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121.
The objective of this study was to examine the effect of cytochalasin B (CB) and/or demecolcine (Dc) on the remodeling of donor nuclei, nuclear ploidy, and development of somatic cell nuclear transfer (SCNT) and parthenogenetic (PA) pig embryos. SCNT and PA oocytes were either untreated (control), or treated with CB, Dc, or both CB and Dc after electric activation, and then cultured or transferred to surrogates. In SCNT, blastocyst formation was higher after treatment with CB and/or Dc (26–28%) than in the controls (16%). The number of oocytes that formed a single pronucleus (PN) was higher after treatment with Dc (86%) and CB + Dc (86%) than under control conditions (44%) or after treatment with CB (63%). In PA, blastocyst formation was higher after CB treatment (47%) than under control conditions (28%), while the formation of a single PN was higher after treatment with Dc (88%) and CB + Dc (84%) compared to controls (34%). The rate of formation of diploid embryos was higher after treatment with Dc and CB + Dc than under control conditions. Dc treatment resulted in a farrowing rate of 50% with 1.1% production efficiency, while controls showed a farrowing rate of 37.5% and a production efficiency of 0.7%. The results of our study demonstrate that post‐activation treatment with Dc improves preimplantation development and supports normal in vivo development of SCNT pig embryos, probably because Dc induces formation of a single PN and this leads to normal nuclear ploidy. Mol. Reprod. Dev. 76: 611–619, 2009. © 2008 Wiley‐Liss, Inc.  相似文献   
122.
Vertebrate oocytes awaiting fertilization are arrested at metaphase of meiosis II by cytostatic factor (CSF). This arrest is due to inhibition of the anaphase-promoting complex/cyclosome, in part by a newly identified protein, Emi2 (xErp1). Emi2 is required for maintenance of CSF arrest in egg extracts, but its function in CSF establishment in oocytes and the normal embryonic cell cycle is unknown. Here we show that during oocyte maturation, Emi2 appears only after metaphase I, and its level peaks at CSF arrest (metaphase II). In M phase, Emi2 undergoes a phosphorylation-dependent electrophoretic shift. Microinjection of antisense oligonucleotides against Emi2 into stage VI oocytes blocks progression through meiosis II and the establishment of CSF arrest. Recombinant Emi2 rescues CSF arrest in these oocytes and also causes CSF arrest in egg extracts and in blastomeres of two-cell embryos. Fertilization triggers rapid, complete degradation of Emi2, but it is resynthesized in the first embryonic cell cycle to reach levels 5-fold lower than during CSF arrest. However, depletion of the protein from cycling egg extracts does not prevent mitotic cell cycle progression. Thus, Emi2 plays an essential role in meiotic but not mitotic cell cycles.  相似文献   
123.
Hunter-gatherers living in Europe during the transition from the late Pleistocene to the Holocene intensified food acquisition by broadening the range of resources exploited to include marine taxa. However, little is known on the nature of this dietary change in the Mediterranean Basin. A key area to investigate this issue is the archipelago of the Ègadi Islands, most of which were connected to Sicily until the early Holocene. The site of Grotta d’Oriente, on the present-day island of Favignana, was occupied by hunter-gatherers when Postglacial environmental changes were taking place (14,000-7,500 cal BP). Here we present the results of AMS radiocarbon dating, palaeogenetic and isotopic analyses undertaken on skeletal remains of the humans buried at Grotta d’Oriente. Analyses of the mitochondrial hypervariable first region of individual Oriente B, which belongs to the HV-1 haplogroup, suggest for the first time on genetic grounds that humans living in Sicily during the early Holocene could have originated from groups that migrated from the Italian Peninsula around the Last Glacial Maximum. Carbon and nitrogen isotope analyses show that the Upper Palaeolithic and Mesolithic hunter-gatherers of Favignana consumed almost exclusively protein from terrestrial game and that there was only a slight increase in marine food consumption from the late Pleistocene to the early Holocene. This dietary change was similar in scale to that at sites on mainland Sicily and in the rest of the Mediterranean, suggesting that the hunter-gatherers of Grotta d’Oriente did not modify their subsistence strategies specifically to adapt to the progressive isolation of Favignana. The limited development of technologies for intensively exploiting marine resources was probably a consequence both of Mediterranean oligotrophy and of the small effective population size of these increasingly isolated human groups, which made innovation less likely and prevented transmission of fitness-enhancing adaptations.  相似文献   
124.
Bio‐economy and human being A widely accepted vision is a prerequisite for an effective prevention and successful overcoming of inevitable acceptance problems during the implementation process of a bio‐economy strategy. The best biotech / bio‐economic innovation can not be implemented in a welfare enhancing way, if the following conditions are not met: 1) innovation‐related, normative issues have to be already discussed at the societal level before or during the development of innovations, 2) the associated risks and opportunities are identified and communicated and 3) strategies to avoid these risks are developed. All this requires participation of the affected societal groups along with effective communication strategies.  相似文献   
125.
The formation mechanism of Maillard peptides was explored in Maillard reaction through diglycine/glutathione(GSH)/(Cys‐Glu‐Lys‐His‐Ile‐Met)–xlyose systems by heating at 120 °C for 30–120 min. Maximum fluorescence intensity of Maillard reaction products (MRPs) with an emission wavelength of 420~430 nm in all systems was observed, and the intensity values were proportional to the heating time. Taken diglycine/GSH–[13C5]xylose systems as a control, it was proposed that the compounds with high m/z values of 379 and 616 have the high molecular weight (HMW) products formed by cross‐linking of peptides and sugar. In (Cys‐Glu‐Lys‐His‐Ile‐Met)–xylose system, the m/z value of HMW MRPs was not observed, which might be due to the weak signals of these products. According to the results of gel permeation chromatography, HMW MRPs were formed by Maillard reaction, especially in (Cys‐Glu‐Lys‐His‐Ile‐Met)–xylose system, the percentage of Maillard peptides reached 52.90%. It was concluded that Maillard peptides can be prepared through the cross‐linking of sugar and small peptides with a certain MW range. Copyright © 2012 European Peptide Society and John Wiley & Sons, Ltd.  相似文献   
126.
With the purpose of assessing the status of dormancy in seeds of two Begonia species (Begonia lithophila and Begonia guishanensis), freshly matured seeds were given gibberellic acid and moist chilling and allowed to dry after ripening. The seeds were then germinated on media with or without KNO3 at 15, 20, 25, 30 and 18/25°C. All three treatments significantly increased germination percentages. Examination by X‐ray revealed that seeds of both species have a fully developed embryo and thus have no morphological component of dormancy; seeds readily imbibed water and KNO3 solution. Therefore, we conclude that seeds of the two Begonia species have non‐deep physiological dormancy. Although KNO3 significantly increased germination in both species, alternating temperatures did not, suggesting that the most favorable microhabitat for germination is small‐scale disturbances under the forest canopy.  相似文献   
127.
Aquaporin-4 (AQP-4), the most important water channel in the brain, is expressed by astrocyte end feet abutting microvessels. Altered expression levels of AQP-4 and redistribution of the protein throughout the membranes of cells found in glioblastoma multiforme (GBM) lead to development of the edema often found surrounding the tumor mass. Dysregulation of AQP-4 also occurs in hippocampal sclerosis and cortical dysplasia in patients with refractory partial epilepsy. This work reports on analysis of the relationship between AQP-4 expression and the incidence of epileptic seizures in patients with GBM. Immunohistochemical and polymerase chain reaction techniques were used to evaluate AQP-4 in biopsy specimens from 19 patients with GBM, 10 of who had a history of seizures before surgery. AQP-4 mRNA levels were identical in the two groups of patients, but AQP-4 expression was more frequently detected on the GBM membranes from specimens of patients with seizures than from individuals without (10 versus 2, P < 0.001). We conclude that reduced expression of cell surface AQP-4 is characteristic of GBM patients without seizures, likely attributable to a posttranslational mechanism.  相似文献   
128.
A high‐performance liquid chromatography (HPLC) method was established to detect Xeljanz enantiomers in active pharmaceutical ingredients (APIs) and tablets. The separation was achieved on a Chiralpak IC column using a mobile phase of hexane‐ethanol‐diethylamine (65:35:0.1, v/v). The detection wavelength was 289 nm. The peak areas and the enantiomer concentrations in the range of 0.15–2.25 μg?mL?1 were in high linearity, with correlation coefficients higher than 0.999. The recoveries were 86.44% at the concentrations of 7.5, 18.75, and 37.5 μg?mL?1. The limit of detection (LOD) and limit of quantification (LOQ) were 0.042 and 0.14 μg?mL?1, respectively. This HPLC method is suitable for detecting the enantiomers of Xeljanz in its APIs and tablets. Chirality 27:235–238, 2015. © 2014 Wiley Periodicals, Inc.  相似文献   
129.
The contemporary distribution and genetic structure of a freshwater fish provide insight into its historical geodispersal and geographical isolation following Quaternary climate changes. The short ninespine stickleback, Pungitius kaibarae, is a small gasterosteid fish occurring in freshwater systems on the Korean Peninsula and in southeast Russia. On the Korean Peninsula, P. kaibarae populations are distributed in three geographically separated regions: the NE (northeast coast), SE (southeast coast), and a limited area in the ND (Nakdong River). In this study, we used mitochondrial loci and microsatellites to investigate the evolutionary history of P. kaibarae populations by assessing their pattern of genetic structure. Our analyses revealed a marked level of divergence among three regional populations, suggesting a long history of isolation following colonization, although ND individuals showed relatively higher genetic affinity to populations from SE than those from NE. The populations from NE showed a great degree of interpopulation differentiation, whereas populations from SE exhibited only weak genetic structuring. Upon robust phylogenetic analysis, P. kaibarae formed a monophyletic group with Russian P. sinensis and P. tymensis with strong node confidence values, indicating that P. kaibarae populations on the Korean Peninsula originated from the southward migration of its ancestral lineage around the middle Pleistocene.  相似文献   
130.
The analysis of sequence conservation is commonly used to predict functionally important sites in proteins. We have developed an approach that first identifies highly conserved sites in a set of orthologous sequences using a weighted substitution‐matrix‐based conservation score and then filters these conserved sites based on the pattern of conservation present in a wider alignment of sequences from the same family and structural information to identify surface‐exposed sites. This allows us to detect specific functional sites in the target protein and exclude regions that are likely to be generally important for the structure or function of the wider protein family. We applied our method to two members of the serpin family of serine protease inhibitors. We first confirmed that our method successfully detected the known heparin binding site in antithrombin while excluding residues known to be generally important in the serpin family. We next applied our sequence analysis approach to neuroserpin and used our results to guide site‐directed polyalanine mutagenesis experiments. The majority of the mutant neuroserpin proteins were found to fold correctly and could still form inhibitory complexes with tissue plasminogen activator (tPA). Kinetic analysis of tPA inhibition, however, revealed altered inhibitory kinetics in several of the mutant proteins, with some mutants showing decreased association with tPA and others showing more rapid dissociation of the covalent complex. Altogether, these results confirm that our sequence analysis approach is a useful tool that can be used to guide mutagenesis experiments for the detection of specific functional sites in proteins. Proteins 2015; 83:135–152. © 2014 Wiley Periodicals, Inc.  相似文献   
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