bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of absorbed and nonabsorbed anti‐H‐2 antiserum on mouse blastocysts
Authors: Warner Carol M. , Ostlie Norma S. , Spannaus Donna J. 
Published: June 2005

AbstractConventional antisera and monoclonal antibodies have been used to demonstrate the presence of H‐2 antigens on preimplantation mouse embryos. In this study, the specificity of previously used anti‐H‐2 conventional antisera was tested by absorption of the antisera on spleen lymphocytes. It was found that absorption of the anti‐H‐2 antisera removed all of the antibody reactive with lymphocytes, but only about half of the antibody reactive with embryos. The effect of absorbed and nonabsorbed anti‐H‐2 antisera on mouse blastocysts was tested both by cytotoxicity assays and by electron microscopy. The results suggest that conventional antisera do indeed detect H‐2 antigens on mouse embryos, but they may detect other, as yet undefined, antigens as well.
An ovarian regression syndrome in the platyfish, Xiphophorus maculatus
Authors: Burns John R. , Kallman Klaus D. 
Published: June 2005

AbstractThe highly inbred Coatzacoalcos (Cp) strain of the platyfish, Xiphophorus maculatus, was noted for a high percentage of infertile females (XX). The ovaries of approximately one‐quarter of all females regress. The time of gonadal atrophy varied from before sexual maturation up to 11 months of age. The gonadotropic zone of the pituitary was hypertrophied in regressed females. Transplants of immature testes and ovarian tissue into the caudal musculature of regressed females and the subsequent maturation of the grafts demonstrated that the ovarian degeneration was not due to pituitary or hypothalamic malfunction or an autoimmune disease.The cause of the gonadal degeneration was apparently localized to the ovary itself. This phenomenon was never observed in males (XY). Regressed ovaries fell into two categories, designated types I and II, with all being characterized by the presence of ductlike structures which resembled male efferent ducts, lined by Sertoli cells. Type I ovaries bore a marked similarity to certain mammalian dysgenetic gonads, while type II ovaries contained many proliferating germ cells and could be compared to the human neoplasm termed gonadoblastoma. It is suggested that the physiological lesion responsible for the ovarian regression syndrome involves the processes that control the determination and differentiation of the germ cells similar to those found in human 46,XY gonadal dysgenesis.
Size regulation of regenerated organs in the compound ascidian, Polyandrocarpa misakiensis
Authors: Taneda Yasuho 
Published: June 2005

AbstractFragments of zooids of the compound ascidian, Polyandrocarpa misakiensis, have the capacity for morphallactic regeneration. In untreated fragments of zooids, the sizes of regenerated organs were in proportion to the total sizes of the fragments. If two anterior fragments were fused together at their cut surfaces, double‐zooid monsters were produced, each regenerating the posterior part at the fusion area. Monsters, resulting from the fusion of two anterior fragments of different sizes, regenerated two digestive loops that were similar in size.
Development of sucrase in the chick small intestine
Authors: Matsushita Susumu 
Published: June 2005

AbstractDevelopment of sucrase in the chick small intestine was studied biochemically and immunologically using antiserum prepared against purified chick intestinal sucrase. Sucrase activity was first detectable at 10 days of incubation and increased with age. After a transient drop at 20 days, the activity rapidly increased to the adult level. Immunodiffusion and polyacrylamide gel electrophoretic studies suggested that the sucrase of the embryonic and hatched chick intestines was identical except for a difference in the content of sialic acids. In immunofluorescence and immunoelectron microscopy, sucrase was found to appear on the luminal surface of epithelial cells at 8–10 days of incubation, soon after the start of morphological differentiation from an undifferentiated thick epithelium to a thin simple epithelium.
Autoradiographic studies on the distribution of labeled maternal RNA in early mouse embryos
Authors: Bachvarova Rosemary , Moy Keiko 
Published: June 2005

AbstractMaternal RNA of mouse eggs and embryos was labeled by exposure of growing ovarian oocytes to 3H‐uridine in vivo 8 to 16 days before ovulation and fertilization. Labeled embryos from the 1‐cell stage to the blastocyst stage were collected, fixed, and autoradiographs of plastic sections prepared. The observed grain density was similar in the pronuclei and in the cytoplasm of 1‐cell embryos. Knowing the volumes of nucleus and cytoplasm, it was determined that 3% of the maternal RNA was found in the pronuclei. It is suggested that some of this nuclear RNA may be stable small nuclear RNAs (e.g. U1 RNA) retained from the germinal vesicle stage through meiotic maturation. During the 2‐cell stage and beyond, maternal RNA is degraded and labeled precursor is reincorporated into nuclear RNA, making it difficult to accurately quantitate the amount of nuclear maternal RNA. It is known that about one third of the total maternal RNA is lost between the 8‐cell and blastocyst stages. It was found that cytoplasmic grain densities in inner and outer cells of the morula and blastocyst were not significantly different. Thus, the loss of maternal RNA does not proceed more rapidly in the differentiating trophoblast than in the inner cell mass.
Relative developmental success of interspecific Lepomis hybrids as an estimate of gene regulatory divergence between species
Authors: Parker Henry R. , Philipp David P. , Whitt Gregory S. 
Published: June 2005

AbstractThe developmental success of interspecific Lepomis hybrids is used as an index of gene regulatory divergence between the green sunfish, L. cyanellus, and each of three other parental species, longear sunfish, L. megalotis, warmouth, L. gulosus, and bluegill, L. macrochirus. This gene regulatory divergence is compared to the degree of structural gene divergence among these four species (genetic distance [Nei, '78], D, ranged from 0.206 to 0.586). The developmental success of the hybrid embryos at the level of morphogenesis was higher than expected from the genetic distance between the parental species. The rates of morphogenesis of the hybrid embryos were the same as that for the green sunfish embryos. The percentage of embryos that hatched was relatively high in all crosses. However, two of the hybrid crosses resulted in enhanced percentages of hatched embryos. Slight increases in the extent of morphological abnormalities were observed in hybrids from crosses between more distantly related parental species.The schedules and levels of enzyme locus expression of the hybrids, assessed spectrophotometrically and electrophoretically for nine enzyme systems (encoded in a total of 14 loci), were different from each other and from those of the green sunfish embryos. Alterations in the time of first enzyme appearance and in the time of first increase in enzyme activity in the developing hybrid embryos were not correlated with genetic distance between parental species. However, the extents of alteration of enzyme activities over the entire period of hybrid embryogenesis were correlated with the genetic distance.We attribute the morphological and molecular anomalies observed in the hybrids to gene regulatory incompatibilities between species. Although the exact number of mutational differences and their relative developmental impacts are not known, some inferences can be drawn about the degree of divergence in gene regulation between species. It appears that an uncoupling of the rates of structural and regulatory gene evolution can occur between species of some taxa, an observation that has implications for the roles of gene regulatory differences in organismic evolution.
On the diversity of sperm histones in the vertebrates: IV. Cytochemical and amino acid analysis in Anura
Authors: Kasinsky H. E. , Huang S. Y. , Mann M. , Roca J. , Subirana J. A. 
Published: June 2005

AbstractThe variability of sperm histones in frogs has been studied by cytochemical and amino acid analyses. Cytochemically, Rana sperm proteins fall into Bloch's ('69, '76) type 4 somatic‐like histone category, while Xenopus and Bufo have type 3 intermediate sperm histones. Extractability in 5% trichloroacetic acid (TCA) at different temperatures splits this type 3 category into two groups: type 3B intermediate sperm histones of Bufo are extractable at 85–90°C, while Xenopus intermediate type 3A sperm histones require temperatures of 95–100°C for extraction. Amino acid analysis confirms that Rana sperm histones are of the nucleosomal type, with a testis‐specific, very lysine‐rich H1 histone. The sperm protein in Bufo is richer in arginine than the proteins in Xenopus. Both of these genera contain lysine and histidine as well as arginine in their sperm proteins. These results confirm earlier electrophetic data (Kasinsky et al., '78) and indicate that sperm histones in the order Anura can vary markedly between different genera.
Effect of forskolin on the spontaneous maturation and cyclic AMP content of hamster oocyte‐cumulus complexes
Authors: Racowsky Catherine 
Published: June 2005

AbstractForskolin, a reversible stimulator of the catalytic subunit of adenylate cyclase, has been used to determine: (1) whether an increase in hamster cumulus cell cyclic adenosine monophosphate (cAMP) results in an elevation of intraoocyte cAMP and an accompanying increase in the maintenance of meiotic arrest (%GV where GV is germinal vesicle) when heterologous coupling is maintained, (2) whether the hamster oolemma possesses the catalytic subunit of adenylate cyclase in an amount adequate to stimulate sufficient cAMP synthesis to maintain arrest, and 3) whether release from meiotic arrest is accompanied by a decrease in the content of intraoocyte cAMP. Intracellular cAMP was determined by RIA, functional metabolic coupling was assessed by determination of the fraction of radiolabeled uridine marker transferred from the cumulus mass to the oocyte, and meiotic stage was determined cytogenetically.While the %GV of both cumulus‐enclosed (intact) and cumulus‐free (denuded) oocytes was dose‐dependent upon forskolin, that of intact oocytes was much more sensitive to the drug (intact: ID50 3.4 μM; denuded: ID50 65.0 μM, where ID50 is the dose of forskolin that inhibits the maturation of 50% of cultured oocytes). Forskolin stimulated a significant, dose‐dependent increase in the amount of cAMP within the cumulus mass [(r) = 0.789, P < 0.001)], the intact oocyte [(r) = 0.715, P < 0.001], and the denuded oocyte [(r) = 0.673, P < 0.01)]. The cAMP content of intact oocytes was significantly greater than that of denuded oocytes above 6.25 μM forskolin (25 μM forskolin: 9.28 ± 1.01 vs. 3.98 ± 0.15 fmol cAMP, intact and denuded oocytes, respectively; P < 0.001, paired t test). A highly significant positive correlation was established between the amount of cAMP in groups of cumulus masses and that in the corresponding enclosed oocytes [(r) = 0.635, P < 0.001]. The enhanced sensitivity of meiotic arrest in intact, as compared to denuded, oocytes was due to the presence of adherent cumulus cells but was not attributable to a significant increase in the cAMP content of intact oocytes (at 6.25 μM forskolin; %GV intact = 73.0 ± 10.7, denuded = 20.3 ± 7.4; fmol cAMP intact = 5.02 ± 1.50; denuded = 4.63 ± 0.81). The arresting action of forskolin on intact oocytes was transient and fully reversible, but release from arrest was not accompanied by a decrease in either intraoocyte cAMP or heterologous metabolic coupling. These data show that (1) the hamster oocyte can synthesize cAMP (2) when heterologous metabolic coupling is maintained cumulus cell cAMP may be transferred to the hamster oocyte, and (3) that release from forskolin‐maintained meiotic arrest is not correlated with a decline in intraoocyte cAMP or in heterologous coupling. The findings indicate that forskolin stimulates hamster cumulus cells to produce a “factor,” which may not be cAMP, to maintain meiotic arrest.
Oxygen consumption of mouse sperm and its relationship to capacitation
Authors: Boell E. J. 
Published: June 2005

AbstractThe oxygen consumption of spermatozoa from the caudae epididymides of the mouse was measured in various media and in the presence or absence of substrates and inhibitory agents in order to investigate the relationship between oxidative metabolism and capacitation.When washed sperm were placed in a medium in which capacitation occurs, respiration increased abruptly, due to the availability of oxidizable substrates, and remained at a high, constant level throughout the period of measurement. There was no temporal change in rate during the time when capacitation was occurring, nor was the rate after capacitation had occurred higher than it was before.Capacitation does not occur in a medium in which polyvinyl alcohol is substituted for bovine serum albumin or to which ethyl alcohol is added. Prevention of capacitation by these means had no effect on the rate of oxygen consumption.The results support the conclusion that the increased respiration of sperm in a capacitating medium is due to the presence of oxidizable substrates and, as such, is an accompaniment of the process of capacitation rather than a factor in bringing it about.
Evidence for the presence and specificity of an unidentified plasma cofactor increasing haemocyanin oxygen affinity in two natantid crustaceans
Authors: Morris S. , Bridges C. R. , Grieshaber M. K. 
Published: June 2005

AbstractInvestigation of haemocyanin oxygen affinity in two species of Palaemon has demonstrated the presence of an unidentified factor (s); (U.F.), in the plasma, that increases oxygen affinity. Plasma exchange experiments have further demonstrated that this factor is not species‐specific and that the magnitude of the effect is dependent on the particular haemocyanin molecule. It has not been possible to demonstrate conclusively that the effect of this factor(s) can be reduced by dilution of the plasma. The variability in the extent of this cofactor effect, throughout the Crustacea, may be explained by variable sensitivity of haemocyanin to U.F.
Blood viscosity in arctic fishes
Authors: Graham Mark S. , Fletcher Garth L. , Haedrich Richard L. 
Published: June 2005

AbstractThe blood viscosity of arctic char, Salvelinus alpinus, and shorthorn sculpin, Myoxocephalus scorpius, from the arctic (74° 42′N) was measured with a cone‐plate viscometer. Blood viscosity of the two arctic species was considerably lower, less shear rate dependent, and less temperature dependent than the blood of winter flounder (Pseudopleuronectes americanus) from more temperate waters. The rheological properties of the arctic fish blood would minimize blood flow resistance and thus be advantageous at the low temperatures (0°C) characterizing their environment.
Isolation of enamelinlike proteins from blue shark (Prionace glauca) enameloid
Authors: Graham Edward Earl 
Published: June 2005

AbstractA sequential dissociative extraction scheme was used to extract proteins from developing Blue Shark enameloid. The first extraction solution (4 M guanidine HCl) solubilized the polypeptides, mainly collagenous, not closely associated with the hydroxyapatite. The next extraction solution (4 M guanidine HCl, 0.5 M ethylenediaminetetraacedic acid (EDTA)) solubilized the proteins more closely associated with the tooth mineral component. After extraction, the proteins were separated and isolated with gel electrophoresis. Protein molecular weights were determined and selected proteins were isolated for amino acid composition analysis. The two proteins isolated were tested for mammalian enamel protein antigenic determinants by a “Dot” immunobinding assay. The isolated proteins were enamelinlike by extraction criteria and amino acid composition. Further, the two proteins share antigenic determinants with mammalian enamel proteins.
Photoperiodic regulation of thyroid responsiveness to TSH in Fundulus heteroclitus
Authors: Grau E. Gordon , Brown Christopher L. , Stetson Milton H. 
Published: June 2005

AbstractTreatment of the killifish, Fundulus heteroclitus, with ovine thyrotropin (oTSH) produced elevations in serum thyroxin (T4) that varied seasonally with a strong inverse correlation to environmental photoperiod (P < 0.001). At 20°C, oTSH (0.2 IU) increased serum T4 to levels ranging from 1.5 μg/100 ml in midsummer to 7.5 μg/100 ml in midwinter despite relatively stable resting levels throughout the two years of study. Similar rates of clearance of T4 in summer and winter suggest that an alteration in thyroid response to oTSH accounts for this change. The serum T4 response to oTSH is both photoperiod‐ and temperature‐dependent. In laboratory studies, fish exposed to a short artificial photoperiod (LD 8:16) for one month responded to oTSH with T4 levels about twice as high as those in fish exposed to long days (LD 14:10). On the other hand the T4 response to oTSH was sharply reduced at 5°C from that seen at 20°C. This suggests that, in nature, seasonal changes in photoperiod and temperature have opposite effects on thyroidal responsiveness to TSH. Overall, the annual variation in the T4 response to oTSH appears to be driven by photoperiod, inasmuch as the alterations preceded major temperature changes in the wild and can be shown to occur at constant temperature in captivity. Photoperiodic induction of changes in thyroid sensitivity may aid in the maintenance of basal T4 levels under changing thermal conditions.
Surface of the rooster spermatozoon changes in passing through the Wolffian duct
Authors: Esponda P. , Bedford J. M. 
Published: June 2005

AbstractFluid secreted by the rooster Wolffian duct contains several proteins separable on polyacrylamide gel electrophoresis (PAGE) and isoelectricfocusing (IEF) gels. Antibodies against these fluid components were obtained by immunizing rabbits, and the IgG fraction was then purified. As judged by indirect immunofluorescence, purified IgG against rooster duct fluid did not bind to any testicular spermatozoa. However, it bound distinctly to the whole surface of spermatozoa from the initial (epididymal) region and more intensely to all spermatozoa from the mid‐ and terminal regions of the Wolffian duct of the rooster, though not at all to mature duck or pigeon spermatozoa. Thus, in the rooster, as in therian mammals, the surface of the spermatozoon clearly acquires specific components secreted by the Wolffian duct. It should not be assumed that such surface change in rooster spermatozoa is entirely comparable, in a functional sense, to that undergone by mammalian spermatozoa, in which this seems directly related to fertilizing ability. Unlike those of mammals, rooster spermatozoa do not seem to require capacitation, and some spermatozoa in the testis already are competent to fertilize. Components acquired in the Wolffian duct by the rooster spermatozoon may bear on other aspects, perhaps sperm transport and/or survival in the female.
Stimulating male sexual behavior with repetitive pulses of GnRH in female green iguanas, Iguana iguana
Authors: Phillips John A. , Alexander N. , Karesh William B. , Millar R. , Lasley B. L. 
Published: June 2005

AbstractAdult female green iguanas (Iguana iguana) were treated with repetitive pulses of chicken gonadotropin (d‐Arg6 chicken II) releasing hormone (GnRH) delivered by interperitoneal osmotic pumps. Total estrogen levels in serum decreased from 37.3 ± 18.0 pg/ml to 5.4 ± 4.6 pg/ml 9 days after the pump was implanted. Estrogen levels returned to pre‐implant levels 5 days after the end of the treatment period. The behavior of male iguanas, housed with the treated females, was influenced while the pumps were functioning. The frequency of assertive displays between males increased threefold after 7 days of GnRH treatment. Males actively interposed themselves between “their” female and other males during the same period.
Exogenous catecholamines do not affect osmoregulatory parameters in the intact eel
Authors: Epple August , Kahn Harry A. 
Published: June 2005

AbstractInjections of physiological (2 μg/kg) and supraphysiological (8 μg/kg) doses of dopamine, norepinephrine, and epinephrine via a cardiac cannula into freshwater‐adapted eels were not followed by changes in serum osmolality, sodium, and chloride. Likewise, injections of 8 μg/kg of epinephrine had no impact on these parameters in seawater‐adapted eels. These results suggest that circulating catecholamines do not have a major effect on the overall balance of osmoregulatory serum components in the intact eel.
Adrenergic responses of the cardiovascular system of the eel, Anguilla australis, in vivo
Authors: Hipkins Scott F. 
Published: June 2005

AbstractHeart output, arterial pressures, and heart rate were measured directly in conscious unrestrained eels (Anguilla australis) and responses to intra‐arterial injection of adrenaline monitored. Adrenaline increased systemic vascular resistance, heart output, and cardiac stroke volume in all animals. In some cases small transient decreases in stroke volume and hence heart output were seen at the peak of the pressor response: These probably reflect a passive decrease in systolic emptying due to increased afterload on the heart. In most cases, adrenaline produced tachycardia; but two animals showed consistent and profound reflex bradycardia, which was accompanied by a concomitant increase in stroke volume such that heart output was maintained or increased slightly. The interaction of changes in heart output and systemic vascular resistance produced complex and variable changes in arterial pressure. There was no consistent pattern of changes in branchial vascular resistance. Atropine treatment in vivo revealed vagal cardio‐inhibitory tone in some animals and always blocked the reflex bradycardia seen during adrenaline induced hypertension. In some animals, adrenaline injection after atropine pretreatment led to the establishment of cyclic changes in arterial pressure with a period of about 1 min (Mayer waves).
Effects of pH on in vitro ovulation of goldfish (Carassius auratus) oocytes
Authors: Goetz Frederick W. , Nagahama Yoshitaka 
Published: June 2005

AbstractThe in vitro effects of pH on goldfish (Carassius auratus) ovulation were investigated. Final oocyte maturation and follicular detachment were induced in vivo in gravid goldfish by HCG injections and elevated holding temperatures. Females were biopsied to determine the time of germinal vesicle breakdown and when oocytes should be removed for in vitro incubations. Prior to ovulation, the ovaries were removed, dissected and mature intrafollicular oocytes were incubated in media of varying pH (7.3–8.9). There was a significant increase in ovulation as the pH of the incubation increased and this ovulation could be blocked by indomethacin. Indomethacin did not inhibit the actual mechanism of oocyte expulsion since exogenous PGF2α induced ovulation in indomethacin blocked incubates. Increased pH did not increase the ovulatory response observed with exogenous PGF2α. The combined results suggest that an increase in incubation pH stimulates prostaglandin synthesis that, in turn, stimulates ovulation.