bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isolation and separation of cells from the digestive gland epithelium of Busycon canaliculatum
Authors: Cornell‐Bell A. H. , Munro D. R. 
Published: June 2005

AbstractA structural analysis of the intact digestive gland epithelium of Busycon canaliculatum was undertaken at the light and ultrastructual levels. Procedures were developed for the isolation and separation of component epithelial cells by modifying existing pronase digestion techniques. Three distinct cell types were identified following separation by velocity sedimentation. Cells identified after isolation, and separation can be related to the intact digestive gland epithelium.
Mechanisms of G6PD isozyme pattern changes at fertilization
Authors: Barber Mary Lee , Kolan David M. , Yabuta Craig , Nielsen Blake 
Published: June 2005

AbstractThe electrophoretic pattern of G6PD changes in sea urchin egg supernatants, gels, and pellets (homogenized in 0.01 M MgCl2, 0.01 M Tris, pH 8, and centrifuged at 4 × 104g) within the first minute following sperm penetration. Therefore, the changes in pattern are an early event of egg activation and are not changes in gene activity. Calcium ionophore activation causes similar changes in G6PD in unfertilized eggs, so calcium is probably involved directly or indirectly. Treatment with 1 mg/ml of G6P and/or NADP, DTT, or papain also causes changes in the isozyme patterns, but the resulting patterns are different from patterns obtained from the fertilized fractions, and each treatment produces a unique pattern. The results lead to the conclusion that the different patterns of unfertilized and fertilized eggs are due to enzyme posttranslational modification. Different patterns may result from intrinsic differences in (1) —SH reduction or levels of glutathione, (2) substrate and cofactor levels, or (3) proteolytic enzymes released naturally or as a result of homogenization.
Low water vapor conductance of hard‐shelled eggs of the gecko lizards Hemidactylus and Lepidodactylus
Authors: Dunson William A. 
Published: June 2005

AbstractTypical reptilian eggs require a moist substrate for normal development and undergo a water loss across the shell in dry air many times that of avian eggs. Certain geckos lay hard‐shelled, calcareous eggs, often in arboreal locations, that have been postulated to be truly cleidoic. It has been demonstrated here for the first time that such hard‐shelled gecko eggs do in fact have extremely low rates of evaporative water loss in dry air. Indeed, values of water vapor conductance are considerably lower than those predicted for avian eggs of the same mass. Normal embryonic development apparently does not require absorption of liquid water from the environment. It is quite likely that these geckos represent an independent evolution of the cleidoic egg, separate from the reptilian lineage that led to the birds.
Purification and composition of protein antifreezes with high cysteine contents from larvae of the beetle, Tenebrio molitor
Authors: Patterson Jean L. , Duman John G. 
Published: June 2005

AbstractTwo antifreeze proteins with thermal hysteresis activity (they depress the freezing point of aqueous solutions by a noncolligative mechanism well below the melting point) were purified from cold‐acclimated larvae of the beetle, Tenebrio molitor. Both proteins have unusual amino acid compositions consisting of high levels of cysteine (15.4 and 28.0 mol%).
insect vitellins: Identification, purification, and characterization from eight orders
Authors: Harnish Delsworth G. , White Bradley N. 
Published: June 2005

AbstractVitellins were identified, purified, and analyzed from insects representing eight orders. The structures and polypeptide constituents of vitellins of Hyalophora cecropia, Tenebrio molitor, Rhodnius prolixus, Forficula auricularia, Periplaneta americana, and a mayfly were found to have common features. The native proteins had Mr of 385,000–470,000 (385–470 K) and were composed of high (100–180 K) and low (47–84 K) molecular weight polypeptides in equimolar proportions. The vitellins of Apis mellifera, a sphecid wasp, and Aedes aegypti, however, had lower Mr (200–350 K) and were composed of only large polypeptides (170–190 K). The higher Diptera form a distinct third group with vitellins made up entirely of small polypeptides of about 50 K.
Insect vitellins: Identification of primary products of translation
Authors: Harnish Delsworth G. , Wyatt G. R. , White Bradley N. 
Published: June 2005

AbstractThe primary products of translation of the vitellins of Hyalophora cecropia, Tenebrio molitor, and Aedes aegypti were identified by pulse‐chase labeling in fat body incubated in vitro, specific antisera being used to identify the immunospecific products. The vitellogenin of H. cecropia was found to be synthesized as a polypeptide of 220,000 daltons (220 K), which was cleaved to yield two polypeptides of 180 K and 47 K. The immunoprecipitable polypeptides secreted into the media during a 3‐hour culture were also 180 K and 47 K. The vitellogenin of T. molitor was synthesized as 204 K primary translation products, which were cleaved to yield polypeptides of 160 K, 56 K, and 45 K. A. aegypti vitellogenin differed from those H. cecropia and T. molitor in that the protein was synthesized as two closely migrating polypeptides of about 170 K, which were not cleaved prior to secretion. RNA from blood‐fed female A. aegypti directed the synthesis of polypeptides, in the rabbit reticulocyte cell‐free protein synthesizing system, which were of similar weight to the vitellin polypeptides. These results, taken together with data published elsewhere on certain higher Diptera, support the division of insect vitellins into three broad structural groups, as already proposed (Harnish and White, 1982).
Cytodifferentiation in the accessory glands of Tenebrio molitor. VII. Patterns of leucine incorporation by the bean‐shaped glands of males
Authors: Happ George M. , Yuncker Christine , Dailey Patrick J. 
Published: June 2005

AbstractThe bean‐shaped accessory glands of male mealworm beetles are morphologically complex. Seven distinct cell types produce a semisolid secretory mass that contains structural proteins of the spermatophore. Cell numbers increase 3.5‐fold over the pupal instar, and gland volume increases 30‐fold over the pupal and early adult stage. DNA content reaches its maximum at adult ecdysis (11 pg/secretory cell), RNA at 4 days later (55 pg/cell), and protein at 6 days after ecdysis (1,200 pg/cell). Rates of 14C‐ and 3H‐leucine incroporation increase in parallel to the rise in protein content. Over ten putative secretory protein bands were identified by using one‐dimensional SDS‐slab gel electrophoresis to compare BAG homogenates with homogenates of the secretory mass and the spermatophore. At least five of these secretory proteins accumulate in BAGs after adult ecdysis, and most show high rates of leucine incorporation in the adult. Twodimensional gel electrophoresis (pI and SDS) and fluorography allowed us to identify a score of reference spots, at least seven spots that are characteristic of the pupa, and over 40 spots that appear to be differentiation‐specific and are presumably secretory products. The fluorographic indices give an unambiguous means of scoring terminal differentiation in the BAG.
Preconjugant cell interaction in Euplotes crassus: An analysis by temporary cycloheximide treatments
Authors: Dini F. , Miyake A. 
Published: June 2005

AbstractConjugation in ciliates is induced by the interaction between preconjugant cells of complementary mating types. We investigated this interaction in Euplotes crassus by inserting a temporary treatment of 10 μg/ml cycloheximide before and during the interaction. This agent effectively inhibits protein synthesis and reversibly inhibits conjugation in this species. Our results indicate that 1) preconjugants of each mating type have a type‐specific protein factor for the interaction; 2) the factor is in a state of equilibrium of turnover and synthesis; 3) interaction by these factors induces a higher production of the same factors; 4) at the beginning of this interaction, a nonprotein factor, which participates in the preconjugant interaction in a still unspecified way, is produced; and 5) the interaction also transforms the cell surface so that cells can unite in conjugant pairs. Preconjugant interaction of E. crassus is, therefore, very similar to that of Paramecium in spite of the behavioral differences during preconjugant interaction—for example, presence (E. crassus) versus absence (Paramecium) of the waiting period. This investigation also supports the positive feedback hypothesis of the mating reaction by Heckmann and Siegel ('64). Our finding of the new reaction at the beginning of the interaction might provide a new clue for the analysis of preconjugant interaction in ciliates.
Enzymatic correlates and ontogeny of uricotelism in tree frogs of the genus Phyllomedusa
Authors: Shoemaker Vaughan H. , McClanahan Lon L. 
Published: June 2005

AbstractActivities of arginase, xanthine dehydrogenase, and uricase were measured in liver and kidney of adult Phyllomedusa sauvagei and P. hypochondrialis to examine the enzymatic basis of their unusual ability to excrete uric acid. Comparable values were obtained for two species of ureotelic anurans and a uricotelic lizard. Both Phyllomedusa species exhibited high hepatic and renal levels of xanthine dehydrogenase, whereas this enzyme was not detected in the livers of the ureotelic frogs or the lizard. Hepatic xanthine dehydrogenase was significantly higher in P. sauvagei, which excretes urate predominantly, than in P. hypochondrialis, which excretes 20% of its nitrogen as urate. Hepatic arginase was much lower in both Phyllomedusa species than in the ureotelic frogs, but higher than in the lizard. Reduced levels of uricase were also associated with uricotelism in this genus.Xanthine dehydrogenase was present in livers of larval P. sauvagei well in advance of the onset of uric acid excretion late in metamorphosis. Premetamorphic larvae excreted over 50% of their nitrogen waste as urea and the balance as ammonia.
Morphological analysis of the development of the primary organizer in avian embryos
Authors: Triplett Ronald L. , Meier Stephen 
Published: June 2005

AbstractScanning electron microscopic (SEM) analysis of the primary organizer region of the mesoblast of avian embryos, stages 3–5, showed that mesodermal cells gastrulated through the primitive streak are organized into distinct domains as early as stage 3. These domains initiate a metameric pattern consisting of prechordal plate and the first pair of somitomeres. The prechordal plate first appears immediately anterior to the primitive streak, along the embryonic midline, whereas the somitomeres are located on either side of the prechordal plate in the paraxial mesoblast region. The appearance of a metameric pattern during mesoblast expansion preceeds the formation of Hensen's node and full elongation of the primitive streak. By stage 4 of development the primitive streak is fully elongated, and Hensen's node is established as a raised hillock of epiblast at the cranialmost end of the axis. Also at this stage, avian embryos show the first indication of notochord formation. The notochord initially appears as a highly condensed, elliptical domain of concentrically organized chordamesoblast cells (100μm in length), deposited along the midline between the prechordal plate and Hensen's node (the source of chorda cells). This initial group of notochord cells has been termed a notochord segment. Continued regression of Hensen's node along the primitive streak results in the sequential generation of paraxial somitomeres and axial notochord segments, each segment measuring approximately 100 μm in length. By stage 5, the avian embryonic axis contains four pairs of somitomeres and four axial notochordal segments.
Intercalary and supernumerary regeneration in limbs of stages of the Egyptian toad, Bufo regularis Reuss
Authors: Michael Milad I. , Hassona Abdulla A. 
Published: June 2005

AbstractIntercalary regeneration in the hind limbs of four larval stages of Bufo regularis Reuss (numbers 53, 54, 55, 56) was studied by either removal of the thigh region or removal of the shank and base of ankle region. No intercalary thigh regeneration had taken place in any of these stages. However, intercalary regeneration of the shank/ankle region took place in 52% of the cases of stage 53, in 40% of the cases of stage 54, in 22% of the cases of stage 55, but in none of the cases of stage 56. The intercalated skeleton, particularly that of the ankle, showed deformity in its organization by stage 55. Histologically, in a time series of cases fixed between the first and fifteenth postoperative days, mesenchyme cells began to accumulate and to intervene between the stump and graft tissues around the sixth day, in positive cases. The origin of these cells from stump or/and graft tissues could not be ascertained. Supernumeraries appeared close to the transplantation sites, of both levels, in the operated cases of three stages but not in the case of stage 56. Their incidence faded proximodistally, being lower at the thigh level than at the shank/ankle level. When two or more supernumeraries appeared in one case, they were oriented, according to their toes' arrangement, as mirror images to each other and relative to the graft itself, following Bateson's rule. We conclude that intercalary and supernumerary regeneration may be parallel to the normal regeneration events, since all are governed by the level of transplantation or transection and the grade of differentiation of the limb tissues at that level.
Macrocyst formation in Dictyostelium discoideum: Mating or selfing?
Authors: Bozzone Donna M. , Bonner John T. 
Published: June 2005

AbstractIt is known from previous work that macrocysts are formed when the two strains of Dictyostelium discoideum (NC4 and V12) are mixed. By culturing NC4 and V12 amoebae together in various ratios and at several densities, and in experiments using vitally stained cells, we have shown that the number of macrocysts formed is directly related to the number of V 12 (but not NC4) cells present and that macrocysts may occur without sexual fusion.
Relationships between size of hypostome and number of tentacles in hydra
Authors: O'hern Jennie , Lenhoff Howard M. 
Published: June 2005

AbstractPlots of the circumference of the hypostome of hydra against the number of tentacles surrounding each hypostome gave a linear relationship. The slope of the line is a characteristic of each species and strain of hydra studied and represents the amount of the circumference of the hypostome relegated to each tentacle. We interpret the intercept on the ordinate of such plots to represent the minimum amount of tissue needed, expressed as circumference of that hypostome, before a first tentacle can form. Hypostomes of newly dropped buds have about the same circumferences as those of adult animals. Diagrams of spacing patterns of tentacles from different species illustrate that the larger the animal, the greater the space between the tentacles. Intertentacular space occupies from 22 to 37% of the hypostome circumferences. The relationship between the average size of the hypostome for a number of groups of hydra and the average size of an animal (measured in micrograms of protein per animal) shows that the size of the hypostome is proportional to the size of the group of hydra being measured, with larger species of hydra having larger hypostomes until a maximum size is reached. We noticed a similar relationship between the part of the circumference of the hypostome occupied to each tentacle vs. animal size. Apparently more hypostomal tissue is allotted to each tentacle in specimens of larger species than to those of smaller ones, and the amount of hypostomal tissue per tentacle reaches a limit regardless of the size of the species.
Blastocyst protein synthesis during obligate delay of implantation and embryo activation in the western spotted skunk
Authors: Rourke A. W. , Mead Rodney A. 
Published: June 2005

AbstractThe in utero protein synthetic activity of embryos of the western spotted skunk has been examined by one‐dimensional gel electrophoresis and fluorography. The results indicate that delayed‐implanting embryos synthesize a large variety of proteins with molecular weights from < 15,000 to > 200,000. Delayed‐implanting blastocysts synthesize several very large proteinaceous molecules which do not appear to be produced by activated, preimplantation embryos. Activated embryos show increased synthetic activity, but there are many qualitative similarities in the molecular weight profiles characteristic of delay and activated blastocysts.
Ultrastructure of the body‐wall muscle of the ascidian Halocynthia roretzi: Smooth muscle cell with multiple nuclei
Authors: Shinohara Yoshiko , Konishi Kazuhiko 
Published: June 2005

AbstractThe structure of the body‐wall muscle of the ascidian, Halocynthia roretzi, was investigated by electron and light microscopy. Thin (about 8 nm in diameter), (18–20 nm in diameter), and 10‐nm filaments were seen in this muscle cell. These filaments, however, did not have the regular arrangement of a striated or oblique structure. We also found by three‐dimensional reconstruction that this muscle cell is multinucleated. Based on these observations, we report that the body‐wall muscle of the ascidian, Halocynthia roretzi, is smooth and multinucleated.
Influence of vasopressin and oxytocin on neoteny in the adult mexican axolotl Ambystoma mexicanum
Authors: Wells Dan E. , Moser Charles R. 
Published: June 2005

AbstractLysine‐vasopressin and oxytocin were tested on the normally neotenous adult Mexican axolotl, Ambystoma mexicanum, to determine their influence on metamorphosis. The salamanders were divided into four groups, and daily injections of saline, lysine‐vasopressin, oxytocin, and TSH were made over a 28‐day test period. Tail height, gill length, and body weight were measured as indicators of metamorphic change. Additionally, thyroid uptake of 131I was determined.The results showed that the vasopressin and oxytocin groups had a significant (P < 0.01) loss in tail height and body weight compared to controls, but showed no gill rachis resorption or 131I uptake. These results suggest that the effects of vasopressin and oxytocin were not mediated by TSH and thyroxine, but rather may be caused by an antagonism of prolactin.
Bioelectric activity in the rabbit ear regeneration
Authors: Chang K. S. , Snellen J. W. 
Published: June 2005

AbstractA 1‐cm‐diameter hole was punched through rabbits' ears. The surface potentials during wound healing of regenerating (normal) and partially and nonregenerating (decartilaged) ears were measured. The time sequence of these surface potentials were similar to those reported to occur in regenerating amphibians forelimbs. A small positive potential was observed for about 1 week, and this was followed by a larger negative potential of up to 20 mV, with different durations. The duration of the positive potential was about the same as which was observed in amphibians. The duration and the amplitude of the negative potential were greatest for completely regenerating ears with overgrowth, smaller for partially regenerating ears, and smallest for the nonregenerating ears. The surface potential was localized. If a nipple‐shaped outgrowth developed after the hole was closed, the surface potential was observed only on this outgrowth; immediately outside it, the potential was normal. We concluded that the negative bioelectric activity accompanies growth, and while growth continues, negative bioelectric potential continues.
Differential proliferation in morphogenesis of lateral body folds
Authors: Miller S. A. 
Published: June 2005

AbstractMorphometric analysis and thymidine autoradiography were used to test the hypothesis that differential growth in the form of proliferative asymmetry is a major contributor to formation of lateral body folds in somatopleure. Chick embryos provided an opportunity to study both spatial and temporal differentials within an individual stage of development. Ectoderm and mesoderm were studied as separated tissues. Thymidine labeling index ranged from 34% to 49% in ectoderm and 43% to 66% in mesoderm and was assumed to reflect rate of proliferation in populations with a 100% proliferation index. Density of cell ranged from ten to 13 cells/1,000 μm2 in ectoderm and ten to 15 cells/1,000 μm2 in mesoderm, with a mean density of 12 cells/1,000 μm2. Cellular proliferation was important in folding, because ectoderm showed highest frequencies of labeling and highest cell density in folding levels. Correlation of proliferative differentials with morphogenesis suggests that proliferation is the form of growth contributing to formation of lateral body folds in 20‐somite chick embryos.
The distribution and partial characterization of carbonic anhydrase in selected aquatic and terrestrial decapod crustaceans
Authors: Henry Raymond P. , Cameron James N. 
Published: June 2005

AbstractA sensitive pH‐stat assay was used to determine the distribution in aquatic and terrestrial decapod crustaceans, correlation to osmoregulation, and selected kinetic properties of carbonic anhydrase. In all species the enzyme was concentrated in the gills, and specifically the posterior three or four gill pairs. Activity was highest in the gills of osmoregulating species, and the enzyme could be localized in the areas of the gill lamellae which contained a high density of salt absorbing cells. The enzyme from the blue crab, Callinectes sapidus, exhibits a number of characteristics remarkably similar to the Na+/K+ ATPase from that species. Both enzymes show the same inter‐ and intrabrachial distribution and the same reactions to altered environmental salinity. Branchial CA from both species was inhibited by high concentrations of NaCl and increasing pH. The enzyme showed a temperature optimum of 25°C. On the basis of these initial results, it appears that crustacean gill carbonic anhydrase plays an important role in the blood osmoregulatory process.
Cytokinesis: The effect of initial distance between mitotic apparatus and surface on the rate of subsequent cleavage furrow progress
Authors: Rappaport R. 
Published: June 2005

AbstractThe purpose of this investigation was to determine whether furrows which develop in surfaces distant from the mitotic apparatus function at the same rate as those which develop in surfaces close to the mitotic apparatus. Fertilized, denuded Echinarachnius parma eggs were flattened to a diameter of 175 μm and a thickness of 60 μm 30 to 45 minutes before cleavage in such a way that the mitotic apparatus was eccentric. The initial distance between the mitotic apparatus and the equatorial margin before furrowing was determined as well as the rates of progress of the furrows formed in the opposite margins. The mean rate of progress of furrows which develop in margins 100 to 110 μm from the mitotic apparatus was 5.2 ± 2.8 μm/minute (n = 11). Furrows that developed in margins 65 – 75 μm from the mitotic apparatus progressed at a rate of 10.8 ± 1.8 μm/minute (n = 12). The difference between the means is significant (P < 0.001; t = 6.04; 21 degrees of freedom). The ten fastest furrows progressed at a mean rate of 12.1 ± 0.2 μm/minute and the mean initial distance was 76.3 ± 6.7 μm. The ten slowest furrows progressed at a mean rate of 2.9 ± 0.9 μm/minute and the mean initial distance was 100.5 ± 8.7 μm. The difference between the means of the initial distance measurements is significant (P < 0.001; t = 6.97; 18 degrees of freedom). There was a positive correlation between the difference in initial distances and the difference in rates of progress of two furrows formed in the same cell (r = 0.68; P < 0.005; n = 37) as well as an inverse proportionality between the ratio of the rates of the slower and faster furrows and the ratio of the distances from the mitotic apparatus to the closer and more distant margins (r = 0.63; P < 0.005; n = 37).