bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oocyte maturation in rabbits: effects of calmodulin inhibitors
Authors: Henry Michael A. , Rawlins Richard G. , Radwanska Ewa , Fahy Mary M. 
Published: September 2008

SummaryOocyte maturation in mammals follows a highly conserved pattern of release from arrest through to the extrusion of the first polar body and formation of the second metaphase spindle. Oscillations in cytoplasmic calcium concentration precede the events of maturation in many species. These calcium ions interact with and activate calcium-binding proteins, including calmodulin, within the cell. Thus, it was of interest to us to examine whether calcium acted through calmodulin in the initial stages of maturation in rabbit oocytes or whether calmodulin was required for continuation through metaphase I on to metaphase II. Using the calmodulin inhibitor W-7 we found a significant (p< 0.05) decrease in the percentage of oocytes that underwent germinal vesicle breakdown. Calmidazolium did not prevent germinal vesicle breakdown; however, it caused a significant (p< 0.05) decrease in the proportion of oocytes with fully elaborated spindles and taxol-induced cytoplasmic asters. Both inhibitors caused a significant (p< 0.05) reduction in the proportion of oocytes that extruded their first polar bodies. The kinase inhibitor 6-DMAP caused a significant reduction in the proportion of oocytes with spindles and condensed chromatin, indicating the necessity for phosphorylation events in the resumption of meiosis. In rabbit oocytes calmodulin may play a role in the release from prophase arrest, and it is necessary for spindle preservation and continuation through metaphase I to metaphase II. The varying effects of the two inhibitor stems from their different binding sites on the calmodulin molecule thus causing a differential effect on its downstream effectors.
Caprine blastocyst formation following intracytoplasmic sperm injection and defined culture
Authors: Keskintepe L. , Morton P.C. , Smith S.E. , Tucker M.J. , Simplicio A.A. , Brackett B.G. 
Published: September 2008

SummaryExperiments were undertaken to develop intracytoplasmic sperm injection (ICSI) to produce caprine embryos out of the normal breeding season. Oocytes were obtained from 2–6 mm ovarian follicles at slaughter. Selected oocytes with two to four layers of cumulus cells were incubated in 1 ml of H-TCM 199 supplemented with 10 μg each of oFSH and bLH (NHPP, NIDDK, NICHD, USDA) and 20% fetal bovine serum (FBS) in a thermos (38.5°C) for 4.5 h during transportation. Then, oocytes were transferred into 75 μl of freshly prepared maturation medium under paraffin oil and a mixture of 5% O2, 5% CO2 and 90% N2. Approximately 26 h after recovery oocytes were denuded by incubation with hyaluronidase (100 IU/ml) and pipetting and held at 38.5°C for 90 min. Spermatozoa frozen in egg yolk extender were thawed in a 37°C water bath for 15s. Motile fractions were selected by swim-up, then incubated for 90 mm in TALP with 10 μg heparin/ml. Each oocyte was positioned with its first polar body at 6 or 12 o'clock by a holding pipette. Sperm (1 μl) were added to 10 μl medium containing 10% polyvinylpyrrolidone. A sperm cell was aspirated into a pipette, and then injected head-first into the cytoplasm of an oocyte maintained in H-TCM 199 + 20% FBS at 37°C. Injected oocytes were transferred to HM and, after 90 min, cultured in 50 μl of BSA-free synthetic oviduct fluid plus polyvinyl alcohol, citrate and non-essential amino acids. Results demonstrate that caprine blastocysts can be produced outside the breeding season by the use of frozen-thawed semen and injection of sperm cells with broken tails into ova followed by culture in defined medium.
Effect of inhibitors of DNA replication on early zebrafish embryos: evidence for coordinate activation of multiple intrinsic cell-cycle checkpoints at the mid-blastula transition
Authors: Ikegami Richard , Rivera-Bennetts Alma K. , Brooker Deborah L. , Yager Thomas D. 
Published: September 2008

SummaryWe address the developmental activation, in the zebrafish embryo, of intrinsic cell-cycle checkpoints which monitor the DNA replication process and progression through the cell cycle. Eukaryotic DNA replication is probably carried out by a multiprotein complex containing numerous enzymes and accessory factors that act in concert to effect processive DNA synthesis (Applegren, N.et al.(1995)J. Cell. Biochem.59, 91–107). We have exposed early zebrafish embryos to three chemical agents which are predicted to specifically inhibit the DNA polymerase α, topoisomerase I and topoisomerase II components of the DNA replication complex. We present four findings: (1) Before mid-blastula transition (MBT) an inhibition of DNA synthesis does not block cells from attempting to proceed through mitosis, implying the lack of functional checkpoints. (2) After MBT, the embryo displays two distinct modes of intrinsic checkpoint operation. One mode is a rapid and complete stop of cell division, and the other is an ‘adaptive’ response in which the cell cycle continues to operate, perhaps in a ‘repair’ mode, to generate daughter nuclei with few visible defects. (3) The embryo does not display a maximal capability for the ‘adaptive’ response until several hours after MBT, which is consistent with a slow rranscriptional control mechanism for checkpoint activation. (4) The slow activation of checkpoints at MBT provides a window of time during which inhibitors of DNA synthesis will induce cytogenetic lesions without killing the embryo. This could be useful in the design of a deletion-mutagenesis strategy.
Fate of microinjected sperm components in the mouse oocyte and embryo
Authors: Cummins James M. , Wakayama Teruhiko , Yanagimachi Ryuzo 
Published: September 2008

SummaryIntact mouse sperm or mouse sperm tails alone, labelled with MitoTracker Green FM® fluorochrome, were injected into mouse oocytes and the cells cultured in vitro for up to 5 days. The dye stained midpiece mitochondria, the sperm tail coarse fibres and the sperm perforatorium. Intact sperm (or tails injected with separated heads) induced normal embryonic development. The mitochondria could be identified in embryos up to the 4-cell stage, remaining associated with the sperm tail. They largely disappeared by the 8-cell stage, when only a minority of embryos (6/43) could be found with small patches of mitochondria. Axonemal elements could be identified coiled up in single external blastomeres as late as day 5 blastocysts. By contrast, mitochondria as well as tail components could be identified up to 5 days after injection of sperm tails alone into non-activated oocytes and also in embryos that arrested development before the 8-cell stage. We conclude that disappearance of the labelled sperm mitochondria in normally cleaving embryos is not due to fading or inactivation of the fluorochrome marker, but is rather an event specifically tied to cell cycle activities around the second cell division.
Expression of Fas–Fas ligand system associated with atresia in murine ovary
Authors: Ping Xu Ji , Li Xiang , Mori Etsuko , Sato Eimei , Saito Shigeru , Guo Mao Wu , Mori Tsuneatsu 
Published: September 2008

SummaryWe detected that Fas receptor (Fas) was expressed at transcriptional levels in oocytes/eggs and some granulosa cells of murine ovary, whereas, Fas ligand (FasL) was found to be strongly expressed in granulosa cells by means ofin situhybridisation. These results were supported by an indirect immunofluorescence (IIF) test with anti-Fas monoclonal antibody (mAb)/FasL Ab. The lysates from granulosa cells were precipitated by anti-FasL Ab, exhibiting a specific band at 40 kDa. When zona pellucida (ZP)-free eggs were incubated with granulosa cellsin vitro, apoptosis (DNA fragmentation) was induced in the eggs, as detected by the terminal deoxynucleotide transferase mediated dUTP-nick end labelling (TUNEL) method. To examine whether FasL-bearing cells can induce apoptosis in eggs expressing Fas through molecular interaction between FasL and Fas, we employed a baculovirus expression system to generate FasL on the surface ofSpodoptera frugiperda(Sf9) cells. The co-incubation of eggs withAutographa californicanuclear polyhedrosis virus (AcNPV) and FasL transfected Sf9 (Sf9–FasL) cellsin vitrowas performed and resulted in the induction of apoptosis in eggs as detected by the TUNEL method. Apoptosis was absent in eggs co-incubated with AcNPV-1393 transfected Sf9 (Sf9−1393) cells. Thus, ovarian atresia was suggested to be induced by molecular interaction between FasL on granulosa cells and Fas on oocytes/eggs during oogenesis.
Activation of the metaphase checkpoint and an apoptosis programme in the early zebrafish embryo, by treatment with the spindle-destabilising agent nocodazole
Authors: Ikegami Richard , Zhang Jianshe , Rivera-Bennetts Alma K. , Yager Thomas D. 
Published: September 2008

SummaryWe have studied the developmental activation of the metaphase checkpoint, and the consequences of activating this checkpoint, in the zebrafish embryo. (1) Treatment with nocodazole (a microtubule destabiliser) before mid-blastula transition (MBT) produces complete destruction of all nuclei in the deep cell layer of the embryo. In contrast, nocodazole treatment after MBT efficiently produces metaphase arrest in this cell layer. Thus, the metaphase checkpoint becomes activated at MBT. (2) Although a metaphase arrest is induced by nocodazole, it is not induced by paclitaxel (a microtubule stabiliser). Thus the metaphase checkpoint appears to sense a destabilisation, but not a stabilisation, of spindle microtubules. (3) Metaphase-arrested cells (in nocodazole) can be driven into the next interphase by adding the Ca2+-specific ionophore A23187. Thus, a Ca2+-signalling pathway lies downstream of, or parallel to, the metaphase checkpoint. (4) After mid-gastrula stage, treatment with nocodazole produces DNA fragmentation in all three cell layers. In the enveloping epithelial monolayer (EVL), this is associated with a classical apoptotic phenotype. In the deep layer, it is associated with an unusual, highly condensed nuclear state that is entered directly from metaphase arrest. Thus, after the mid-gastrula stage, the embryo responds to nocodazle by undergoing apoptosis. (5) Nocodazole-induced apoptosis in the deep cell layer can be blocked by the caspase-1,4,5 inhibitors Ac-YVAD-CHO and Ac-YVAD-CMK. This suggests that a homologue of theC. elegans ced-9—ced-4—ced-3pathway is involved in control over apoptosis in the early zebrafish embryo.
Distribution of cortical granules in bovine oocytes classified by cumulus complex
Authors: Hosoe M. , shioya Y. 
Published: September 2008

SummaryThe present study was conducted to examine distributional changes of cortical granules(CGs)during meitotic maturation and fetilisation in vitro and the developmental ability in bovine oocytes classified by cumulus cells. The oocytes were classified by the morphology if their cumulus cell layers as follows: class A, compact and thick; class B, compact but thin; class C, naked; and class D, expanded. some of the oocytes were stained with Lens curinalis agglutinin(LCA) before and after maturation in vitro and after insemination, and then stained with orcein to observe their nuclear stages. The others were left in culture. Distributional patterns of the CGs were classified into four types: type I, CGs distributed in clusters; type II, CGs dispersed and partly clustered; type III, all CGs dispersed; and type IV, no CGs Most of the oocytes before culture showed a type I pattern, but this decreased after maturation culture, whereas type III increased in class A. The oocytes of class B showed similar changes while the oocytes of class C did not. In class C, many oocytes showed type I after culture indicating that cytoplasmic maturation was not completed. IN class D, 80.4% of the oocytes exhibited types III before maturation culture, indicating that their cytoplasmic maturation was different from classes A–C. and about 70% of the class D oocytes were at the unclear stage of germinal vesicle breakdown(GVBD) before culture. The developmental rates to blastocysts in classes A–D were 28.7%, 23.1%, 0.5% and 3.4% respectively.
Spatial distribution of Bacteria and Archaea and amoA gene copy numbers throughout the water column of the Eastern Mediterranean Sea
Authors: De Corte Daniele , Yokokawa Taichi , Varela Marta M , Agogué Hélène , Herndl Gerhard J 
Published: September 2008

Abstract
Until recently, ammonia oxidation, a key process in the global nitrogen cycle, was thought to be mediated exclusively by a few bacterial groups. It has been shown now, that also Crenarchaeota are capable to perform this initial nitrification step. The abundance of ammonia oxidizing Bacteria and Archaea was determined using the bacterial and archaeal ammonia monooxygenase-α subunit (amoA) gene as functional markers in a quantitative PCR approach and related to the abundance of Bacteria and Archaea in the Eastern Mediterranean Sea. Archaeal amoA copy numbers decreased from 4000–5000 copies ml−1 seawater from the 200–500 m depth layer to 20 copies ml−1 at 1000 m depth. β-Proteobacterial amoA genes were below the detection limit in all the samples. The archaeal amoA copy numbers were correlated with NO2− concentrations, suggesting that ammonia-oxidizing Archaea may play a significant role in the nitrification in the mesopelagic waters of the Eastern Mediterranean Sea. In the bathypelagic waters, however, archaeal amoA gene abundance was rather low although Crenarchaeota were abundant, indicating that Crenarchaeota might largely lack the amoA gene in these deep waters. Terminal restriction fragment length polymorphism analysis of the archaeal community revealed a distinct clustering with the mesopelagic community distinctly different from the archaeal communities of both, the surface waters and the 3000–4000 m layers. Hence, the archaeal community in the Eastern Mediterranean Sea appears to be highly stratified despite the absence of major temperature and density gradients between the meso- and bathypelagic waters of the Mediterranean Sea.
Verbal Working Memory and Story Retelling in School-Age Children With Autism
Authors: Gabig Cheryl Smith 
Published: September 2008

Purpose
This study examined verbal working memory and language ability in 15 school-age children with autism using 3 verbal working memory tasks and 1 story recall task.

Method

Three measures of verbal working memory—nonword repetition, memory for digits span, and sentence imitation—were given to children with autism and age-matched controls. Verbal working memory measures were chosen to reflect increasing levels of cognitive–linguistic complexity. Story retelling was measured using
The
Renfrew Bus Story
(J. Cowley & C. Glasgow, 1994) and was scored for the percentage of propositions recalled and the average utterance length.

Results
A profile of verbal working memory deficits was seen in children with autism, with poorer performance on more complex verbal memory tasks. Performance on the 3 verbal memory tasks was independent of articulation ability. For the group with autism, receptive vocabulary was associated with sentence imitation and story recall but not with nonword repetition or digits span. Sentence imitation was related to story recall, but the relationship disappeared when the effect of vocabulary was removed.

Conclusions

Vocabulary and language processing demands affect the performance of children with autism on tasks of verbal memory and story retelling. Results are viewed within a
connectionist
framework of verbal working memory
.
The Effect of Classroom Amplification on the Signal-to-Noise Ratio in Classrooms While Class Is in Session
Authors: Larsen Jeffery B. , Blair James C. 
Published: September 2008

Purpose
The purpose of this study was to measure the signal-to-noise ratios in classrooms while class was in session and students were interacting with the teacher and each other.

Method
Measurements of noise and reverberation were collected for 5 different classrooms in 3 different schools while class was in session. Activities taking place during the measurements were recorded to compare with sound level measures. The use of infrared classroom amplification was compared with no amplification.

Results/Conclusion
The results revealed that when classroom amplification was used, students heard the teacher’s voice at a level that was an average of 13 dB above the noise floor as compared to an average of +2 dB above the noise floor without amplification.
The effects of perceived parenting style on the propensity for illicit drug use: the importance of parental warmth and control
Authors: MONTGOMERY CATHARINE , FISK JOHN E. , CRAIG LAURA 
Published: September 2008

AbstractIntroduction and Aims. Research in adolescents has shown that parental warmth and control are important factors in drug use. The present study focused upon investigating perceived parental warmth and control in a sample of post‐adolescent ecstasy/polydrug users, and investigating their relationship to severity of drug use. Design and Methods. A total of 128 (65 male) ecstasy/polydrug users, 51 (17 male), cannabis‐only users and 54 (13 male) non‐users were recruited from a university population. All participants completed the parenting styles and drug use questionnaires. Results. Compared to non‐users, a greater proportion of ecstasy/polydrug users characterised their parents' style as neglectful. The modal style endorsed by non‐users was authoritative. Those who rated their parents' style as authoritative had significantly lower lifetime consumption and average dose of ecstasy relative to those describing their parents as neglectful. Again, relative to those describing their parents as neglectful, participants from authoritarian backgrounds had significantly smaller lifetime consumption of ecstasy and cocaine and significantly smaller average doses of cannabis, ecstasy and cocaine. Contrary to expectation, there was no significant association between perceived parental warmth and the severity of ecstasy use. Discussion and Conclusions. The present study is, to our knowledge, the first to quantify drug use, and relate it to perceived parental practices in a post‐adolescent sample of ecstasy/polydrug users. The results provide further support for the relationship between perceived parental control and drug use.
Bicoherence during confinement transitions in the TJ-II stellarator
Authors: van Milligen B.Ph. , Kalhoff T. , Pedrosa M.A. , Hidalgo C. 
Published: September 2008

Bicoherence was computed for a number of discharges having confinement transitions, either induced by biasing or spontaneous, at the TJ-II stellarator. The bicoherence was computed for a variety of signals obtained using a reciprocating Langmuir probe system, but the main emphasis here is on the analysis of the poloidal electric field (E
θ).
During biasing, the auto-bicoherence of E
θ was significant only in a narrow radial range, in contrast to the fluctuation level of E
θ and the linear coherence between E
θ and E

r
(the radial electric field), which were affected over a very broad radial extension.
With spontaneous transitions, significant bicoherence was again detected only in a narrow radial range, associated with the position of the flow shear layer. The observations are consistent with the standard sheared flow model for confinement transitions.
The temporal asymmetry A of E
θ was also computed. During biasing, the region of strongly modified asymmetry was located inwards from the bicoherence maximum. This suggests that the detected bicoherence is not merely due to a change in the temporal shape of the signal.
Characterization of expressed sequence tags from turkey skeletal muscle
Authors: Reed K. M. , Mendoza K. M. , Juneja B. , Fahrenkrug S. C. , Velleman S. , Chiang W. , Strasburg G. M. 
Published: September 2008

SummaryThis study was designed to identify important muscle gene homologues in the turkey. Three skeletal muscle cDNA libraries representing distinct muscle developmental stages were constructed. A total of 20 042 clones were sequenced resulting in 13 023 finished high‐quality sequences (trimmed, quality scored and masked) for analysis. Sequence clustering produced 1113 contigs and 4144 singletons (5257 putative transcripts). Sequences were compared by blastn to the chicken whole‐genome sequence and to the Ensembl and NCBI databases to identify homologous sequences. These surveys indicated that most of the important muscle genes are included in the sequence collection. Examination of contigs identified 1288 single nucleotide polymorphisms and in 320 of those the minor allele was observed to be present in more than one sequence. This resource provides sequence variants for numerous genes in the turkey, as demonstrated by the SNP haplotypes that were constructed for 10 genes. Sequences obtained in this study provide the basis for constructing a skeletal muscle‐focused microarray, a tool that will facilitate the analysis of genes expressed during turkey muscle development, as well as the expression of genes underlying the genetic basis of muscle characteristics associated with meat quality.
Polymorphisms in eggshell organic matrix genes are associated with eggshell quality measurements in pedigree Rhode Island Red hens
Authors: Dunn I. C. , Joseph N. T. , Bain M. , Edmond A. , Wilson P. W. , Milona P. , Nys Y. , Gautron J. , Schmutz M. , Preisinger R. , Waddington D. 
Published: September 2008

SummaryNovel and traditional eggshell quality measurements were made from up to 2000 commercial pedigree hens for a candidate gene association analysis with organic eggshell matrix genes: ovocleidin‐116, osteopontin (SPP1), ovocalyxin‐32 (RARRES1), ovotransferrin (LTF), ovalbumin and ovocalyxin‐36, as well as key genes in the maintenance and function of the shell gland [estrogen receptor (ESR1) and carbonic anhydrase II (CAII)]. Associations were found for (i) ovalbumin with breaking strength and shell thickness; (ii) ovocleidin‐116 with elastic modulus, shell thickness and egg shape; (iii) RARRES1 with mammillary layer thickness; (iv) ESR1 with dynamic stiffness; (v) SPP1 with fracture toughness and (vi) CAII with egg shape. The marker effects are as large as 17% of trait standard deviations and could be used to improve eggshell quality.