利用唐鱼雌激素受体构建环境雌激素重组酵母测评系统的研究

利用唐鱼雌激素受体基因片段构建重组酵母,用以筛选环境雌激素类化学物质.实验先将唐鱼雌激素受体terα基因片段插入载体pGADT7中构建表达质粒p GADT7/TERα,同时将雌激素效应元件(ere)片段插入pMP206载体中构建报告质粒pMP206/ERE-Lac Z;然后把表达质粒和报告质粒共转化到酵母AH109中,经筛选成功构建了由唐鱼雌激素受体调控的表达lac Z基因的重组酵母AHpTERα/ERE.结果表明,所构建的重组酵母AHpTERα/ERE在不同浓度17β-雌二醇(E2)的诱导下,β-半乳糖苷酶的活性呈现出明显的剂量-效应关系,其EC50为(0.521±0.700)nmol·L-1.与DMSO对照组相比,重组酵母在17β-雌二醇诱导下有明显的β-半乳糖苷酶活性增强的现象.在不同浓度17α-乙炔基雌二醇(EE2)、壬基酚(NP)及其混合物、双酚A(BPA)、17β-雌二醇(E2)(阳性对照)的诱导下,重组酵母均呈现出剂量-效应关系,且灵敏度大小为E2EE2NPBPA.结果表明,本研究成功构建了重组基因酵母测评系统,初步判定该重组酵母可应用于环境雌激素的筛选.     

现代受体模式评述

传统的数学受体模式可概括地分为两大类,即化学质量平衡法(CMB)和多元技术(MVT),CMB由于要求已知所求源的成分谱。从而在应用中受到限制。MVT以因子模式为中心,由于因子模式的本征向量解法求解不唯一或称误差太大,使得MVT给人一种人造数据的印象。近年来,元素示踪体系将受体模式的应用范围从城市尺度扩展到区域尺度,由于该体系经验性太强,未能得到广泛的应用。本文针对现代受体模式中存在的一些关键性问题作了系统的评述。      

安徽涡河流域水化学与同位素特征及水体转化关系

以安徽涡河流域为研究区域,通过采集涡河地表水、浅层地下水和中深层地下水样品,运用Gibbs图、离子比例和MixSIAR模型等方法对各类水体的水化学参数和氢氧同位素进行分析,揭示并量化了各类水体之间的转化关系.结果表明,研究区地表水和地下水主要呈现中性至弱碱性,地表水的水化学类型以Cl·SO₄ ·HCO₃ -Na和Cl·SO₄ -Na型为主,浅层地下水以HCO₃ -Ca·Mg和HCO₃ -Mg·Na型为主,中深层地下水主要为Cl·HCO₃ -Na型.各类水体的水化学特征受到岩石风化、蒸发浓缩及正向阳离子交换等多重因素共同影响.地表水和地下水的δ¹⁸O和δ²H分布特征表明大气降水是该区域水体的主要补给来源,且地下水δ¹⁸O和δ²H值与K⁺、Na⁺、Cl^-、SO₄ ^2-和NO 3^-浓度存在显著相关性.根据MixSIAR模型分析结果,地表水接受大气降水和浅层地下水的贡献率分别为46.5 %和53.5 %;浅层地下水的补给来源分别为大气降水（57.4 %）和地表水（42.6 %）;中深层地下水的补给主要来自上游地下水的侧向径流补给.     

Mortality and other determinants of bird divorce rate

Pair bonds can end in two different ways: either death of the partner or divorce, where the frequency of divorce varies enormously among bird species, from 0% to 100%. To better understand this variation, we created and analyzed the largest dataset so far, consisting of 158 species and 20 variables that quantify the species’ body size, life history, diet, and other characteristics. Our results suggest that species with a high divorce rate have a high mortality rate, tend to be ornamented and sexually dichromatic, live colonially, and form part-time rather than continuous partnerships. Traits quantifying body size or life history are often nonlinearly related with divorce rate. These nonlinearities might (partly) be caused by nonlinear relationships of the same traits with mortality rate which is, in turn, linearly related with divorce rate. In contrast to what has been found previously, mortality rate appears as a key factor for divorce rate in our study. This makes sense, as the likelihood that a partner survives from one year to the next decreases with increasing mortality rate, diminishing the likely success of a partner that attempts to locate its previous partner. We also found taxonomic differences in divorce rate. Specifically, Anseriformes have an exceptionally low divorce rate, which, however, can be explained by the generally important determinants of divorce rate: They also have a lower mortality rate, lower degree of ornamentation and coloniality, and more continuous partnerships than members of other orders. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

BDE-28对斑马鱼核受体介导的内分泌干扰效应研究

2,4,4’-三溴联苯醚(BDE-28)在环境中普遍存在,且在长江流域多种水生生物中检出。目前,国内外对高溴代PBDEs(如BDE-47、BDE-99等)的水生脊椎动物内分泌干扰效应报道较多,而BDE-28的有关研究则相对较少。将斑马鱼胚胎暴露于2、20和200μg·L~(-1)的BDE-28后,借助q-RT-PCR方法对幼鱼8个重要受体包括雄激素受体(AR)、甲状腺激素受体(TR)、芳香烃受体(AhR)、雌激素受体(ER)、糖皮质激素受体(GR)、孕烷X受体(PXR)、盐皮质激素受体(MR)和过氧化物酶体增殖物激活受体(PPAR)相关基因的转录水平进行了研究。结果表明,BDE-28暴露可导致AR、TR和Ah R的基因下调,其中核心受体AR和TR在低中高3种浓度下的下调倍数分别为3.03、2.64、10.10和2.21、2.18、2.31,芳香烃受体基因2(ahr2)在暴露于2和20μg·L~(-1)的BDE-28后,下调倍数分别为12.65和9.23,而雌激素受体(er1)基因在低中高浓度显著上调,上调倍数分别为12.29、12.67和15.87,雌激素受体(er2a)基因在2和20μg·L~(-1)BDE-28下的上调倍数分别为10.83和17.19。进一步采用分子对接和分子动力学模拟的方法研究BDE-28与AR、TR、Ah R和ER之间的相互作用。结果显示,BDE-28与这些受体通过疏水和氢键等相互作用稳定结合,动力学模拟后骨架原子的均方根偏差(RMSD)在5 ns后较稳定。由此可知,BDE-28通过AR、TR、Ah R和ER受体介导产生内分泌干扰效应。     

镉、汞、锌3种重金属的雌激素样作用（Estrogenic Activity of Cadmium, Mercury, and Zinc）

为探讨镉、汞、锌3种重金属的雌激素样作用,采用双杂交酵母法测定了醋酸镉、氯化汞、醋酸锌单独作用时对重组基因酵母β-半乳糖苷酶诱导活性的EC50值.实验结果表明,醋酸镉浓度为1.0×10-5mol·L-(1实验浓度范围10-7~10-2mol·L-1),氯化汞浓度为5.0×10-7mol·L-(1实验浓度范围10-9~10-5mol·L-1),醋酸锌浓度为1.0×10-4mol·L-(1实验浓度范围10-9~10-2mol·L-1)时对酵母β-半乳糖苷酶诱导活性最大,分别达到1.3、0.95和1.1U.不能求出镉、汞、锌单独作用时对β-半乳糖苷酶诱导活性的EC50值.一味计算EC50值不仅难以评价重金属的雌激素活性,而且限制重组受体基因酵母法的普遍运用.一些重金属通过MCF-7细胞法(E-screen)呈阳性,通过重组hERα酵母法YES检测呈阴性,有可能是重金属通过与ERβ作用而产生效应.若构建出含ERβ基因的双杂交酵母菌株,与现有的方法互补将能完善环境雌激素的体外测评系统.     

Evaluation of the fish short term reproduction assay for detecting endocrine disrupters

In a fish testing strategy, positive results of the fish short term reproduction assay (FSTR), often trigger a definitive test like the fish sexual development test (FSDT) or the fish full life cycle test (FFLC), entailing ethical and economic problems. This study analysed 137 studies encompassing 35 chemicals with different modes of actions (MOAs). Variability is quantified for MOA endpoints vitellogenin (VTG) and secondary sex characteristics (SSCs) as well as for apical endpoints. Two MOA endpoints could indicate estrogenic, anti-estrogenic, androgenic, anti-androgenic and steroidogenesis activities. Great variability, however, has been observed for chemicals with anti-androgenic and steroidogenesis activities, suggesting that TG229/230 may not be sensitive enough to detect these types of chemicals and may produce false negatives. Changes in apical endpoints like fecundity are not limited to endocrine disrupting chemicals (EDCs). Non-EDCs could induce the similar effects on these apical endpoints. If elucidating MOA is needed, targeted in vitro MOA tests are suggested. Positive in vitro MOA results trigger a definitive test, which could be used for confirmation of the MOA in vivo and for deriving a no observed effect concentration (NOEC). Based on positive MOA results of TG229, a definitive test such as the FSDT or the FFLC is still needed, because the current TG229 has limitation on the derivation of a NOEC. An extended TG229 with more power to detect reproduction effects, as recently proposed in the OECD test guideline program, would improve the possibility to derive a NOEC and increase its usefulness in risk assessment.     

The policy consequences of defining rewilding

More than 30 years after it was first proposed as a biodiversity conservation strategy, rewilding remains a controversial concept. There is currently little agreement about what the goals of rewilding are, and how these are best achieved, limiting the utility of rewilding in mainstream conservation. Achieving consensus about rewilding requires agreeing about what “wild” means, but many different definitions exist, reflecting the diversity of values in conservation. There are three key debates that must be addressed to find a consensual definition of “wild”: (1) to which extent can people and “wild” nature co-exist?; (2) how much space does “wild” nature need? and (3) what kinds of “wild” nature do we value? Depending on the kinds of “wild” nature rewilding aims to create, rewilding policy will be faced with managing different opportunities and risks for biodiversity and people.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01560-8.     

Brief exposure to copper induces apoptosis and alters mediators of olfactory signal transduction in coho salmon

Pacific salmon are particularly susceptible to copper (Cu)-induced olfactory injuries that can ultimately inhibit neurobehaviors critical to survival. However, the molecular mechanisms underlying Cu-mediated olfactory impairment remain poorly understood. In the present study, we conducted a short-term Cu exposure at levels relevant to urban runoff (5, 25 and 50 ppb) , and investigated the roles of impaired olfactory signal transduction and induced apoptosis as underlying mechanisms of olfactory injury. Increased cell death in the olfactory epithelium was evident in coho receiving 4 h exposures to 25 and 50 ppb Cu. Expression of olfactory marker protein (omp), a marker of mature olfactory sensory neurons, also decreased at 50 ppb Cu. Immunohistochemical analysis of coho olfactory epithelium demonstrated a loss of type 3 adenylate cyclase (ACIII) in the apical olfactory epithelium cilia at all levels of Cu exposure, suggesting an inhibitory effect of Cu in olfactory signaling. Accompanying the loss of ACIII in Cu-exposed coho were reduced intracellular cyclic guanosine monophosphate (cGMP) levels in the olfactory rosettes. Collectively, these results support a linkage among the initial steps of olfactory signaling in Cu-induced salmon olfactory injury, and suggesting that monitoring olfactory cGMP levels may aid in the assessment of salmon olfactory injury.     

Assays of dioxins and dioxin-like compounds in actually contaminated soils using transgenic tobacco plants carrying a recombinant mouse aryl hydrocarbon receptor-mediated β-glucuronidase reporter gene expression system

The transgenic tobacco plant XD4V-26 carrying the recombinant mouse aryl hydrocarbon receptor XD4V-mediated β-glucuronidase (GUS) reporter gene expression system was used for assay of dioxins and dioxin-like compounds consisting of polychlorinated dibenzeno-p-dioxins, polychlorinated dibenzofurans, and coplanar polychlorinated biphenyls (Co-PCBs) in actually contaminated soils. The transgenic tobacco plant XD4V-26 showed a significant dose-dependent induced GUS activity when cultured on MS medium containing PCB126 [toxic equivalency factor (TEF) = 0.1]. In contrast, PCB169 and PCB180, which have 0.03 of TEF and unassigned TEF values, respectively, did not significantly induce GUS activity under the same conditions as with PCB126. When the tobacco plants were cultivated for up to 5 weeks on actually contaminated soils with dioxins and dioxin-like compounds collected from the periphery of an incinerator used for disposal of residential and industrial wastes, GUS activity in the leaves was dose-dependently increased. The plants clearly detected 360 pg-TEQ g^?1 of dioxins and dioxin-like compounds in this assay. There was a positive correlation between GUS activity and TEQ value of dioxins and dioxin-like compounds in the plants. This assay does not require any extraction and purification processes for the actually contaminated soil samples.