基于代谢组学技术的金刚烷胺胁迫刺参的毒性作用机制研究

本研究基于非靶向代谢组学方法,分析了暴露于100 μg·L^-1金刚烷胺下96 h的刺参代谢物组成及含量变化,以探究金刚烷胺对刺参肠道组织毒性及其相关分子机制。代谢组学结果表明,与对照组相比,金刚烷胺胁迫下,刺参肠道代谢物发生改变,共有115种差异表达代谢物,其主要功能分为二肽、类固醇、嘌呤和嘧啶。差异代谢物功能通路的富集结果表明,氨基酸代谢、脂质代谢、信号转导、核苷酸代谢和内分泌系统等生物过程受到显著影响。根据筛选出的差异代谢物的生理功能及其涉及的代谢通路分析,发现刺参信号传导和能量代谢功能受到干扰,可能由于腺苷和单磷酸腺苷(AMP)含量下降;睾酮和牛磺鹅去氧胆酸(TCDCA)含量下降可能对刺参的性别分化和胆固醇代谢产生影响;甘氨酸和脯氨酸含量上升可能是刺参胶原蛋白的降解造成的。本研究探究了金刚烷胺对刺参肠道组织毒性作用的分子机制及刺参的响应调控机制,为后期深入研究毒性机制提供理论依据。     

Cave molly females (Poecilia mexicana, Poeciliidae, Teleostei) like well-fed males

We examined the preference of Atlantic molly females (Poecilia mexicana) to associate with a well-fed or a starved male in simultaneous choice tests. Females from three different populations were tested in three treatments: (1) the females could choose on the basis of multiple cues from the males (visual plus non-visual); (2) only non-visual cues could be perceived in darkness, (3) only visual cues were presented. The three tested populations differ clearly in their ecology: one population occurs in a typical river habitat, the second one in a milky sulfur creek outside a cave, and the third population occurs in a cave habitat (cave molly). In the river-dwelling population, females never showed a preference. In the population from the sulfur creek, females preferred to associate with the well-nourished male when visual cues from the males were available. Only cave molly females exhibited a strong preference for well-nourished males in all treatments. A morphological comparison demonstrated that wild-caught males from river habitats are typically in a good nutritional state. In the sulfur creek, males showed signs of starvation. Cave molly males were in an even worse nutritional state. In the cave population, saturated males probably indicate high fitness, thereby driving the evolution of the preference for good male nutritional state.Communicated by K. Lindström     

Should all disaster risks be reduced? A perspective from the systems concept of the edge of chaos

The field of disaster risk reduction (DRR) has risen to prominence since the declaration of the International Decade of Disaster Risk Reduction between 1990 and 2000. This decade provided the impetus for a change from the predominant paradigm of disaster response to that of disaster risk reduction as a means of addressing the underlying drivers that lead to disasters. In an effort to promote risk reduction, the UNISDR (the principal agency for disaster risk reduction within the UN structure) formulated policies and strategies to provide both conceptual and practical guidance as to how risk should be reduced. However noble the efforts, this paper contends that the current approach to and understanding of risk within the international community might not be cognisant of complex adaptive systems (CAS) concepts such as the edge of chaos. Specifically, this concept argues that risk (or chaos) within a system is actually a fundamental requirement to the functioning of all resilient socio-ecological systems. Therefore, the reduction of risk without an understanding of the role of that risk within the larger socio-ecological system might actually end up reducing the system’s overall level of disaster resilience. This paper aims to explore the concept of edge of chaos through a literature review of key theoretical works on the topic, followed by a discussion on its implications for the predominant paradigm of risk reduction within disaster risk management policy and practice.     

Rhodobacter sp. NP25b菌株缺氧降解壬基酚聚氧乙烯醚的研究

从城市污水处理厂活性污泥中分离得到一株能够在缺氧条件下以壬基酚聚氧乙烯醚(NPEOs)为惟一碳源和能源生长的菌株NP25b.经生理生化鉴定和16S rRNA基因序列分析,该菌株属于红细菌属(Rhodobacter sp.),对该菌株降解NPEOs的特性进行了研究.结果表明,在缺氧条件下,菌株NP25b在7 d内对初始底物浓度为400 mg/L NPEOs的降解率可达84%.利用液相色谱-质谱(LC-MS)和气相色谱-质谱(GC-MS)对NPEOs降解中间产物进行了分析,结果表明,主要降解产物为短链NPEOs和壬基酚聚氧乙烯醚乙酸(NPECs),其中包括具有较强内分泌干扰效应的NP1EO.该菌株能够代谢含有疏水基团的聚氧乙烯醚类表面活性剂,例如辛基酚聚氧乙烯醚和脂肪醇聚氧乙烯醚.推测菌株NP25b降解NPEOs是通过乙氧基(EO)链末端氧化后逐步切割完成的.     

双酚类化合物的生物代谢机理研究进展

以双酚A(bisphenol A,简称BPA)及其替代物为代表的双酚类化合物(bisphenols,简称BPs)在各种环境介质、食品、消费品以及人类和动物体中被广泛检出,表明BPs存在全球性大规模污染趋势.除了BPs自身毒性外,其在生物体内的转化代谢产物可能具有比母体化合物更复杂的内分泌干扰效应和毒性效应,对于人体生命健康的影响不容小觑.本文就BPs生物代谢的实验和理论计算研究方法及其取得的研究成果等方面进行回顾总结,在分析现有研究存在的问题和不足上对未来的研究重点提出了展望.     

丙酮酸生物代谢途径及代谢控制的研究进展

丙酮酸作为生物代谢途径的重要中间产物,在代谢过程中起着枢纽作用,其又作为一种可再生资源,是众多大宗化学品的前驱体. 与传统化学方法相比,生物技术法生产丙酮酸具有环境友好、过程高效、可持续发展等优势. 本文总结了丙酮酸生物代谢的主要途径及原理;从生物合成、分解、关键酶调控方面总结了生物自身代谢丙酮酸的调控机制;综述了通过基因敲除、选育营养缺陷型菌株、设计及应用丙酮酸脱氢酶系抑制剂等手段阻断丙酮酸代谢途径等系列工作;介绍以丙酮酸脱氢酶系等关键酶为切入点进行代谢过程控制的方法可行性;构建了以丙酮酸或以其为纽带进行废物资源化回收利用的愿景. 以期为生物技术法高效生产丙酮酸提供理论借鉴,推动以丙酮酸或以其为纽带进行废物资源化的研究进程.     

Ontogenetic habitat shift and risk of cannibalism in the common chameleon (Chamaeleo chamaeleon)

Ontogenetic habitat shifts have been documented in numerous fish and amphibians and in some reptiles. Intraspecific competition together with differential predation, prey size, social interactions, size-related thermal requirements, and morphological constraints on movement are often implicated in this ontogenetic habitat separation. In the current study, we combined field observation with experiments in seminatural arenas to test various hypotheses regarding the ontogenetic habitat shift that we have documented in the common chameleon. Juveniles (mean, 1 g) occupied low grasses and the adults (mean, 35 g) were found on bushes and trees. Overlap in habitat use between these two age classes was minimal. Our field experiments showed that juveniles actively avoid the presence of adults by concealment or flight. Adults readily attacked and consumed juveniles, regardless of their own mass. These results suggest that the risk of cannibalism towards juveniles is an important selective force behind the ontogenetic habitat shift observed in the common chameleon and may be important in other species too.