工能基因组学:T-DNA介导的基因诱捕和植物基因鉴定(英文)

拟南芥菜、水稻、蕃茄、土豆、玉米、小麦和大豆的全基因组测序为植物细胞和发育生 物学研究提供了许多有用的信息。基因组学的中心任务是利用这些信息去探索蛋白质的功能 和鉴定与发育有关的重要基因。尽管依赖于毁坏基因和产生可识别的突变表型的经典遗传学 方法仍然是极为成功的基因鉴定方法，借助于报告基因结构，随机插入植物基因组的T-DNA 介导的基因诱捕正发展成为植物细胞和发育生物学研究的极强有力的技术。本文描述了基因 诱捕、启动子诱捕和增强子诱捕在植物生物学中的应用，并且希望这些基因鉴定方法有助于 植物分子生物学家和生物技术工作者的研究。     

Changes in understory species diversity during theNothofagus pumilio forest management cycle

Human commercial activities must be compatible with sustainable management to achieve species conservation in the natural environment. After harvesting, diversity and abundance of understory species differ substantially from the pre-harvest situation. Have knowledge of the changes that logging produces in all components of the system allows us to develop management alternatives with reduced impacts. The objective of this work was to evaluate changes in density, biomass and diversity of understory species along a forest shelterwood cut system management cycle in aNothofagus pumilio forest. Six forest management situations (postharvesting stands and different phases of forest development) were sampled in a pureN. pumilio forest of Tierra del Fuego (Argentina) of middle-high site class (fromclass I toIII). Species number, density and biomass were modified substantially after a shelterwood cut. These were being greatest after cutting and falling substantially when the forest canopy closes during theinitial growth phase, returning to values similar to this virgin forest when themature phase was reached. The impact of the forest management on understory species diversity is analyzed and discussed. The silvicultural practices applied toN. pumilio forest in Tierra del Fuego permit the introduction of alien flora to the system, and produce great changes during the forest management cycle. To Celina Matteri, Itatí Ferraro, and Rosa Kofalt for their aid in taxonomical identification. To Juan Manuel Cellini, Ricardo Vukasovic and Gregorio Martínez Pastur for their participation in the field work; and to the sawmillLos Castores, Universidad Nacional de la Patagonia Austral, Centro Austral de Investigaciones Científicas and Instituto Nacional de Tecnología Agropecuaria for the institutional and financial support.     

Effects of no‐take area size and age of marine protected areas on fisheries yields: a meta‐analytical approach

Marine protected areas (MPAs) are often promoted as tools for biodiversity conservation as well as for fisheries management. Despite increasing evidence of their usefulness, questions remain regarding the optimal design of MPAs, in particular concerning their function as fisheries management tools, for which empirical studies are still lacking. Using 28 data sets from seven MPAs in Southern Europe, we developed a meta‐analytical approach to investigate the effects of protection on adjacent fisheries and asking how these effects are influenced by MPA size and age. Southern European MPAs showed clear effects on the surrounding fisheries, on the ‘catch per unit effort’ (CPUE) of target species, but especially on the CPUE of the marketable catch. These effects depended on the time of protection and on the size of the no‐take area. CPUE of both target species and the marketable catch increased gradually by 2–4% per year over a long time period (at least 30 years). The influence of the size of the no‐take area appeared to be more complex. The catch rates of the entire fishery in and around the MPA were higher when the no‐take areas were smaller. Conversely, catch rates of selected fisheries that were expected to benefit most from protection increased when the no‐take area was larger. Our results emphasize the importance of MPA size on its export functions and suggest that an adequate, often extended, time frame be used for the management and the evaluation of effectiveness of MPAs.     

Development of biomarkers inAporrectodea caliginosa andLumbricus rubellus for detecting exposure to benzo[a]pyrene

Objectives and Methods. The sensitivity of two biomarkers, the neutral red retention assay (NRRA) and cytochrome P450 were evaluated in the earthwormAporrectodea caliginosa for their potential to detect exposure to benzo[a]pyrene (BaP). Cytochrome P450 was also evaluated in the earthwormLumbricus rubellus, and measured using the substrate ethoxycoumarin. Optimal assay conditions (pH, and temperature) were determined, followed by exposure of earthworms to 20 mg/kg BaP (a typical concentration at contaminated sites in New Zealand). Ethoxycoumarin-O-dealkylase (ECOD) activity was measured after 7, 14, and 21 days exposure. The NRRA was evaluated in earthworms exposed to 0.2, 20, and 100 mg BaP/kg, and biomarker responses were compared with effects on body weight. Results and Discussion Benzo[a]pyrene failed to induce ECOD activity in either earthworm species, and therefore it is not useful as a biomarker of BaP exposure and was not evaluated further. In all cases, the NRRA was significantly affected in the absence of any effects on earthworm body weight, indicating that this assay can detect exposure to BaP at a range of concentrations comparable to those found at contaminated sites. The NRRA should be linked to reproductive endpoints, then it can be used as an early warning indicator of adverse effects. Establishing biomarker stability under environmental conditions is an important step in biomarker development. Therefore, the effects of soil type (sandy soil, silt loam, and a clay soil), moisture content (15–30%), and temperature (5–20°) on the NRRA were determined. In all cases, there was no effect on the NRRA, indicating that this assay is very stable under varying environmental conditions. Conclusion and Outlook In conclusion, cytochrome P450 activity does not appear to be a useful indicator of PAH exposure in eitherA. caliginosa or L.rubellus, and due to the inherently low activity, it is not suitable as a routine biomarker for detecting environmental contamination by these compounds. In contrast, the NRRA in the earthworm A.caliginosa is a promising indicator of PAH exposure at the concentrations likely to be found in contaminated sites in New Zealand, and therefore has potential for evaluating these contaminated sites. If the NRRA can be linked to ecologically important life-cycle endpoints, such as reproduction, then it could be used as an early warning indicator of adverse effects at contaminated sites, i.e., by measuring biomarker responses in earthworms from a ‘contaminated area’ and comparing these with earthworms from a matched control area.     

Changes in glucosinolate concentrations, myrosinase activity, and production of metabolites of glucosinolates in cabbage (Brassica oleracea Var. capitata) cooked for different durations

In cabbage, glucosinolates such as sinigrin are hydrolyzed by plant myrosinase to allyl isothiocyanate (AITC), allyl cyanide, and, in the presence of an epithiospecifier protein, 1-cyano-2,3-epithiopropane (CEP). Isothiocyanates have been implicated in the cancer-protective effects of Brassica vegetables. The effect of processing on the hydrolysis of glucosinolates was investigated in cabbage. Cabbage was steamed or microwaved for six time durations over 7 min. Glucosinolate concentrations were slightly reduced after microwave cooking (P < 0.001) but were not influenced after steaming (P < 0.05). Myrosinase activity was effectively lost after 2 min of microwave cooking and after 7 min of steaming. Hydrolysis of residual glucosinolates following cooking yielded predominantly CEP at short cooking durations and AITC at longer durations until myrosinase activity was lost. Lightly cooked cabbage produced the highest yield of AITC on hydrolysis in vitro, suggesting that cooking Brassica vegetables for a relatively short duration may be desirable from a health perspective.     

Efficiency of Mesocosm-Scale Constructed Wetland Systems for Treatment of Sanitary Wastewater Under Tropical Conditions

Subsurface-flow constructed wetlands technology (SSFW) has been used successfully for treating sanitary wastewater throughout North America and Europe. However, treatment wetland technologies have not been used extensively in the tropics. To advance tropical studies, a pilot-scale SSFW was constructed on the campus of the University of the Atlantic in Barranquilla, Colombia. The systems performance was monitored from January to July of 2009. The treatment system consisted of a 760-L septic tank followed by three mesocsom-scale subsurface-flow constructed wetlands in parallel arrangement. Clarified wastewater was batch loaded to each unit at a rate of 53 L/m²/day to affect a hydraulic retention time of approximately 3 days. One of the treatment units served as a non-planted control (gravel only), while the other two treatment units were planted with either Eriochloa aristata or Eleocharis mutata. The objective of this study was to evaluate the comparative efficacy of the treatment units (planted vs. unplanted), with respect to their abilities to augment treatment of septic tank effluent (sanitary wastewater). Monitored parameters included plant biomass, oxidation?Creduction potential, chemical oxygen demand (COD), temperature, dissolved oxygen, pH, ammonia?Cnitrogen (NH ₄ ⁺ ?CN) nitrate?C and nitrite?Cnitrogen (NO₃?CN, NO₂?CN), phosphates (PO ₄ ^? ), and coliform bacteria. Total biomass (dry matter) was 2.84 and 0.87 Kg/m² for E. aristata and E. mutata, respectively. Redox potential in the plant rizospheres averaged ?172 mV (±164.1) in E. aristata, 29 mV (±251.1) in E. mutata, and 32 mV (±210.5) in the unplanted control. COD removal was superior in planted vs. non-planted systems (>75% vs. 47%). Ammonia and total phosphorus removal averaged 69% and 85%, respectively, in planted systems versus 31% and 59% in the unplanted system. Removal of total and fecal coliforms averaged 96%. Results of this pilot study revealed that SSFW technology in the tropics can provide significant removal of organic matter, nutrients, and bacteria from clarified sanitary wastewater.     

Validation of a multiplex PCR assay to detect Babesia spp. and Anaplasma marginale in cattle in Uruguay in the absence of a gold standard test

Detection of bovine Babesia spp. and Anaplasma marginale is based on the reading of Giemsa-stained blood or organ smears, which can have low sensitivity. Our aim was to improve the detection of bovine Babesia spp. and A. marginale by validating a multiplex PCR (mPCR). We used 466 samples of blood and/or organs of animals with signs and presumptive autopsy findings of babesiosis or anaplasmosis. The primers in our mPCR amplified the rap-1a gene region of Babesia bovis and B. bigemina, and the msp-5 region of A. marginale. We used a Bayesian model with a non-informative priori distribution for the prevalence estimate and informative priori distribution for estimation of sensitivity and specificity. The sensitivity and specificity for smear detection of Babesia spp. were 68.6% and 99.1%, and for A. marginale 85.6% and 98.8%, respectively. Sensitivity and specificity for mPCR detection for Babesia spp. were 94.2% and 97.1%, and for A. marginale 95.2% and 92.7%, respectively. Our mPCR had good accuracy in detecting Babesia spp. and A. marginale, and would be a reliable test for veterinarians to choose the correct treatment for each agent.