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The authors of “The anglerfish deception” respond to the criticism of their article.EMBO reports (2012) advanced online publication; doi: 10.1038/embor.2012.70EMBO reports (2012) 13 2, 100–105; doi: 10.1038/embor.2011.254Our respondents, eight current or former members of the EFSA GMO panel, focus on defending the EFSA''s environmental risk assessment (ERA) procedures. In our article for EMBO reports, we actually focused on the proposed EU GMO legislative reform, especially the European Commission (EC) proposal''s false political inflation of science, which denies the normative commitments inevitable in risk assessment (RA). Unfortunately the respondents do not address this problem. Indeed, by insisting that Member States enjoy freedom over risk management (RM) decisions despite the EFSA''s central control over RA, they entirely miss the relevant point. This is the unacknowledged policy—normative commitments being made before, and during, not only after, scientific ERA. They therefore only highlight, and extend, the problem we identified.The respondents complain that we misunderstood the distinction between RA and RM. We did not. We challenged it as misconceived and fundamentally misleading—as though only objective science defined RA, with normative choices cleanly confined to RM. Our point was that (i) the processes of scientific RA are inevitably shaped by normative commitments, which (ii) as a matter of institutional, policy and scientific integrity must be acknowledged and inclusively deliberated. They seem unaware that many authorities [1,2,3,4] have recognized such normative choices as prior matters, of RA policy, which should be established in a broadly deliberative manner “in advance of risk assessment to ensure that [RA] is systematic, complete, unbiased and transparent” [1]. This was neither recognized nor permitted in the proposed EC reform—a central point that our respondents fail to recognize.In dismissing our criticism that comparative safety assessment appears as a ‘first step'' in defining ERA, according to the new EFSA ERA guidelines, which we correctly referred to in our text but incorrectly referenced in the bibliography [5], our respondents again ignore this widely accepted ‘framing'' or ‘problem formulation'' point for science. The choice of comparator has normative implications as it immediately commits to a definition of what is normal and, implicitly, acceptable. Therefore the specific form and purpose of the comparison(s) is part of the validity question. Their claim that we are against comparison as a scientific step is incorrect—of course comparison is necessary. This simply acts as a shield behind which to avoid our and others'' [6] challenge to their self-appointed discretion to define—or worse, allow applicants to define—what counts in the comparative frame. Denying these realities and their difficult but inevitable implications, our respondents instead try to justify their own particular choices as ‘science''. First, they deny the first-step status of comparative safety assessment, despite its clear appearance in their own ERA Guidance Document [5]—in both the representational figure (p.11) and the text “the outcome of the comparative safety assessment allows the determination of those ‘identified'' characteristics that need to be assessed [...] and will further structure the ERA” (p.13). Second, despite their claims to the contrary, ‘comparative safety assessment'', effectively a resurrection of substantial equivalence, is a concept taken from consumer health RA, controversially applied to the more open-ended processes of ERA, and one that has in fact been long-discredited if used as a bottleneck or endpoint for rigorous RA processes [7,8,9,10]. The key point is that normative commitments are being embodied, yet not acknowledged, in RA science. This occurs through a range of similar unaccountable RA steps introduced into the ERA Guidance, such as judgement of ‘biological relevance'', ‘ecological relevance'', or ‘familiarity''. We cannot address these here, but our basic point is that such endless ‘methodological'' elaborations of the kind that our EFSA colleagues perform, only obscure the institutional changes needed to properly address the normative questions for policy-engaged science.Our respondents deny our claim concerning the singular form of science the EC is attempting to impose on GM policy and debate, by citing formal EFSA procedures for consultations with Member States and non-governmental organizations. However, they directly refute themselves by emphasizing that all Member State GM cultivation bans, permitted only on scientific grounds, have been deemed invalid by EFSA. They cannot have it both ways. We have addressed the importance of unacknowledged normativity in quality assessments of science for policy in Europe elsewhere [11]. However, it is the ‘one door, one key'' policy framework for science, deriving from the Single Market logic, which forces such singularity. While this might be legitimate policy, it is not scientific. It is political economy.Our respondents conclude by saying that the paramount concern of the EFSA GMO panel is the quality of its science. We share this concern. However, they avoid our main point that the EC-proposed legislative reform would only exacerbate their problem. Ignoring the normative dimensions of regulatory science and siphoning-off scientific debate and its normative issues to a select expert panel—which despite claiming independence faces an EU Ombudsman challenge [12] and European Parliament refusal to discharge their 2010 budget, because of continuing questions over conflicts of interests [13,14]—will not achieve quality science. What is required are effective institutional mechanisms and cultural norms that identify, and deliberatively address, otherwise unnoticed normative choices shaping risk science and its interpretive judgements. It is not the EFSA''s sole responsibility to achieve this, but it does need to recognize and press the point, against resistance, to develop better EU science and policy.  相似文献   

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The use of β-lactam antibiotics has led to the evolution and global spread of a variety of resistance mechanisms, including β-lactamases, a group of enzymes that degrade the β-lactam ring. The evolution of increased β-lactam resistance was studied by exposing independent lineages of Salmonella typhimurium to progressive increases in cephalosporin concentration. Each lineage carried a β-lactamase gene (blaTEM-1) that provided very low resistance. In most lineages, the initial response to selection was an amplification of the blaTEM-1 gene copy number. Amplification was followed in some lineages by mutations (envZ, cpxA, or nmpC) that reduced expression of the uptake functions, the OmpC, OmpD, and OmpF porins. The initial resistance provided by blaTEM-1 amplification allowed the population to expand sufficiently to realize rare secondary point mutations. Mathematical modeling showed that amplification often is likely to be the initial response because events that duplicate or further amplify a gene are much more frequent than point mutations. These models show the importance of the population size to appearance of later point mutations. Transient gene amplification is likely to be a common initial mechanism and an intermediate in stable adaptive improvement. If later point mutations (allowed by amplification) provide sufficient adaptive improvement, the amplification may be lost.THE extensive use of β-lactam antibiotics has led to the evolution and spread of many chromosomal-, plasmid-, and transposon-borne resistance mechanisms (Livermore 1995; Weldhagen 2004). Prominent among these mechanisms is a class of enzymes, β-lactamases, that hydrolyze the β-lactam ring (Ambler 1980; Poole 2004). TEM-1 β-lactamase, encoded by the blaTEM-1 gene, hydrolyzes both penicillins and early cephalosporins (Matagne et al. 1990). As bacteria developed resistance, stable extended-spectrum cephalosporins (ESCs) were introduced, leading to evolution of TEM sequence variants with improved ESC hydrolysis (Petrosino et al. 1998). Resistance to β-lactams can also result from mutations that reduce levels of outer membrane proteins involved in uptake, altered target proteins (penicillin-binding proteins) to reduce β-lactam binding, or increased expression of efflux pumps that export the antibiotics (Poole 2004; Martínez-Martínez 2008; Zapun et al. 2008).Resistance to β-lactam antibiotics is linearly correlated with the lactamase level over a large range (Nordström et al. 1972) and resistance to β-lactam antibiotics can be provided by increasing enzyme levels. An early illustration of this process is the finding that Escherichia coli can develop ampicillin resistance by amplifying its ampC gene (Edlund and Normark 1981). Similar amplification has been observed in both eubacteria and eukaryotes (Craven and Neidle 2007; Wong et al. 2007) in response to various selective pressures, including antibiotics (Andersson and Hughes 2009; Sandegren and Andersson 2009). In an unselected bacterial population, the frequency of cells with a duplication of any specific chromosomal region ranges between 10−2 and 10−5 depending on the region (Anderson and Roth 1981), whereas a point mutation in that gene is expected to be carried by perhaps 1 cell in 107–108 (Hudson et al. 2002). Thus, the rate of duplication formation is ∼10−5/cell/division and further increases ∼0.01/cell/division (Pettersson et al. 2008) while the base substitution rate is ∼10−10/cell/division/base pair (Hudson et al. 2002). Thus, it is apparent that variants with an increased level of any enzyme activity are more likely to owe the increase to a gene copy number change than to a point mutation. Furthermore, because of the high intrinsic instability of tandem amplifications, haploid segregants are expected to take over the population when the selection pressure is released (Pettersson et al. 2008).To examine the importance of gene amplification in bacterial adaptation to cephalosporins, several independent Salmonella typhimurium lineages carrying the blaTEM-1 gene were allowed to develop resistance to progressively increased concentrations of cephalothin (a first-generation cephalosporin) and cefaclor (a second-generation cephalosporin). As these lineages developed resistance to higher antibiotic levels, amplification of the blaTEM-1 gene was the primary and most common resistance mechanism, which in some cases was followed by acquisition of rare point mutations that provided stable resistance.  相似文献   

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In the preceding paper, using ECEPP, including the effects of water, and the chain build-up procedure, we computed the low energy structures for GnRH and found that there were no distinct low energy structures or structures with high statistical weights. To attempt to deduce possible structures of GnRH that may bind to the GnRH receptor, we computed the low energy structures for GnRH peptides that have l- and d-amino acids substituting for Gly 6. The l-amino acid-substituted peptides (l-Ala and l-Val) have very low or no affinity for the receptor and on activity (release of FSH and LH) while the d-Ala-, d-Leu-, d-Trp- and d-Phe-substituted peptides have significantly higher relative affinities and activities than those for native GnRH; the d-Val-substituted peptide has about one-third of the affinity and activity as native GnRH. Unlike native GnRH, our computations suggest that both sets of peptides form well-defined structures in water: the l-amino acid-substituted peptides are predominantly α-helical while the d-amino acid-substituted peptides adopted E*A A A E D*(C*) A E C A(C*) and minor variants of these structures. By eliminating structures that lay in common to the d-Ala and l-Val peptides and further eliminating structures that differed between the d-Ala and d-Leu peptides, we reduced the number of possible distinct binding conformations to 254. Searching for structures among these 254 conformations that had relative statistical weights that paralleled their relative affinities, we found two candidate structures: D*E A A E C*A E C A and D*G A A E D*A E C G*, both of which have conformations for residues 3–9 that are similar to the computed most probable structures for the d-amino acid-substituted GnRH peptides in water.  相似文献   

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Various tumor cells exhibit structural alterations in the sulfated modifications to glycosaminoglycans (GAGs). The altered expression of chondroitin sulfate (CS) and heparan sulfate (HS) on the surfaces of tumor cells is known to play a key role in malignant transformation and tumor metastasis. The receptor molecule for the CS chains containing E-disaccharide units (CS-E) expressed on Lewis lung carcinoma (LLC) cells was recently revealed to be Receptor for Advanced Glycation End-products (RAGE). RAGE is also involved in the development of various pathological conditions including aging, infection, pulmonary fibrosis, diabetes, and Alzheimer’s disease, by binding to a wide range of ligands. RAGE binds strongly not only to CS-E, but also to HS-expressing LLC cells. Recombinant RAGE bound CS-E and HS with high affinity. Furthermore, in a mouse model, the colonization of the lungs by LLC cells was inhibited by intravenously injected CS-E, an anti-CS-E antibody, or an anti-RAGE antibody. These findings demonstrated that RAGE is at least one of the critical receptors for CS and HS chains expressed on the tumor cell surface and is involved in experimental lung metastasis, and also that CS/HS and RAGE are potential molecular targets for the treatment of pulmonary metastasis. We, hence, reviewed these findings and also several chemically synthesized small GAGmimetics that exhibit potent anti-metastatic and/or anti-tumor activities.  相似文献   

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d-Serine is an endogenous coagonist for the N-methyl-d-aspartate receptor and is involved in excitatory neurotransmission in the brain. Mammalian pyridoxal 5′-phosphate-dependent serine racemase, which is localized in the mammalian brain, catalyzes the racemization of l-serine to yield d-serine and vice versa. The enzyme also catalyzes the dehydration of d- and l-serine. Both reactions are enhanced by Mg·ATP in vivo. We have determined the structures of the following three forms of the mammalian enzyme homolog from Schizosaccharomyces pombe: the wild-type enzyme, the wild-type enzyme in the complex with an ATP analog, and the modified enzyme in the complex with serine at 1.7, 1.9, and 2.2 Å resolution, respectively. On binding of the substrate, the small domain rotates toward the large domain to close the active site. The ATP binding site was identified at the domain and the subunit interface. Computer graphics models of the wild-type enzyme complexed with l-serine and d-serine provided an insight into the catalytic mechanisms of both reactions. Lys-57 and Ser-82 located on the protein and solvent sides, respectively, with respect to the cofactor plane, are acid-base catalysts that shuttle protons to the substrate. The modified enzyme, which has a unique “lysino-d-alanyl” residue at the active site, also exhibits catalytic activities. The crystal-soaking experiment showed that the substrate serine was actually trapped in the active site of the modified enzyme, suggesting that the lysino-d-alanyl residue acts as a catalytic base in the same manner as inherent Lys-57 of the wild-type enzyme.d-Serine, which is present at a high level in the mammalian brain, serves as an endogenous coagonist for the N-methyl-d-aspartate (NMDA)5 receptor selectively localized on the postsynaptic membrane of the excitatory synapse (15) and is involved in excitatory neurotransmission and higher brain functions such as learning and memory (3, 6, 7). Stimulation of the NMDA receptor requires the binding of d-serine as well as the agonist l-glutamate. The major enzyme for d-serine synthesis from l-serine in the brain is considered to be pyridoxal 5′-phosphate (PLP)-dependent serine racemase (SR) (810). d-Serine and SR are localized on protoplasmic astrocytes that have the α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor. Glutamate released from presynaptic neurons approaches and activates the α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor, which in turn induces SR to produce d-serine and is followed by d-serine release from astrocytes that act on the NMDA receptor. Recently, it was shown that not only glia but also neurons synthesize and release d-serine involved in signaling (11). SR also catalyzes α,β-elimination of water from d- or l-serine to form pyruvate and ammonia as well as the conversion of l-serine into d-serine and vice versa and is presumed to link d-serine synthesis and energy metabolism of astrocytes (12) and to control the d-serine level (13). Mg·ATP, which is fully bound to SR under physiological conditions, stimulates racemization and the α,β-elimination reaction catalyzed by SR (12, 14).SR was first discovered in pupae of the silkworm Bombyx mori (15), which was followed by purification of the enzyme from a rat brain and cloning of the mouse and human genes (8, 9). The primary structure of mammalian SR is distinct from those of racemases from prokaryotes but is similar to those of fold-type II PLP-dependent enzymes (1618). We have cloned and expressed the Schizosaccharomyces pombe gene homologous to human and mouse SRs, the sequence identities being 35.1 and 37.4%, respectively, in Escherichia coli. The protein product is a bifunctional enzyme that catalyzes racemization and the α,β-elimination reaction of D, l-serine as mammalian SR does. SR from S. pombe (spSR) comprises 322 residues (the N-terminal Met is removed in the purified enzyme) and one PLP per subunit, the subunit molecular weight being 34,917. The mammalian SR homolog, spSR, is an interesting target enzyme for the development of a novel therapeutic compound controlling the d-serine level because d-serine is the product of an SR-catalyzed reaction. In our recent report, the active site of spSR was shown to be modified with its natural substrate serine by mass spectroscopic and x-ray studies (19). Interestingly, the catalytic lysine, which originally forms a Schiff base with PLP, is converted to a lysino-d-alanyl residue through the reaction with the substrate, serine (Fig. 1). The modified enzyme exhibits racemase (54% of the wild-type enzyme) and α,β-elimination (68% of the wild-type enzyme) activities with the amino group of the d-alanyl moiety of the lysinoalanyl residue forming a Schiff base with PLP in place of the lysine (19). In addition, the mammalian SR seems to be possibly modified to have a lysinoalanyl residue at the active site, as observed in spSR (20).Open in a separate windowFIGURE 1.Covalent modification of the active site. The catalytic Lys-57 in spSRw is converted to lysino-d-alanyl residue. The α-amino group (indicated with “α”) of the d-alanyl moiety in the residue acts as a catalytic base in spSRm. The circled P is a phosphate group.Although the structure of modified spSR (spSRm) has been determined (19), the structure-function relationship of essential wild-type spSR (spSRw), the binding mode of activator Mg·ATP, the catalytic base to shuttle protons to the substrate d-serine, and the substrate recognition of the modified enzyme have not yet been uncovered. We now report the three-dimensional structures of unliganded spSRw in the open form, spSRw·AMP-PCP in the open form, and spSRm·serine in the closed form.  相似文献   

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Zhang JY 《EMBO reports》2011,12(4):302-306
How can grass-roots movements evolve into a national research strategy? The bottom-up emergence of synthetic biology in China could give some pointers.Given its potential to aid developments in renewable energy, biosensors, sustainable chemical industries, microbial drug factories and biomedical devices, synthetic biology has enormous implications for economic development. Many countries are therefore implementing strategies to promote progress in this field. Most notably, the USA is considered to be the leader in exploring the industrial potential of synthetic biology (Rodemeyer, 2009). Synthetic biology in Europe has benefited from several cross-border studies, such as the ‘New and Emerging Science and Technology'' programme (NEST, 2005) and the ‘Towards a European Strategy for Synthetic Biology'' project (TESSY; Gaisser et al, 2008). Yet, little is known in the West about Asia''s role in this ‘new industrial revolution'' (Kitney, 2009). In particular, China is investing heavily in scientific research for future developments, and is therefore likely to have an important role in the development of synthetic biology.Initial findings seem to indicate that the emergence of synthetic biology in China has been a bottom-up construction of a new scientific framework…In 2010, as part of a study of the international governance of synthetic biology, the author visited four leading research teams in three Chinese cities (Beijing, Tianjin and Hefei). The main aims of the visits were to understand perspectives in China on synthetic biology, to identify core themes among its scientific community, and to address questions such as ‘how did synthetic biology emerge in China?'', ‘what are the current funding conditions?'', ‘how is synthetic biology generally perceived?'' and ‘how is it regulated?''. Initial findings seem to indicate that the emergence of synthetic biology in China has been a bottom-up construction of a new scientific framework; one that is more dynamic and comprises more options than existing national or international research and development (R&D) strategies. Such findings might contribute to Western knowledge of Chinese R&D, but could also expose European and US policy-makers to alternative forms and patterns of research governance that have emerged from a grass-roots level.…the process of developing a framework is at least as important to research governance as the big question it might eventually addressA dominant narrative among the scientists interviewed is the prospect of a ‘big-question'' strategy to promote synthetic-biology research in China. This framework is at a consultation stage and key questions are still being discussed. Yet, fieldwork indicates that the process of developing a framework is at least as important to research governance as the big question it might eventually address. According to several interviewees, this approach aims to organize dispersed national R&D resources into one grand project that is essential to the technical development of the field, preferably focusing on an industry-related theme that is economically appealling to the Chinese public.Chinese scientists have a pragmatic vision for research; thinking of science in terms of its ‘instrumentality'' has long been regarded as characteristic of modern China (Schneider, 2003). However, for a country in which the scientific community is sometimes described as an “uncoordinated ‘bunch of loose ends''” (Cyranoski, 2001) “with limited synergies between them” (OECD, 2007), the envisaged big-question approach implies profound structural and organizational changes. Structurally, the approach proposes that the foundational (industry-related) research questions branch out into various streams of supporting research and more specific short-term research topics. Within such a framework, a variety of Chinese universities and research institutions can be recruited and coordinated at different levels towards solving the big question.It is important to note that although this big-question strategy is at a consultation stage and supervised by the Ministry of Science and Technology (MOST), the idea itself has emerged in a bottom-up manner. One academic who is involved in the ongoing ministerial consultation recounted that, “It [the big-question approach] was initially conversations among we scientists over the past couple of years. We saw this as an alternative way to keep up with international development and possibly lead to some scientific breakthrough. But we are happy to see that the Ministry is excited and wants to support such an idea as well.” As many technicalities remain to be addressed, there is no clear time-frame yet for when the project will be launched. Yet, this nationwide cooperation among scientists with an emerging commitment from MOST seems to be largely welcomed by researchers. Some interviewees described the excitement it generated among the Chinese scientific community as comparable with the establishment of “a new ‘moon-landing'' project”.Of greater significance than the time-frame is the development process that led to this proposition. On the one hand, the emergence of synthetic biology in China has a cosmopolitan feel: cross-border initiatives such as international student competitions, transnational funding opportunities and social debates in Western countries—for instance, about biosafety—all have an important role. On the other hand, the development of synthetic biology in China has some national particularities. Factors including geographical proximity, language, collegial familiarity and shared interests in economic development have all attracted Chinese scientists to the national strategy, to keep up with their international peers. Thus, to some extent, the development of synthetic biology in China is an advance not only in the material synthesis of the ‘cosmos''—the physical world—but also in the social synthesis of aligning national R&D resources and actors with the global scientific community.To comprehend how Chinese scientists have used national particularities and global research trends as mutually constructive influences, and to identify the implications of this for governance, this essay examines the emergence of synthetic biology in China from three perspectives: its initial activities, the evolution of funding opportunities, and the ongoing debates about research governance.China''s involvement in synthetic biology was largely promoted by the participation of students in the International Genetically Engineered Machine (iGEM) competition, an international contest for undergraduates initiated by the Massachusetts Institute of Technology (MIT) in the USA. Before the iGEM training workshop that was hosted by Tianjin University in the Spring of 2007, there were no research records and only two literature reviews on synthetic biology in Chinese scientific databases (Zhao & Wang, 2007). According to Chunting Zhang of Tianjin University—a leading figure in the promotion of synthetic biology in China—it was during these workshops that Chinese research institutions joined their efforts for the first time (Zhang, 2008). From the outset, the organization of the workshop had a national focus, while it engaged with international networks. Synthetic biologists, including Drew Endy from MIT and Christina Smolke from Stanford University, USA, were invited. Later that year, another training camp designed for iGEM tutors was organized in Tianjin and included delegates from Australia and Japan (Zhang, 2008).Through years of organizing iGEM-related conferences and workshops, Chinese universities have strengthened their presence at this international competition; in 2007, four teams from China participated. During the 2010 competition, 11 teams from nine universities in six provinces/municipalities took part. Meanwhile, recruiting, training and supervising iGEM teams has become an important institutional programme at an increasing number of universities.…training for iGEM has grown beyond winning the student awards and become a key component of exchanges between Chinese researchers and the international communityIt might be easy to interpret the enthusiasm for the iGEM as a passion for winning gold medals, as is conventionally the case with other international scientific competitions. This could be one motive for participating. Yet, training for iGEM has grown beyond winning the student awards and has become a key component of exchanges between Chinese researchers and the international community (Ding, 2010). Many of the Chinese scientists interviewed recounted the way in which their initial involvement in synthetic biology overlapped with their tutoring of iGEM teams. One associate professor at Tianjin University, who wrote the first undergraduate textbook on synthetic biology in China, half-jokingly said, “I mainly learnt [synthetic biology] through tutoring new iGEM teams every year.”Participation in such contests has not only helped to popularize synthetic biology in China, but has also influenced local research culture. One example of this is that the iGEM competition uses standard biological parts (BioBricks), and new BioBricks are submitted to an open registry for future sharing. A corresponding celebration of open-source can also be traced to within the Chinese synthetic-biology community. In contrast to the conventional perception that the Chinese scientific sector consists of a “very large number of ‘innovative islands''” (OECD, 2007; Zhang, 2010), communication between domestic teams is quite active. In addition to the formally organized national training camps and conferences, students themselves organize a nationwide, student-only workshop at which to informally test their ideas.More interestingly, when the author asked one team whether there are any plans to set up a ‘national bank'' for hosting designs from Chinese iGEM teams, in order to benefit domestic teams, both the tutor and team members thought this proposal a bit “strange”. The team leader responded, “But why? There is no need. With BioBricks, we can get any parts we want quite easily. Plus, it directly connects us with all the data produced by iGEM teams around the world, let alone in China. A national bank would just be a small-scale duplicate.”From the beginning, interest in the development of synthetic biology in China has been focused on collective efforts within and across national borders. In contrast to conventional critiques on the Chinese scientific community''s “inclination toward competition and secrecy, rather than openness” (Solo & Pressberg, 2007; OECD, 2007; Zhang, 2010), there seems to be a new outlook emerging from the participation of Chinese universities in the iGEM contest. Of course, that is not to say that the BioBricks model is without problems (Rai & Boyle, 2007), or to exclude inputs from other institutional channels. Yet, continuous grass-roots exchanges, such as the undergraduate-level competition, might be as instrumental as formal protocols in shaping research culture. The indifference of Chinese scientists to a ‘national bank'' seems to suggest that the distinction between the ‘national'' and ‘international'' scientific communities has become blurred, if not insignificant.However, frequent cross-institutional exchanges and the domestic organization of iGEM workshops seem to have nurtured the development of a national synthetic-biology community in China, in which grass-roots scientists are comfortable relying on institutions with a cosmopolitan character—such as the BioBricks Foundation—to facilitate local research. To some extent, one could argue that in the eyes of Chinese scientists, national and international resources are one accessible global pool. This grass-roots interest in incorporating local and global advantages is not limited to student training and education, but also exhibited in evolving funding and regulatory debates.In the development of research funding for synthetic biology, a similar bottom-up consolidation of national and global resources can also be observed. As noted earlier, synthetic-biology research in China is in its infancy. A popular view is that China has the potential to lead this field, as it has strong support from related disciplines. In terms of genome sequencing, DNA synthesis, genetic engineering, systems biology and bioinformatics, China is “almost at the same level as developed countries” (Pan, 2008), but synthetic-biology research has only been carried out “sporadically” (Pan, 2008; Huang, 2009). There are few nationally funded projects and there is no discernible industrial involvement (Yang, 2010). Most existing synthetic-biology research is led by universities or institutions that are affiliated with the Chinese Academy of Science (CAS). As one CAS academic commented, “there are many Chinese scientists who are keen on conducting synthetic-biology research. But no substantial research has been launched nor has long-term investment been committed.”The initial undertaking of academic research on synthetic biology in China has therefore benefited from transnational initiatives. The first synthetic-biology project in China, launched in October 2006, was part of the ‘Programmable Bacteria Catalyzing Research'' (PROBACTYS) project, funded by the Sixth Framework Programme of the European Union (Yang, 2010). A year later, another cross-border collaborative effort led to the establishment of the first synthetic-biology centre in China: the Edinburgh University–Tianjing University Joint Research Centre for Systems Biology and Synthetic Biology (Zhang, 2008).There is also a comparable commitment to national research coordination. A year after China''s first participation in iGEM, the 2008 Xiangshan conference focused on domestic progress. From 2007 to 2009, only five projects in China received national funding, all of which came from the National Natural Science Foundation of China (NSFC). This funding totalled ¥1,330,000 (approximately £133,000; www.nsfc.org), which is low in comparison to the £891,000 funding that was given in the UK for seven Networks in Synthetic Biology in 2007 alone (www.bbsrc.ac.uk).One of the primary challenges in obtaining funding identified by the interviewees is that, as an emerging science, synthetic biology is not yet appreciated by Chinese funding agencies. After the Xiangshan conference, the CAS invited scientists to a series of conferences in late 2009. According to the interviewees, one of the main outcomes was the founding of a ‘China Synthetic Biology Coordination Group''; an informal association of around 30 conference delegates from various research institutions. This group formulated a ‘regulatory suggestion'' that they submitted to MOST, which stated the necessity and implications of supporting synthetic-biology research. In addition, leading scientists such as Chunting Zhang and Huanming Yang—President of the Beijing Genomic Institute (BGI), who co-chaired the Beijing Institutes of Life Science (BILS) conferences—have been active in communicating with government institutions. The initial results of this can be seen in the MOST 2010 Application Guidelines for the National Basic Research Program, in which synthetic biology was included for the first time, among ‘key supporting areas'' (MOST, 2010). Meanwhile, in 2010, NSFC allocated ¥1,500,000 (approximately £150,000) to synthetic-biology research, which is more than the total funding the area had received in the past three years.The search for funding further demonstrates the dynamics between national and transnational resources. Chinese R&D initiatives have to deal with the fact that scientific venture-capital and non-governmental research charities are underdeveloped in China. In contrast to the EU or the USA, government institutions in China, such as the NSFC and MOST, are the main and sometimes only domestic sources of funding. Yet, transnational funding opportunities facilitate the development of synthetic biology by alleviating local structural and financial constraints, and further integrate the Chinese scientific community into international research.This is not a linear ‘going-global'' process; it is important for Chinese scientists to secure and promote national and regional support. In addition, this alignment of national funding schemes with global research progress is similar to the iGEM experience, as it is being initiated through informal bottom-up associations between scientists, rather than by top-down institutional channels.As more institutions have joined iGEM training camps and participated in related conferences, a shared interest among the Chinese scientific community in developing synthetic biology has become visible. In late 2009, at the conference that founded the informal ‘coordination group'', the proposition of integrating national expertise through a big-question approach emerged. According to one professor in Beijing—who was a key participant in the discussion at the time—this proposition of a nationwide synergy was not so much about ‘national pride'' or an aim to develop a ‘Chinese'' synthetic biology, it was about research practicality. She explained, “synthetic biology is at the convergence of many disciplines, computer modelling, nano-technology, bioengineering, genomic research etc. Individual researchers like me can only operate on part of the production chain. But I myself would like to see where my findings would fit in a bigger picture as well. It just makes sense for a country the size of China to set up some collective and coordinated framework so as to seek scientific breakthrough.”From the first participation in the iGEM contest to the later exploration of funding opportunities and collective research plans, scientists have been keen to invite and incorporate domestic and international resources, to keep up with global research. Yet, there are still regulatory challenges to be met.…with little social discontent and no imminent public threat, synthetic biology in China could be carried out in a ‘research-as-usual'' mannerThe reputation of “the ‘wild East'' of biology” (Dennis, 2002) is associated with China'' previous inattention to ethical concerns about the life sciences, especially in embryonic-stem-cell research. Similarly, synthetic biology creates few social concerns in China. Public debate is minimal and most media coverage has been positive. Synthetic biology is depicted as “a core in the fourth wave of scientific development” (Pan, 2008) or “another scientific revolution” (Huang, 2009). Whilst recognizing its possible risks, mainstream media believe that “more people would be attracted to doing good while making a profit than doing evil” (Fang & He, 2010). In addition, biosecurity and biosafety training in China are at an early stage, with few mandatory courses for students (Barr & Zhang, 2010). The four leading synthetic-biology teams I visited regarded the general biosafety regulations that apply to microbiology laboratories as sufficient for synthetic biology. In short, with little social discontent and no imminent public threat, synthetic biology in China could be carried out in a ‘research-as-usual'' manner.Yet, fieldwork suggests that, in contrast to this previous insensitivity to global ethical concerns, the synthetic-biology community in China has taken a more proactive approach to engaging with international debates. It is important to note that there are still no synthetic-biology-specific administrative guidelines or professional codes of conduct in China. However, Chinese stakeholders participate in building a ‘mutual inclusiveness'' between global and domestic discussions.One of the most recent examples of this is a national conference about the ethical and biosafety implications of synthetic biology, which was jointly hosted by the China Association for Science and Technology, the Chinese Society of Biotechnology and the Beijing Institutes of Life Science CAS, in Suzhou in June 2010. The discussion was open to the mainstream media. The debate was not simply a recapitulation of Western worries, such as playing god, potential dual-use or ecological containment. It also focused on the particular concerns of developing countries about how to avoid further widening the developmental gap with advanced countries (Liu, 2010).In addition to general discussions, there are also sustained transnational communications. For example, one of the first three projects funded by the NSFC was a three-year collaboration on biosafety and risk-assessment frameworks between the Institute of Botany at CAS and the Austrian Organization for International Dialogue and Conflict Management (IDC).Chinese scientists are also keen to increase their involvement in the formulation of international regulations. The CAS and the Chinese Academy of Engineering are engaged with their peer institutions in the UK and the USA to “design more robust frameworks for oversight, intellectual property and international cooperation” (Royal Society, 2009). It is too early to tell what influence China will achieve in this field. Yet, the changing image of the country from an unconcerned wild East to a partner in lively discussions signals a new dynamic in the global development of synthetic biology.Student contests, funding programmes, joint research centres and coordination groups are only a few of the means by which scientists can drive synthetic biology forward in ChinaFrom self-organized participation in iGEM to bottom-up funding and governance initiatives, two features are repeatedly exhibited in the emergence of synthetic biology in China: global resources and international perspectives complement national interests; and the national and cosmopolitan research strengths are mostly instigated at the grass-roots level. During the process of introducing, developing and reflecting on synthetic biology, many formal or informal, provisional or long-term alliances have been established from the bottom up. Student contests, funding programmes, joint research centres and coordination groups are only a few of the means by which scientists can drive synthetic biology forward in China.However, the inputs of different social actors has not led to disintegration of the field into an array of individualized pursuits, but has transformed it into collective synergies, or the big-question approach. Underlying the diverse efforts of Chinese scientists is a sense of ‘inclusiveness'', or the idea of bringing together previously detached research expertise. Thus, the big-question strategy cannot be interpreted as just another nationally organized agenda in response to global scientific advancements. Instead, it represents a more intricate development path corresponding to how contemporary research evolves on the ground.In comparison to the increasingly visible grass-roots efforts, the role of the Chinese government seems relatively small at this stageIn comparison to the increasingly visible grass-roots efforts, the role of the Chinese government seems relatively small at this stage. Government input—such as the potential stewardship of the MOST in directing a big-question approach or long-term funding—remain important; the scientists who were interviewed expend a great deal of effort to attract governmental participation. Yet, China'' experience highlights that the key to comprehending regional scientific capacity lies not so much in what the government can do, but rather in what is taking place in laboratories. It is important to remember that Chinese iGEM victories, collaborative synthetic-biology projects and ethical discussions all took place before the government became involved. Thus, to appreciate fully the dynamics of an emerging science, it might be necessary to focus on what is formulated from the bottom up.The experience of China in synthetic biology demonstrates the power of grass-roots, cross-border engagement to promote contemporary researchThe experience of China in synthetic biology demonstrates the power of grass-roots, cross-border engagement to promote contemporary research. More specifically, it is a result of the commitment of Chinese scientists to incorporating national and international resources, actors and social concerns. For practical reasons, the national organization of research, such as through the big-question approach, might still have an important role. However, synthetic biology might be not only a mosaic of national agendas, but also shaped by transnational activities and scientific resources. What Chinese scientists will collectively achieve remains to be seen. Yet, the emergence of synthetic biology in China might be indicative of a new paradigm for how research practices can be introduced, normalized and regulated.  相似文献   

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Geijsen N 《The EMBO journal》2012,31(10):2247-2248
Cell Stem Cell 10 4, 425–439 (2012); published online April062012The release of epigenetic boundaries during epigenetic reprogramming is poorly understood. In the recent issue of Cell Stem Cell Journal, Gillich and colleagues identify a unique role for Prdm14 in the acceleration of this process (Gillich et al, 2012).Pluripotent stem cells can be established from pre-implantation blastocyst embryos (embryonic stem cells, ESCs) as well as from the post-implantation epiblast stem cells (EpiSCs; Chenoweth et al, 2010). Murine ESCs and EpiSCs both express central pluripotency factors such as Oct4, Nanog and Sox2, yet the different developmental origins of these two cell types is clearly reflected in their molecular, epigenetic and functional properties. Murine ESCs appear to exist in a unique ‘naive'' state reminiscent of the pre-implantation epiblast. They are characterized by the expression of germ cell–related genes, a remarkably open chromatin structure with two active X chromosomes, and the functional ability to contribute to chimera formation upon blastocyst complementation (Nichols and Smith, 2011). In contrast, EpiSCs reflect the properties of the post-implantation epiblast, characterized by low-level expression of early determinants of somatic differentiation, a near-absence of germ cell gene expression, inactivation of one of the X chromosomes and negligible ability to support the development of chimeric mice. The conversion of primed to naive pluripotent state requires the release of epigenetic restrictions that are established in the post-implantation epiblast. It is thus a reprogramming process akin to the derivation of induced pluripotent stem cells (iPSCs) from somatic cells. The results on Prdm14 from Gillich and colleagues offer new insights into the underlying molecular mechanisms governing epigenetic reprogramming.  相似文献   

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Functional and numerical responses of the predators:Phytoseiulus persimilis Athias-Henriot,Metaseiulus occidentalis (Nesbitt), andAmblyseius chilenensis (Dosse) [Acarina, Phytoseiidae] were observed at prey (Tetranychus urticae Koch [Acarina, Tetranychidae]) densities up to 300 prey/6.45 cm2. Neither functional nor numerical response curves revealed any prey-predator interference effects, i.e.: the dome-shaped response curves (Holling, 1961), did not occur.  相似文献   

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