franklin, ′78). This study demonstrates that uncapacitated guinea pig sperm become as agglutinable by SBA as capacitated sperm when treated with trypsin, but not chymotrypsin. The pattern of lectin induced sperm agglutination after trypsinization resembles that for capacitated sperm. Also, trypsinization specifically increases SBA induced agglutination and does not affect agglutination by RCA‐60; similar results are obtained during in vitro capacitation. Taken together, these data may indicate that a trypsin‐like enzyme modifies the sperm surface during capacitation.
A large‐scale laboratory maintenance system for gravid purple sea urchins (Strongylocentrotus purpuratus)
Authors: Leahy Patrick S. , Tutschulte Theodore C. , Britten Roy J. , Davidson Eric H. 
Published: June 2005

AbstractA large‐scale laboratory facility for the maintenance of several thousand gravid sea urchins (S. purpuratus) is described. Gametes of this species provide an important research resource for studies of animal development. Methods are described for culturing adult S. purpuratus for periods up to two years or more with almost no mortality after the first three to four weeks following collection. Adult females can be maintained in a fertile state in the culture system for four to six months. When spawned, gravid females living in the culture facility will routinely regenerate normal sized populations of fertile oocytes at 1 to 2‐month intervals. Such females can be used repeatedly as a source of mature gametes for laboratory research. The reproductive performance of these females can be predicted approximately by the number of late vitellogenic oocytes present in their ovaries. After several months the pool of these oocytes is exhausted and no further mature oocytes can be found for a long period. We show, however, that such females are able to carry out a complete annual cycle of oogenesis if held for a long enough period of time in the culture system.
Gradients of proliferation of ciliary basal bodies and the determination of the position of the oral primordium in Tetrahymena
Authors: Kaczanowski Andrzej 
Published: June 2005

AbstractThe pattern of proliferation of new basal bodies in ciliary rows (somatic proliferation) in Tetrahymena was observed. Starved and refed cells were used, because proliferation in these cells is more pronounced than that under other circumstances. The formation of new basal bodies is locally determined by the position of “old” pre‐existing basal body (short range determination). However, the probability of proliferation associated with any given “old” basal body differs very much. This probability is determined by the spatial coordinates of the particular region of the cell (long range determination); however some randomness in this process was also observed. Two different gradients of proliferation were found. The first gradient is circumferential with a maximum number of new basal bodies added in ciliary rows n, 1, 2 and 3 and the minimum number added in ciliary rows 7, 8 and 9. The second is an antero‐posterior gradient with the highest number of new basal bodies added in the midbody region. Moreover, at least in some cases, new oral primordia first appear, as a random proliferation of new basal bodies adjacent to a few old cilia of ciliary row No. 1, resembling somatic proliferation. Then, 2, 3 or even more clumps of basal bodies appear, each having one old cilium posteriorly. These clumps, however, are not linear groups within the ciliary row but instead they form small fields of basal bodies. These findings suggest, that the same two‐gradient system for new basal body addition operates during somatic proliferation and also determines the position of the new oral primordium as the site of the highest gradient value at the intersection of two gradients.
Electron microscopic observation on sperm penetration and pronuclear formation in the fish egg
Authors: Iwamatsu T. , Ohta T. 
Published: June 2005

AbstractUnfertilized eggs of the medaka, Oryzias latipes were inseminated after being mechanically freed from the chorion. In the first step of penetration, as soon as it reached the vitelline surface, the whole spermatozoon was quickly enclosed by ooplasmic protrusions (fertilization cone) of the vitelline surface. In the second step, the egg plasma membrane fused with various regions of the plasma membrane of the enclosed spermatozoon; finally the sperm flagellum was also incorporated into the ooplasm. Initial disappearance of the nuclear envelope of the sperm with vesiculation at the apical region of the head is followed by dispersal of the sperm chromatin. The nuclear envelope is then reformed by fusion of elongated or flattened vesicles along the margin of dispersing nuclear chromatin. The mature male pronucleus has a large nucleolus within a wrinkled envelope. It seems that the fertilization process in this fish involves some features of that occurring in the marine invertebrate and the mammalian eggs.
Dynamics of pigment pattern formation in the zebrafish, Brachydanio rerio. I. Establishment and regulation of the lateral line melanophore stripe during the first eight days of development
Authors: Milos Nadine , Dingle Allan D. 
Published: June 2005

AbstractThe formation and regulation of the larval lateral line melanophore band of Brachydanio rerio was investigated. It is comprised of about 30 melanophores linearly arranged along the horizontal skeletogenous septum. This stripe forms in two distinct stages, an initial migration and orientation of pigment cells which outlines the stripe, and a later round of melanophore differentiation which regulates and perfects the stripe. From the initial melanocyte population which appears between approximately 24 to 48 hours of development and spreads ventrally over the body, some (0–21) melanocytes migrate to and reorient into the horizontal skeletogenous septum. At day 3 this initial lateral line stripe varies in melanophore number between individuals and even between left and right sides of the same embryo. By eight days of age however the lateral line bands of different fish are more uniform in appearance due to the entry of a second wave of melanophores which appear between days 4 and 8.Some observations suggested the operation of a cell territorial‐regulating mechanism. Second round melanophores tend not to appear in somite areas already occupied by 3‐day cells but invariably appear in unoccupied locations. We propose that some “exclusion principle” operates in this embryonic cell population, controlling the positions along the stripe where second wave melanophores can appear.
Dynamics of pigment pattern formation in the zebrafish, Brachydanio rerio. II. Lability of lateral line stripe formation and regulation of pattern defects
Authors: Milos Nadine , Dingle Allan D. 
Published: June 2005

AbstractThe operation of a pigment cell “exclusion principle” during establishment of the lateral line melanophore band was investigated in the zebrafish, Brachydanio rerio. Counts were made of second round melanophores appearing in the horizontal skeletegenous septum in the area bounded by somite No. 11. An average of 1.6 second round melanophores developed in that somite by day 8 when it was initially unoccupied, but when a first wave melanophore was already established in somite No. 11, the value dropped to only 0.2 second round cells per fish. Analysis of the entire lateral line stripe of many fish revealed that second round melanophore exclusion increases with increasing density of 3‐day (first wave) melanophores.Lability of second round melanophore appearance was tested by creating both small and large defects in the 3‐day stripe. Following extirpation of first wave melanophores from somite No. 11, the appearance of 1.6 (average) second round melanophores per fish re‐established total counts equivalent to controls (1.7). This capacity for numerical regulation was further tested by destroying all first wave melanophores in the stripe. Second round melanophore development restored the stripe to approximately 90% of control values.Second wave melanophore appearance in this stripe is therefore labile; the process is subject to “exclusion” by first wave cells and is capable of repairing perceived defects such that numerical pattern regulation occurs.
Estimation of cell size and DNA content in fossil fishes and amphibians
Authors: Thomson Keith Stewart , Muraszko Karin 
Published: June 2005

AbstractGenome size (cellular DNA contents) in living and fossil amphibians and their ancestors among the fossil lobe‐finned fishes are estimated indirectly through measurement of cell size, following procedures previously established in a study of evolutionary changes in the genome size of lungfishes. It is concluded that large DNA contents per cell arose several times independently within the Amphibia; that the ancestral lobe‐finned fishes and the early amphibians and reptiles all had small cell size and low DNA contents (5 –10 pg/nucleus). There is no evidence that an increase in genome size is a causal factor in major evolutionary change, rather it occurs in the end members of lineages.
Temperature dependence of sperm‐egg fusion and post‐fusion events in hamster fertilization
Authors: Hirao Y. , Yanagimachi R. 
Published: June 2005

AbstractThe effects of temperature (4–37°C) on sperm‐egg fusion and the post‐fusion events were studied. At 4–10°C, acrosome‐reacted spermatozoa bound to egg plasma membranes, but could not fuse with them. At 25°C or above, both binding and fusion took place. The post‐fusion events could occur over a broad temperature range (4–37°C) but the events progressed faster with increasing temperature. An abnormal development of egg pronucleus, possibly due to an incomplete functioning of the meiotic spindle mechanism, was observed in eggs inseminated at 37°C and cultured at 25°C.
Increase in concanavalin a binding sites in mouse blastocysts during implantation
Authors: Wu J. T. , Chang M. C. 
Published: June 2005

AbstractThe number of concanavalin A (Con A) binding sites were determined in mouse blastocysts before and during implantation. In intact pregnant mice (Day 1 = day of finding vaginal plug), the Con A binding sites per blastocyst were increased from 169 million on Day 4 morning to 1160 million on Day 5 morning when implantation was under way. In pregnant mice ovariectomized on Day 3 and treated daily with 1 mg progesterone, the Con A binding sites per blastocyst on Day 9 (inactive) were 363 million; if the mice had received an additional injection of estradiol 24 hours earlier to induce implantation, the Con A binding sites were increased to 1211 millions. Thus, a more than twofold increase in the Con A binding sites occurs in the mouse blastocyst during implantation.
Expression of an onco‐developmental antigen among avian species
Authors: Dietert Rodney R. , Sanders Bob G. 
Published: June 2005

AbstractRabbit antisera directed against an onco‐developmental antigen on chicken red blood cells have been serologically dissected through specific adsorptions. It is now possible to detect 13 antigenic determinants with the fractionated antisera. The onco‐developmental antigen referred to as chicken fetal‐leukemic antigen (CFA) is fetal‐specific in the white Leghorn chicken, being present on the embryonic but not adult peripheral red blood cells of nonleukemic birds. However, one or more of the onco‐developmental antigenic determinants have been detected on adult peripheral red blood cells of non‐Gallus avian species, as well as on red blood cells from two adult chicken varieties.For phylogenetic purposes, red blood cells from avian species were characterized for their combinations of CFA determinants. Comparisons among species revealed specific patterns of antigenic expression within phylogenetic groups. Several CFA determinants were restricted in their occurrence to species within a single family, and one determinant was found in all cases where CFA was expressed. The distribution of CFA determinants was used to determine immunological distances among four Galliform species. These distances agreed with the immunological relationships established using different serological markers.
Further investigations on the prelethal effects of the killing action of kappa containing killer stocks of Paramecium aurelia
Authors: Jurand A. , Preer J. R. , Rudman B. M. 
Published: June 2005

AbstractKappa symbionts of two stocks of Paramecium aurelia were isolated and their killing activity tested on sensitive paramecia. The symbionts from stock 51, which is a hump killer, induce sensitive animals to cease the formation of food vacuoles due to changes at the bottom of the buccal cavity in the food vacuole forming area (the naked ribbed wall). Instead of normal food vacuoles only narrow elongated outpocketings are formed. Food vacuoles which have been formed during treatment contain kappa symbionts. After disintegration due to digestion of the symbiont cells the R bodies unwind and penetrate the food vacuole membranes. Food vacuoles disintegrate so that their contents (food bacteria) are found surrounded by the cytoplasm. Later there are present uncoiled R bodies in the cytoplasm and cytoplasmic blebs on the surface of the pellicle. At the same time affected paramecia become less motile, most probably due to the occlusion of cilia by the folds formed by the blebs round them and eventually by penetration of the cytoplasm into the cilia themselves. After prolonged treatment there are great accumulations of lipid droplets in the cytoplasm of sensitive animals.Kappa symbionts from the vacuolizing stock 562 cause rather similar prelethal symptoms. In addition, these kappa symbionts induce the macronuclei in sensitive paramecia to become spherical instead of elongated, their contents somewhat optically denser and the macronuclear envelope less discernible. Secondly, mitochondria undergo very noticeable necrotic changes in the case of treatment with stock 562 kappa symbionts and also to a lesser extent in stock 51. Furthermore, kappa toxin of stock 562 causes deciliation of affected sensitive paramecia and in later stages lipid droplets accumulate in the cytoplasm.It is suggested that the primary target of kappa toxins of both stocks are the biological membranes in various subcellular structures of sensitive paramecia.
“Malic” enzyme, fumarate reductase and transhydrogenase systems in the mitochondria of adult Spirometra mansonoides (Cestoda)
Authors: Fioravanti Carmen F. , Saz Howard J. 
Published: June 2005

Abstract“Malic” enzyme and fumarate reductase activities have been demonstrated and partially characterized in mitochondria from the adult cestode Spirometra mansonoides. The former enzyme requires Mn++ and NAD+ for optimal activity, but also couples with NADP+ at approximately 60% of the rate observed with NAD+. The mitochondrial membrane bound fumarate reductase is of particular interest since activities have been obtained at comparable rates with either NADH or NADPH as electron donor. Intact Spirometra mitochondria catalyze an anaerobic, malate dependent, electron transport associated uptake of inorganic 32P into organic phosphate.Spirometra mitochondria also exhibit three transhydrogenase activities. NADH:NAD+, 4 NADPH:NAD+ and NADH:NADP+ transhydrogenases are described and possible physiological roles are discussed.
Effect of temperature on post‐activity oxygen consumption in lunged and lungless salamanders
Authors: Feder Martin E. 
Published: June 2005

AbstractTemperate zone lunged, temperate zone lungless, and neotropical lungless salamanders were examined to determine if differences in rates of oxygen consumption (V̇) after vigorous activity are correlated with body temperature and size differences among the three groups. Salamanders were stimulated electrically for two minutes, and V̇ measured for 75 minutes afterwards using Warburg manometers. Slopes of regressions of log maximum V̇ against log body size are greater for lunged salamanders than for lungless salamanders at 5°, 15° and 25°C; differences in slope among groups do not change with temperature. Slopes of log aerobic scope‐log body size regressions are also greater for lunged salamanders than for lungless salamanders, but this difference increases with temperature. Lungless salamanders repay oxygen debt more slowly than lunged salamanders at large body size and high temperatures. Q10's of maximum V̇ and aerobic scope increase less with temperature in lungless salamander species than in lunged salamander species.If differences in V̇ are due to respiratory surface area differences, then lunglessness may restrict post‐activity V̇ at large body size and high temperatures. However, neotropical lungless salamanders live at high temperatures and large sizes, which suggests that high post‐activity V̇ is unnecessary for many salamanders.
Thermal acclimation more extensive for behavioral parameters than for oxygen consumption in the nematode Caenorhabditis elegans
Authors: Dusenbery David B. , Anderson Gary L. , Anderson Elizabeth A. 
Published: June 2005

AbstractThermal acclimation in the free‐living soil nematode, Caenorhabditis elegans was studied by determining effects of both growth and test temperatures on oxygen consumption and behavior. Growth temperature (15, 20, or 25°C) had no significant influence on oxygen consumption in the range 10–30°C, although cold‐grown worms had higher consumption at 5°C. In contrast, measurements of the fraction of worms moving at any instant and of chemotaxic ability both showed nearly complete thermal acclimation (in the sense that activity‐temperature relationships were shifted nearly as much as the differences in growth temperature). Measurements of the rates of acclimation using the behavioral assays indicated acclimation is half complete in about two hours.