bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrophoretic characterization of soluble proteins from dental tissues (polyphyodonts and diphyodonts species)
Authors: Lemus David , Illanes Julio , Fuenzalida Marcela , Repetto Yolanda , De La Vega Yolanda Paz , Blańquez Maria José
Published: June 2005

The developmental processes related to odontogenesis are similar in all vertebrates and they occur during embryogenesis. The dental papilla can exercises directive morphogenetic role on epithelia of different phylogenetic origin. In our laboratory we have previously shown that cultured heterologous tissue recombinations between adult lizards dental papillae and quail epithelia were capable of producing odontogenesis and amelogenesis. Employing sodium dodecyl‐sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) according to Laemmli ('70, Nature, 227:680–685.) and two‐dimensional polyacrylamide gel electrophoresis (2‐D PAGE) (O'Farrell, '75, J. Biol. Chem., 250:4007–4021.), we have examined the distribution of soluble proteins with respect to isoelectric point and molecular weight of dental papillae isolated from tooth germs at bell stage of adult lizard Liolaemus tenuis tenuis (polyphyodont species) and dog fetuses Canis familiaris (diphyodont species). A comparison was also made with dental pulps from adult dogs. Some dental papillae from lizard tooth at bell stage were recombined with quail ectoderm and cultured in explant for 8 days. Furthermore, the histological analysis of dental papillae from lizard and dog fetus showed that dental papillae from both species contain preodontoblast cells, scarce extracellular matrix, and some blood vessels. Dental pulp from adult dogs is composed of odontoblast and fibroblast cells, extracellular matrix, collagen, blood vessels, etc. The control heterologous recombinants after the culture period differentiated chimeric tooth structures, showing that the dental papillae were capable of producing developmental instructions. The electrophoretic study of the supernatants showed differences and similarities. Under SDS‐PAGE the presence of one band of an approximate molecular weight of 49.000 daltons was disclosed, which seems to be unique to dental papilla from adult lizards and dog fetuses. Under 2‐D PAGE protein patterns from adult lizard and dog fetuses disclosed also two protein spots with an approximate molecular weight of 49.000 daltons and isoelectric point of pH ranges between 6 and 7.5. Apparently these spots are unique to both patterns and would have some significance in odontogenesis.
Ferritin in mantle pore cells and its role in reproduction of Helisoma duryi (mollusca: Pulmonata)
Authors: Miksys S. L. , Saleuddin A. S. M.
Published: June 2005

This study was undertaken to investigate the ferritin content of pore cells in the mantle of Helisoma duryi and the possibility of these cells being a source of vitellogenic ferritin. Ultrastructurally pore cells in the mantle resemble those previously studied in the heart/kidney region, except that their plasma membrane is less elaborate. The presence of iron is demonstrated in the cells by the Prussian blue reaction, and in the ferritinlike contents of cytoplasmic vesicles by energy dispersive X‐ray analysis. Egg‐laying activity begins 2 days after virgin snails are allowed to mate. By means of radioimmunoassay it is found that mantle (containing pore cells) ferritin content increases rapidly at the onset of egg‐laying, then declines to reproductive levels. As it declines, the blood ferritin content increases to reproductive levels. Ovotestis and digestive gland ferritin contents drop at the onset of egg‐laying, then rapidly return to reproductive levels. The relationships between the ferritin contents of these four tissues at the onset of and subsequent to egg‐laying are discussed. The ferritin contents of various tissues are determined by radioimmunoassay (RIA) after the removal of endocrine dorsal bodies from reproducing snails. The ferritin levels remain unchanged in the blood and digestive gland, increase in the mantle, and decrease in the ovotestis. A possible influence of dorsal body hormone on ferritin uptake by vitellogenic oocytes is discussed.
Ca2+ ionophore and phorbol ester stimulate taurine efflux from skate erythrocytes
Authors: Leite Margarette V. , Goldstein Leon
Published: June 2005

Hypotonic (approximately 1/3) medium stimulated efflux of taurine from skate (Raja erinacea) RBC approximately twofold at 30 and 60 min incubation. Both Ca2+ ionophore (A23187, 10−7 M) and phorbol ester (phorbol 12‐myristate 13‐acetate, 10−7 M) mimicked the effects of hypotonicity on taurine efflux. Calmodulin was probably not involved in the responses to hypotonicity and Ca2+ ionophore, since calmodulin inhibitors did not block either basal taurine release or hypotonic‐induced stimulation of taurine release. These results suggest that cell Ca2+ and protein kinase C may both play a role in modulating taurine efflux.
A comparison of aromatase, 5α‐, and 5β‐ reductase activities in the brain and pituitary of male and female quail (C. c. japonica)
Authors: Schlinger Barney A. , Callard Gloria V.
Published: June 2005

In numerous vertebrate species including Japanese quail (Co‐turnix coturnix japonica), actions of testosterone (T) on neuroendocrine target tissues are mediated in part by conversion to estrogenic and androgenic metabolites. In order to assess which pathways were favored in each identified androgen target area in quail brain and whether there were discernible sex differences, we developed an assay for simultaneously quantifying aromatase, 5α‐, and 5β‐reductase. In addition, we made the first definitive identification of aromatase in quail pituitary and compared all three enzyme activities in the pituitary of males and females. Enzymes were measured in tissue homogenates by the conversion of [3H]androstenedione to [3H]estrone, [3H]5α‐androstanedione, and 5β‐androstanedione. Aromatase activity was restricted to limbic tissues (anterior hypothalamus > posterior hypothalamus > septum > archistriatum containing nucleus taenia) while hyperstriatum, cerebellum, and midbrain containing nucleus intercollicularis were aromatase‐negative. Quail pituitary aromatized androgen at rates equivalent to anterior hypothalamus pre‐optic area (aHPOA). 5α‐ and 5β‐reductase were present in all tissues tested. Aromatase was significantly higher in aHPOA and pituitary of males, whereas 5α‐reductase was significantly higher in female pituitary. These data suggest that a complex of androgen‐metabolizing enzymes controls the neuroanatomic (spatial) distribution of active hormone in neuroendocrine tissues and that quantitative differences between males and females may account for sex differences in behavior.
Penetration of mouse eggs at various intervals after insemination as influenced by concentration of sperm and strain of male
Authors: Robl J. M. , Dziuk P. J.
Published: June 2005

This study was conducted to determine the extent to which the percentage of mouse eggs that were penetrated by sperm at the end of the period of sperm penetration was due to the proportion of eggs penetrated per unit of time and to the span of time of sperm penetration. Female mice of ICR strain were inseminated 1.5 hr after ovulation with 5 × 106 sperm/50 μl from males of DBA/2N, CF1 or C57BL/6N strains to determine the effect of the male. To determine the effect of concentration of sperm ICR females were inseminated with 2, 4, 6, or 8 × 106 sperm/50 μl from CF1 males. Females were killed at various intervals after insemination and the eggs were recovered and examined for evidence of penetration by a sperm. The time intervals from both insemination to the onset of egg penetration and from insemination to cessation of penetration were similar for the three strains of males. Throughout the period of penetration of eggs a constant percentage of eggs was penetrated per hour for a particular strain of male. The relative percentage penetrated per hour very closely approximated the relative percentage of eggs finally penetrated for each strain of male. The percentage of eggs penetrated per hour was linearly positively related to the concentration of sperm inseminated. The final percentage of eggs penetrated depended primarily on the rate at which the eggs were penetrated during the period of sperm penetration and not on the length of the period of egg penetration which was constant.
Short‐term changes in levels of cyclic AMP, adenylate cyclase, and phosphodiesterase during the initiation of sperm motility in rainbow trout
Authors: Morisawa Masaaki , Ishida Katsumi
Published: June 2005

In order to clarify the role of the system that generates and degrades cyclic AMP during the initiation of motility of trout sperm, short term changes in levels of intraspermatozoal cyclic AMP, adenylate cyclase, and phosphodiesterase were measured. Levels of cyclic AMP and the activity of adenylate cyclase increased and reached a maximum level 1 sec after transfer of sperm to K+ ‐free medium, where they became motile, and then decreased rapidly. However, there were no changes in either parameter in sperm which remained immotile in K+ ‐rich medium. In addition, an increase in the activity of phosphodiesterase was observed 4 sec later than the increase in levels of cyclic AMP and adenylate cyclase. These findings suggest that a very rapid change in the level of intracellular cyclic AMP occurs within 1 sec, at the moment of spawning, by the activation of adenylate cyclase and phosphodiesterase, and regulates the initiation of trout sperm motility.
Differentiation of the accessory cells and structural regionalization of the oocyte in the ascidian Ciona savignyi during early oogenesis
Authors: Sugino Yasuo M. , Tominaga Akio , Takashima Yoichiro
Published: June 2005

The process of oogenesis in Ciona savignyi was studied at the ultrastructural level to understand the development of the accessory cells and the relationship of the oocyte and its accessory cells to the germinal epithelium. There are two kinds of small cells, dark cells and clear cells, adjacent to the oocyte in the germinal epithelium. The previtellogenic ovarian follicles can be classified into four stages on the basis of accessory cell differentiation and chorion formation. At stage 1, the oocyte is enclosed by the primary follicular cells and the outer follicular cells, which resemble the dark cells and the clear cells, respectively. Late in this stage, the chorion rudiment and microvilli‐like projections appear first at the area of the oocyte adjacent to the germinal epithelium. The chorion rudiment is distributed as patches on the oocyte surface and divides the primary follicular cells into inner and outer groups at stage 2. The rudiment covers the oocyte entirely, and the inner group of the primary follicular cells differentiates into the test cells, whereas the outer group becomes the inner follicular cells at stage 3. These cells contain much rough endoplasmic reticulum and electron‐dense granules. At stages 2 and 3, subsurface cisterns are frequently observed at the oocyte surface facing the primary follicular cells or the test cells. The dense granules of the test cells become larger, whereas those of the inner follicular cells appear to become vacuolated at stage 4.
Separation and functions of two acyl CoA transferases from Ascaris lumbricoides Mitochondria
Authors: Saz Howard J. , deBruyn Becky S.
Published: June 2005

Many invertebrates accumulate propionate, or products derived from propionate, as products of fermentation. Evidence has been reported that the nematode, Ascaris suum, the cestode, Spirometra mansonoides, and the trematode, Fasciola hepatica, accumulate propionate by means of an adenosine triphosphate (ATP)‐generating decarboxylation of succinate. To generate energy, an acyl coenzyme A (CoA) transferase that would transfer CoA to succinate is required as one component of the sequence of reactions.

Recently, an acyl CoA transferase was isolated from Ascaris mitochondria and purified to electrophoretic homogeneity. However, upon examination of the substrate specificities of this enzyme, it was found essentially to lack the ability to use succinate or succinyl CoA as an acceptor or donor of CoA, respectively. Therefore, this transferase could not serve to activate succinate.

This article describes the isolation of an additional acyl CoA transferase from Ascaris mitochondria that appears to be unique in its substrate specificity and that could easily account not only for the activation of succinate but also for the regulation of succinate metabolism primarily in the direction of decarboxylation to propionate. This is in contrast with mammalian tissues, which act in the opposite direction by catalyzing the fixation of CO2 into propionate, thereby forming succinate and accounting for the glycogenic nature of dietary propionate. Possible functions of the two acyl CoA transferases are discussed.
Radioimmunoassay and characterization of renin‐angiotensin system in the fresh‐water turtle
Authors: Cho Kyung Woo , Kim Suhn Hee , Koh Gou Young
Published: June 2005

We developed a radioimmunoassay (RIA) for plasma renin concentration (PRC) and characterized the renin‐angiotensin system (RAS) in the fresh‐water turtle (Amyda japonica).

Among three antisera to human angiotensin I (ANG I) had different specificities to ANG I analogues; the antiserum with the highest specificity was used to measure the PRC. The amount of ANG I generated from incubation of turtle renal extracts with turtle plasma was linear with respect to volume of renal extract and incubation time. Turtle renin cleaved heterologous substrates from nephrectomized rats and rabbits but had a higher affinity for renin substrate from rabbits. The generation of ANG I with heterologous substrate was temperature dependent (optimum‐37°C) and the pH optimum was at 5.0–5.5. Furosemide (5 mg/kg) did not affect PRC. Hemorrhage (1% and 3% of body weight) decreased blood pressure. The PRC did not change with the lower hemorrhage, but increased significantly with massive hemorrhage. Angiotensin II increased blood pressure with no effect in PRC. The PRC of fresh‐water turtles transferred to 4°C increased significantly.

The RAS in the fresh‐water turtle seems to be involved in the adaptation of environmental temperature rather than in the acute control of blood pressure although the mechanism is not known.
Purification and identification of vitellogenin and its immunohistochemical detection in growing oocytes of the teleost, Oryzias latipes
Authors: Hamazaki Tatsuo S. , Iuchi Ichiro , Yamagami Kenjiro
Published: June 2005

“Probable vitellogenin” [Hamazaki et al. (1985) J. Exp. Zool., 235:269–279] of the medaka, Oryzias latipes, was purified from the ascites of estrogen‐fed (EF) fish and was identified as the real vitellogenin by examining some of its biochemical characteristics. It has an amino acid composition and phosphorus content (0.8%) quite similar to those of the vitellogenin of rainbow trout and goldfish. The molecular weight (mw) in the native state was about 420,000, but sodium dodecyl sulfate denaturation produced a group of peptides that included a major peptide of about 200,000 mw with an isoelectric point of 3.8–4.0. Immunohistochemical observations with the use of the anti‐vitello‐genin antibody raised against the purified vitellogenin as a probe indicated that a considerable immunoreactivity appeared in some vesicles of the oocytes at the yolk‐vesicle stage (ca, 150–250 μm in diameter). However, yolk deposition in the oocytes seemed to occur at the later stage (vitellogenic stage, over 300 μm in diameter) as judged from histological examination of the the hematoxylin‐stained materials. Moreover, the immunofluorescence was observed in the intercellular spaces among the follicle cells of the vitellogenic oocyte. The observation indicates that the pathway of vitellogenin transportation through the follicle cell layer into the oocyte is present in the extracellular matrix of the follicular epithelium.
Follicle cell regulation of mammalian oocyte growth
Authors: Buccione Roberto , Cecconi Sandra , Tatone Carla , Mangia Franco , Colonna Rosella
Published: June 2005

To investigate mechanisms of follicle cell control on mammalian oocyte growth, preantral mouse oocytes free from surrounding follicle cells were individually cocultured with monolayers of different somatic cells competent to form gap junctions, and the rate of in vitro oocyte growth was directly correlated with the level of metabolic coupling on the same cells. The results indicate that 1) at a similar extent of metabolic coupling, mouse oocytes grew on follicle cells but not on 3T3 and Sertoli cell monolayers, and 2) the growth rate of oocytes cultured on follicle cells was dependent on the extent of metabolic coupling. It was concluded that gap‐junction‐mediated mutrition of ovarian mouse oocytes exerted by somatic cells is necessary but not sufficient to maitain oocyte growth. A specific regulatory role of follicle cells on mammalian oocyte growth is proposed.
Amino acid transport in bivalve mollusc mitochondria: The role of the proton motive force and monovalent cations in proline oxidation by oyster (Crassostrea virginica) gill mitochondria
Authors: Moyes Christopher D. , Ballantyne James S.
Published: June 2005

The role of the proton motive force (PMF) and significance of the common intracellular monovalent cations (Na+ and K+) in proline oxidation by oyster (Crassostrea virginica) gill mitochondria were examined. Proline was oxidized at moderate rates in the presence of ADP under isosmotic conditions. Oxidation of proline was inhibited by CCCP (carbonyl cyanide m‐chlorophenylhydrazone), an uncoupler of oxidative phosphorylation. Oxidation of pyruvate, but not succinate (each oxidized at moderate rates), was inhibited by CCCP, confirming that the PMF was at least partially dissipated. These data suggest that transport of proline is dependent on some component of the PMF, either the pH gradient or the membrane potential. Less inhibition of proline oxidation by CCCP was achieved at higher proline concentrations suggesting that diffusional penetration may become more important as proline concentrations increase. Oxidation of proline was not substantially affected by reducing concentrations of Na+ or K+ or both Na+ and K+ (Na+ < 9 mM; K+ < 1 mM), suggesting that proline transport does not require an inward chemical gradient of these monovalent cations. Monovalent cations stimulated proline oxidation in the order of the Hofmeister series (Na+ > K+ > choline+). The high rate of oxidation achieved using Na+ is unusual and is probably an adaptation related to the high intracellular Na+ concentrations found in many bivalve molluscs.
Dietary regulation of digestive enzyme levels in the water snake, Natrix tessellata
Authors: Zhalka Mhmoud , Bdolah Avner
Published: June 2005

Levels of digestive enzymes were analyzed in water snakes following artificial feeding. A prominent increase of total proteolytic activity in the stomach was evident after feeding with a casein solution or after the snake was offered a fish (9‐ and 6‐fold that of the fasting level, respectively). The activity following feeding with starch was much lower. Increased levels of chymotrypsin(ogen) as well as of amylase were evident in the pancreas 1 day after feeding the snake with fish. A specific induction of increased level of chymotrypsin in the pancreas of adult snakes was achieved by feeding with casein (12‐fold that of the fasting level). In the group fed with starch, the chymotrypsin level dropped, while a 3‐fold increase of amylase was evident. In newborn snakes, fed for the first time, casein induced a dramatic increase in the level of chymotrypsin in the pancreas (58 times the fasting level); feeding with starch induced an approximate 2‐fold increase of chymotrypsin. Histological examination of the pancreas 1 day following casein feeding showed acinar cells loaded with zymogen granules. In starved animals and in snakes fed with starch, a much lower concentration of zymogen granules was observed. The pancreas of the snake may, thus, be most suitable for studying the specific induction of synthesis of digestive enzymes.
Ketoglutarate dehydrogenase from ribbed mussel gill mitochondria: Modulation by adenine nucleotides and calcium ions
Authors: Karam George A. , Paynter Kennedy T. , Bishop Stephen H.
Published: June 2005

The transient accumulation of proline in the gills of the osmotically stressed ribbed mussel (Modiolus demissus), may be controlled by a transient regulation of the α‐ketoglutarate dehydrogenase (KGDH) activity. In this study, KGDH was partially purified from lysed mitochondria of gill tissue by differential centrifugation techniques. Various modulators of enzyme activity assayed at a saturating concentration (2.5 mM) of ketoglutarate (KG), showed inhibition by high concentrations of Cl− (10–100 mM) and a slight activation or inhibition by the other compounds (10 mM), when assayed in the absence of added Ca++. Addition of Ca++ at pH 7.2 caused no change in Ks0.5 for KG and a 1.5‐fold increase in Vmax whereas at pH 7.8, no change in Vmax but a 40–50% decrease in Ks0.5 and slight positive cooperative effects (“napp” 1.4–1.7) were observed. At pH 7.8, addition of adenine nucleotides (AMP, ADP, ATP at 5mM) had no effect on the Vmax; however, ATP and ADP lowered the Ks0.5 by 3.5–4‐fold. The CoA derivatives of short chain fatty acids were found to inhibit the enzyme by 30–60%. This inhibition was reversed by Ca++ but only at higher KG concentrations (250 μM). The enzyme showed a major change in activity at nicotinamide adenine dinucleotide/reduced nicotinamide adenine dinucleotide ratio (NAD/NADH) > 1, an effect that could not be modified by Ca++. It appears, therefore, that the mussel gill KGDH is mainly regulated by changes in mitochondrial pH and ketoglutarate or adenine nucleotide levels, rather than by changes in mitochondrial calcium levels.
Isolation and characterization of a taurine‐specific opine dehydrogenase from the pedicles of the brachiopod, Glottidea pyramidata
Authors: Doumen C. , Ellington W. R.
Published: June 2005

Tauropine dehydrogenase (pyruvate + taurine + NADH ⇋ tauropine + NAD+) was partially purified from the pedicles of the inarticulate brachiopod, Glottidea pyramidata. The molecular mass of this enzyme, as determined by high performance liquid chromatography (HPLC) using a TSK‐ 3000 SW column, was 39,500 daltons. This molecular mass value is consistent with a monomeric structure characteristic of all opine dehydrogenases. Kinetic studies revealed that taurine and pyruvate were the preferred substrates, although other amino acids and keto acids were used to some extent. This enzyme readily oxidized tauropine displaying an apparent Km of 3.1 mM. Taurine was found to be the most abundant free amino acid in neutralized perchloric acid extracts of pedicles. Thus, it is likely that taurine is a physiological substrate. This enzyme shows striking similarities to tauropine dehydrogenases from archeogastropods.
Differentiation of the anterior latissimus dorsi muscle of the chicken examined by anti‐myosin monoclonal antibodies
Authors: Zhang Yatian , Shafiq Saiyid A.
Published: June 2005

Two new monoclonal antibodies (McAbs), ALD‐180 and ALD‐88, produced against the myosin of the slow anterior latissimus dorsi (ALD) muscle of the chicken are described. Their specificity for myosin heavy chain (MHC) was established by radioimmunoassay, immunoautoradiography, and immunofluorescence. They were used in conjunction with McAbs MF‐14 and MF‐30 (which have been characterized previously to be directed against MHC of the fast skeletal muscle) to examine the developmental changes of the chicken ALD muscle. At the 16‐day embryonic, early posthatch, and adult stages the ALD muscle fibers differed in their reaction pattern with the McAbs: at the embryonic stage all fibers reacted strongly with ALD‐180 and weakly with ALD‐88 and MF‐30; at the early posthatch stage there was a checkerboard pattern with many fibers not reacting with any of these three McAbs; and at the adult stage all fibers reacted strongly with ALD‐180 and ALD‐88 and weakly with MF‐30. The MF‐14 antibody did not react with ALD muscle at any developmental stage. The mature pattern of immunoreactivity of the ALD muscle fibers with the antibodies was established only after 9 weeks posthatch, and during this 9‐week period the immunofluorescence changes were nonsynchronous. Based on immunocytochemical evidence of changes in myosin isoform expression, this study clearly demonstrates a distinctive neonatal (early posthatch) stage in the development of the chicken slow muscle.
Uterine luminal proteins during the preimplantation period in the ferret
Authors: Foresman Kerry R.
Published: June 2005

The pattern of synthesis of uterine luminal proteins during the 6‐day preimplantation period of the ferret has been analyzed by polyacrylamide gel electrophoresis and fluorography. The results demonstrate that several classes of protein, in particular those of molecular weights of 75,000, 58,000, 50,000, 18,000, and 8,000, are actively synthesized and appear in the uterine lumen during this period. Quantitative changes in the amount of radioactivity incorporated by specific proteins as viewed on autoradiograms are also suggested in association with the observed qualitative changes and both become more prevalent as implantation approaches.
Role of fat bodies in oocyte growth and recruitment in the frog Rana cyanophlyctis (Schn.)
Authors: Prasadmurthy Y. S. , Saidapur S. K.
Published: June 2005

Effects of 30‐day bilateral fat body excision in February and November and replacement with 10 or 20 mg fresh aqueous fat body homogenate 6 days a week for 30 days, unilaterally or bilaterally fat body excision plus 20 IU human chorionic gonadotrophin (HCG) in February, and long‐term (60 days) fat body excision in March—April were studied in Rana cyanophlyctis. In addition, the effect of ovariectomy on fat body weights in February and November was also studied. The frogs were fed 6 days a week with live guppies and libitum. The ovarian follicular kinetics was studied by estimating the numbers of first growth phase (FGP), medium and large second growth phase (MSGP and LSGP) oocytes and atretic follicles. Regardless of season, 1‐month fat body ablation caused a significant reduction in LSGP oocytes, gonadosomatic index, and increase in atretic follicles. Administration of 20 mg fat body homogenate to fat‐body‐excised frogs prevented the fall in the number of LSGP oocytes and the gonadosomatic index. In fact, there was a significant increase in the LSGP oocytes and percentage weight of ovaries in these frogs. Follicular atresia was greatly reduced due to fat body homogenate (10 or 20 mg) administration. In 30‐day unilaterally fat‐body‐extirpated frogs, the mean weight of the ipsilateral ovary was reduced to 50% compared to that of the shamoperated frogs due to increased follicular atresia and associated decrease in LSGP oocytes. The administration of HCG increased recruitment of SGP oocytes in unilaterally as well as bilaterally fat‐body‐ablated frogs. This was accompanied by a reduction in atresia of oocytes and elevation of the gonadosomatic index. Interestingly, in long‐term fat‐body‐ablated frogs, ovarian weight recovered and follicular kinetics in them was identical to that found in shamoperated control frogs. Furthermore in 30‐day ovariectomized frogs, in both seasons there was a significant rise in fat body weights. The above findings in R. cyanophlyctis suggest that fat bodies have a role in vitellogenesis, and they serve as immediate sources of lipid energy needed for follicular growth. If adequate food is provided to fat‐body‐excised frogs, after an initial setback, ovarian growth commences by drawing lipids from other sources. It is concluded that fat bodies in the frog have a supporting and possibly not an obligatory role in vitellogenic growth of oocytes.
Fucosylated glycoconjugates appear on mouse embryos during blastocyst formation
Authors: Dealtry Gillian B. , Curry Mark R. , Sellens Martin H.
Published: June 2005

Mouse embryos were analysed for expression of surface glycoconjugates using a panel of fluorescein‐labelled lectins. Morulae and blastocysts but not early cleavage stages stained brightly with fucose binding lectins. By contrast, cleavage stages stained brightly with all the other lectins tested. These findings provide evidence for substantial reorganisation of the cell surface during blastocyst formation and are consistent with a role for fucosylated glycoconjugates in compaction.
Abnormal Development in Artemia: Defective emergence of the prenauplius with bicarbonate deficiency
Authors: Trotman Clive N. A. , Gieseg Steven P. , Pirie Richard S. , Tate Warren P.
Published: June 2005

Prenauplius larvae of the brine shrimp Artemia emerged abnormally from their survival cysts in certain substitutes for seawater unless the concentration of metabolising cysts exceeded about 1 mg/ml. Emergence was normal in natural seawater. The abnormality was manifest as the release of prenauplii trapped within an additional membrane surrounding the hatching membrane, preventing normal development. It was shown to be caused by a failure of the cyst inner cuticular membrane to rupture when the remainder of the cuticle and the external tertiary envelope ruptured. The biochemical basis of the abnormal emergence was found to be a deficiency of bicarbonate ion, and a requirement for this ion for normal emergence was demonstrated. In the model of the normal emergence mechanism, bicarbonate is now implicated as an additional component in the energy‐requiring process for the generation of the osmotic potential necessary for successful expulsion of the prenauplius.
Actin‐plasma membrane associations in mouse eggs and oocytes
Authors: Longo Frank J.
Published: June 2005

Using rhodamine‐phalloidin stained preparations and extracted specimens labeled with heavy meromyosin or run on polyacrylamide gels, actin–plasma membrane associations in mouse mature eggs at the second metaphase of meiosis and oocytes at meiotic prophase have been examined. Cortices of extracted oocytes possessed numerous actin filaments that emanated from the plasma membrane delimiting regions between microvilli and from microvillar apices. The membrane anchorage sites of actin filaments were marked by an electron dense material on the inner leaflet of the plasma membrane. The free ends of filaments emanating from the plasma membrane of oocytes intermeshed to form a dense, cortical layer. With meiotic maturation, changes in the organization of cortical actin were first noted approximately 3 hr after the chromosomes had become localized at the oocyte's periphery. Fewer and shorter actin filaments, which did not form a well‐defined layer as in oocytes, were connected with electron‐dense material to the inner leaflet of the plasma membrane of extracted egg cortices in regions other than that associated with the meiotic spindle. Cortical actin adjacent to the meiotic spindle, however, was organized into a dense, cresentic aggregation in which clusters of filaments emanated from electron‐dense regions associated with both the inner and outer leaflets of the plasma membrane. These observations indicate that mouse oocyte maturation not only involves changes in the distribution of cortical actin but also local alterations in the association of actin with the plasma membrane.
The absence of DNA from the blood serum of Bufo arenarum
Authors: De Recondo Marta Elena Fernández , De Arcuri Beatriz Eugenia Fernández , Recondo Eduardo Francisco
Published: June 2005

The absence of DNA from the blood serum of the toad Bufo arenarum was confirmed by classical colorimetric techniques and by a new method which allows differentiation between DNA and the glycosaminoglycans (GAG). A component of serum which had some of the properties of DNA was identified as a GAG. This component gave positive reactions in colorimetric assays for DNA, but the absorption spectra were completely different from those of authentic DNA. The compound was also not hydrolized at all by treatment with deoxyribonuclease.
Role of carbohydrates in cell‐substrate interactions during newt epidermal cell migration
Authors: Atnip Karen Davenport , Mahan James T. , Donaldson Donald J.
Published: June 2005

The effect of several solubilized monosaccharides on epidermal cell migration from skin explants of the adult newt was examined. The ability of epidermal cells to migrate on substrates coated with these same sugars or with wheat germ agglutinin (WGA) was also determined. Adding 0.05 M Nacetyl‐glucosamine (GlcNAc) to the medium inhibited epidermal cell migration in dishes coated with either type I collagen or fibrinogen. The same concentration of fucose, galactose, or mannose had no effect. In contrast to type I collagen, which supported considerable migration when dried onto the bottom of plastic dishes, epidermal cells were unable to migrate on dishes coated similarly with WGA, mucin (a protein high in sialic acid residues), or bovine serum albumin (BSA) conjugated to galactose, mannose, or GlcNAc. Red blood cell (RBC) binding assays showed that drying WGA onto plastic did not destroy its GlcNAc binding sites—nor did it damage the GlcNAc residues of BSA‐GlcNAc. The RBC assay also verified that for both these proteins, substrates with distinctly different cell binding capacities had been tested in the migration experiments. In dishes coated with either WGA or BSA‐GlcNAc, red cells bound to dish bottoms in a GlcNAc‐specific manner right up to the margins of explants. Other control experiments showed that the failure of migration in WGA‐ and BSA‐GlcNAc‐coated dishes could not be explained by competition between adsorbed and desorbing protein for cell surface receptors. This work shows that adhesive bonds between epidermal cell surface GlcNAc and a GlcNAC‐specific lectin on the substrate are not by themselves adequate to support cell migration. Nor is GlcNAc, sialic acid, galactose, or mannose alone on the substrate sufficient. In conjunction with our earlier work (Donaldson and Mahan: J. Exp. Zool., 231:211–219, '84; Donaldson, Mahan, Hasty, McCarthy, and Furcht: J. Cell. Biol., 101: 73–78, '85), these observations suggest that factors other than carbohydrate content or capacity to act as a lectin determine whether a given extracellular protein will support migration.
Ontogeny‐related changes in the peptide profiles of the germinal epithelium: Analysis by sodium dodecyl sulfate gradient gel electrophoresis
Authors: Kumari Meena , Duraiswami S.
Published: June 2005

The premise that one manifestation of the nexus between Sertoli cells and germ cells may be an orderly and sequential change in their protein profiles has been examined in relation to the ontogeny of spermatogenesis in the colony‐bred albino rat. Viable “Sertoli cell—germ cell associations”

The term “Sertoli cell—germ cell associations” is used to designate the groups of Sertoli cells together with the associated germ cells (in other words, a part of seminiferous epithelium) that are recovered after enzymatic removal of tunica propri from the seminiferous tubule fragments (Welsh and Wiebe, '75; Meenakumari and Duraiswami, '86b).

isolated from the testes of animals of defined postnatal age and incubated in an appropriate medium were separated into a Sertoli cell and a germ cell fraction and processed for analysis by sodium dodecyl sulfate gradient gel electrophoresis. The resulting stained bands were “mapped” and assigned relative mobility values by comparison with standard marker proteins. This enabled identification by serial number of individual bands from an overall total of 163. For purposes of detailed analysis, they were classified into high, medium‐high, medium, and low molecular weight bands. Two major categories were delineated: 1) those associated uniquely with a specified day of ontogeny and 2) those appearing intermittently. Significantly enough, not one of the bands was encountered on all days examined. The relevance of the patterns observed to the possible exchange of “information” between Sertoli cells and germ cells during spermatogenesis is mooted.
Inhibition of mouse oocyte cyclic AMP phosphodiesterase by steroid hormones: A possible mechanism for steroid hormone inhibition of oocyte maturation
Authors: Kaji Eugene , Bornslaeger Elayne A. , Schultz Richard M.
Published: June 2005

Testosterone, progesterone, and estradiol‐17β each inhibit cAMP phosphodiesterase activity of mouse oocyte extracts in a concentrationdependent manner. This finding provides an explanation for the inhibitory effect of steroid hormones on germinal vesicle breakdown (GVBD) of mouse oocytes in vitro. Furthermore, it raises the possibility that steroid hormones present in follicular fluid participate in maintaining meiotic arrest in vivo by acting in a nonclassical manner.
New evidence of anuran oviducal pars recta involvement on gamete interaction
Authors: Miceli D. C. , Fernández S. N. , Mansilla Z. C. , Cabada M. O.
Published: June 2005

Coelomic oocytes of the toad Bufo arenarum are not fertilizable when inseminated in egg water that assures fertilization of dejellied uterine eggs. However, when coelomic oocytes were pretreated with an extract from oviducal pars recta (PRE) and inseminated in egg water, a high frequency of fertilization was obtained.

In this study the effect of PRE on acrosome breakdown (AB) was studied by means of vitelline envelope (VE) lysis and fertility tests with B. arenarum sperm, and by direct observations with the light microscope of the AB with Leptodactylus chaquensis sperm. The coelomic envelope becomes sensitive to lysin solution only after PRE treatment. The addition of sperm to PR‐treated oocytes, in a medium containing egg water, resulted in a marked swelling and softening of the VE. But this lytic effect by sperm can be observed only when egg water was present in the medium. These results indicate that jelly‐molecules are necessary for the acrosome process to begin and that PR components engulfed in the VE are not capable of inducing AB by themselves. Likewise, incubation of B. arenarum sperm with PRE did not impair their fertilizing capacity and the supernatant of this incubation medium did not have typical VE lytic activity.

Moreover, when the effect of PRE on AB was studied by direct observation of L. chaquensis sperm, it was found that PRE neither induces AB nor modifies its time‐course.
Removal of enveloping follicle cells can trigger resumption of meiotic maturation in Fundulus heteroclitus oocytes
Authors: Greeley Mark S. , Begovac Paul C. , Wallace Robin A.
Published: June 2005

The various somatic cell layers surrounding large (1.3–1.4 mm in diameter) meiosis‐arrested oocytes of the saltmarsh teleost Fundulus heteroclitus were successively removed by a combination of manual dissection and exposure to calcium/magnesium‐free medium. The efficacy of these methods was verified by light and scanning electron microscopy. Oocytes within intact follicles, and oocytes in follicles with the outermost surface epithelium and theca layers removed, typically resumed meiosis only when treated with either a steroid, 17α‐hydroxy‐20β‐dihydroprogesterone, or an aqueous extract of Fundulus pituitaries. In contrast, removal of the follicle cell layer immediately surrounding the oocyte frequently triggered the resumption of meiosis in the absence of exogenous hormonal stimulation. These results suggest that the follicle cells may somehow be responsible for the maintenance of meiotic arrest in non‐hormone‐treated oocytes.
Fucosylated glycoconjugates in mouse preimplantation embryos
Authors: Kimber S. J. , MacQueen H. A. , Bagley P. R.
Published: June 2005

Preimplantation mouse embryos were metabolically labelled with 3H or 14C‐fucose to investigate the synthesis of fucosylated macromolecules. Scintillation counting revealed that there was a progressive increase in both total fucose taken up by the embryo and incorporation of fucose into TCA‐precipitable material as embryos developed from the 4‐cell to the blastocyst stage. This was reflected in the increasing intensity of bands on autoradiographs of radioactive fucose labelled proteins separated on 10% SDS‐PAGs between the 4‐cell embryo (at which stage bands were first detectable) and the blastocyst. Minor qualitative changes in fucoproteins were detected at the time of compaction and additional bands appeared at the blastocyst stage. Preliminary analysis of fucolipids in 6‐ to 8‐cell embryos indicated that an approximately equal amount of fucose was incorporated into lipid and protein. Autoradiographs of semi‐thin sections of 3H‐fucose‐labelled embryos showed substantial amounts of radioactive material in the vicinity of the plasma membrane both adjacent to other cells and facing the zona pellucida. These data would support a predominant role for fucoconjugates in cell surface events in the preimplantation embryo from the 8‐cell stage.
Social control of testicular steroidogenic capacities in the Siamese fighting fish Betta splendens Regan
Authors: Leitz Thomas
Published: June 2005

Male Siamese fighting fish (Betta splendens Regan) of the veiltail variety were raised. At the age of 4 ½ months they were either isolated or community‐housed for 2 ½ months. After that time the relative fin lengths were determined, and the in vitro metabolism of testosterone by the testes of the fishes was investigated. Community‐housed specimens had shorter fins than the isolated males. Their testes formed less 11‐oxy‐ and more 5β‐steroids than those of the isolated males. This difference was even larger when high‐ and low‐ranking community‐based specimens were compared. The appearance of low‐ranking males resembled that of females, and the main products of their testes were 5β‐reduced steroids. These results are interpreted as evidence for a social control of steroid metabolism and hence reproductive ability in the fighting fish.
Effects of colchicine‐ and cytochalasin B‐treatment on the intracellular distribution of yolk droplets, lipid bodies, and golgi apparatus of the chick neuroepithelial cells
Authors: Fernandez J. G. , Chamorro C. A. , de Paz P. , Villar J. M.
Published: June 2005

Treatment with colchicine (antimicrotubular agent) and cytochalasin B (antimicrofil‐amentous agent) has been used to investigate the possible role played by the cytoskeleton in the maintenance of intracellular distribution of yolk droplets, lipid bodies, and Golgi apparatus of the chick neuroepithelial cells. On the one hand, embryos treated with colchicine showed modifications in their distribution patterns of yolk droplets and lipid bodies, which suggests the involvement of the microtubular integrity of neuroepithelial cells in the maintenance of normal distribution patterns. On the other hand, the close relationships between vitelline and lipid inclusions and Golgi apparatus observed in untreated embryos seems to be kept in the embryos treated with colchicine and cytochalasin B. Moreover, from the effects of colchicine on Golgi apparatus position a possible functional role for the microtubular system in the maintenance of Golgi apparatus polarity in the chick neuroepithelial cells can be proposed. The results provided here constitute new information about the cellular mechanisms involved in chick neurulation.
The amylase gene–enzyme system of fishes. I. Developmental expression of amylase in the mosquitofish
Authors: Yardley Darrell G.
Published: June 2005

The objective of this study is to examine the effects of developmental stage on amylase expression in the mosquitofish (Gambusia affinis holbrooki, Poeciliidae). Expression was characterized in terms of amylase activity and amount of amylase protein in five developmental stages: early, mid, and late embryos, 5‐day‐old juveniles, and adults. Two measures of activity were used: a starch‐iodine assay, which measures the change in substrate, and the dinitrosalicyclic acid (DNSA) assay, which measures the change in product. To measure changes in the amount of amylase, the enzyme‐linked immunosorbent assay (ELISA) was used. Highest activity and amount was observed in the adult stage. In general, both increased with development. While the two activity measures were positively correlated, these were only weakly correlated with the amount of amylase. Possible reasons for these weak correlations between amylase activity and amount are discussed.
Response of the interrenal to adrenocorticotropic hormone after short‐term thyroxine treatment of coho salmon (Oncorhynchus kisutch)
Authors: Young Graham , Lin Richard J.
Published: June 2005

The effects of experimentally elevated plasma thyroxine levels on the subsequent response of interrenals of coho salmon (Oncorhynchus kisutch) to adrenocorticotropic hormone (ACTH) in vitro were examined. Animals were treated with thyroxine by immersion (200 μg/L) for 3 days, which resulted in physiological elevations in circulating thyroxine. In animals treated before the parr‐smolt transformation was completed (early smolts), thyroxine had no effect on plasma cortisol levels but significantly enhanced the sensitivity of the interrenal to ACTH in vitro. In animals treated after the period of smoltification (postsmolts), plasma cortisol levels were significantly higher than those of controls; both experimental and control animals had plasma cortisol levels higher than normally observed at this stage of development. The response of the interrenals of thyroxine‐treated postsmolts to ACTH in vitro was significantly lower than that of controls. Results from the experiments using early smolts are in agreement with studies in other vertebrates showing that thyroid hormones are involved in maintaining the normal functioning of corticosteroidogenic tissue and suggest that thyroid hormones may be involved in the activation of the interrenal that occurs during smoltification. The results obtained using postsmolts are more difficult to interpret because of the possibility that these animals were physiologically stressed by the treatment. Increased ACTH release in vivo resulting from stress may have led to a depression of interrenal sensitivity to ACTH in vitro and may have masked a refractoriness of the pituitary‐interrenal axis to thyroxine.
Differential localization of glycoconjugates having affinity for concanavalin A on the surface of the sperm head in the testis, the epididymis, and the ejaculate of the ram
Authors: Delpech S. , Hamamah S. , Pisselet Cl. , Courot M.
Published: June 2005

The localization of Con A receptors on the surface of the head of ram spermatozoa originating from the rete testis, from three regions of the epididymis, or from the ejaculate was investigated using a gold‐Con A labelling technique. Electron microscopic observation revealed three major localizations, each being characteristic of the origin of the spermatozoa: periacrosomal in the rete testis, postacrosomal in the epididymis, on the entire surface of the sperm head in the ejaculate.
Chorionic peroxidase activity in the eggs of the fish Tribolodon hakonensis
Authors: Kudo Shigeharu , Sato Atsuhiko , Inoue Matsuhisa
Published: June 2005

Peroxidase activity was ultracytochemically demonstrated in the vitelline and fertilization envelopes of eggs of the fish Tribolodon hakonensis. The vitelline envelope (VE) was morphologically divided into five layers, from the first to the fifth, numbered in order from the outside of the VE toward the interior, but the micropylar and surrounding region lacked the first layer. Peroxidase activity was localized in the first and second layers, but was much stronger in the latter than in the former. Phosphotungstic acid (PTA) staining was positive in the first layer alone. During the elevation of the fertilization envelope (FE) the peroxidase activity was translocated into the first layer of the FE from the second layer. This translocation resulted in much weaker activity or negativity in the FE second layer. In the micropylar and surrounding region, however, peroxidase activity remained unchanged, and there was no translocation. Transformation of the VE into the FE led to an alteration in the thickness of each layer and in the cytochemical nature of the first layer. There was almost no PTA staining in the FE first layer, except for a few scattered positive spots. A purified and lyophilized VEs‐ or FEs‐NaI‐H2O2 system exerted a cell‐killing effect on three bacterial species tested.