利用LZF－1DNA指纹探针进行家系的父权鉴定

ＬＺＦ－１ＤＮＡ指纹探针经同位素γ－３２Ｐ－ＡＴＰ标记后，检测了４个家系１３个个体血样的ＤＮＡ指纹．结果表明，父母的遗传物质在子代中的传递符合孟德尔遗传规律，无误地确定了４个家系中的亲子血缘关系．ＬＺＦ－１ＤＮＡ指纹探针在亲权鉴定中的父权概率是０．９９９６４，达到了父权认定的目的     

Pollution and Genetic Structure of North American Populations of the Common Dandelion (Taraxacum Officinale)

Assessing the genetic structure of natural populations differentially impacted by anthropogenic contaminants can be a useful tool for evaluating the population genetic consequences of exposure to pollution. In this study, measures of genetic diversity at variable-number-tandem-repeat loci in six dandelion populations (3 urban and 3 rural) showed patterns that may have been influenced by exposure to environmental contaminants. Mean genetic similarity among individuals within a population was significantly and positively correlated with increasing levels of airborne particulate matter ( 10 m, PM₁₀) and soil concentrations of four metals (Cd, Fe, Ni and Pb). In addition, mean genetic similarity was always significantly higher at the urban sites compared to rural sites. There was a significant negative correlation between the number of genotypes at a site and increasing amounts of PM₁₀, concentrations of five soil metals (Cd, Cu, Fe, Ni and Pb), leaf tissue levels of Fe and a significant positive correlation between the extent of clonality at a site and levels of PM₁₀ and soil concentrations of five metals (Cd, Cu, Fe, Ni and Pb). Although, this study does not directly establish a causal link between the specific contaminants detected at the study sites and differences in genetic diversity, our data are consistent with the hypothesis that pollution-induced selection has contributed in some fashion to the lower genetic diversity found at the urban sites.     

Elevated 8-oxo-7,8-dihydro-2′-deoxyguanosine in genome of T24 bladder cancer cells induced by halobenzoquinones

Halobenzoquinones(HBQs) are an emerging class of halogenated disinfection byproducts(DBPs) in drinking water, which raised public concerns due to potential carcinogenic effects to human bladder. Our previous work demonstrated that HBQs and hydrogen peroxide(H_2O_2)together generated oxidative DNA damage via a metal-independent and intercalationenhanced oxidation mechanism in vitro. This study further investigated the efficiency of various HBQs to induce oxidative DNA damage in T24 bladder cancer cells. Compared with T24 cells without treatment(3.1 lesions per 10~6 d G), the level of 8-oxo-7,8-dihydro-2′-deoxyguanosine(8-oxod G) significantly increased by 1.4, 3.2, 8.8, and 9.2 times after treatment with tetrabromo-1,4-benzoquinone(TBBQ), terachloro-1,4-benzoquinone(TCBQ),2,6-dichloro-1,4-benzoquinone(2,6-DCBQ) and 2,5-dichloro-1,4-benzoquinone(2,5-DCBQ) for24 hr, respectively. Interestingly, we found that the oxidative potency of HBQs in T24 cells(2,5-DCBQ ≈ 2,6-DCBQ TCBQ TBBQ) is inconsistent with that of in vitro ds DNA oxidation(TCBQ TBBQ 2,5-DCBQ 2,6-DCBQ), suggesting HBQs induce oxidative lesions in cellular genomic DNA probably involved with a complex mechanism.     

DEP对蚯蚓抗氧化酶系的影响及DNA损伤

邻苯二甲酸二乙酯(DEP)是一种常见的塑料添加剂,并因塑料制品大量广泛使用而进入土壤环境,但其对土壤动物的毒性及其机制并未完全阐明.本文以赤子爱胜蚓(Eisenia foetida)为研究对象,使其暴露于不同含量DEP的模拟污染土壤,以蚯蚓体内的抗氧化酶活性、ROS含量、GST活性、MDA含量和DNA损伤程度为评估参数,研究含DEP污染土壤对蚯蚓的毒性作用并分析其机制.结果表明,在DEP胁迫作用下,蚯蚓体内的抗氧化酶和谷胱甘肽-S-转移酶(GST)活性、活性氧自由基(ROS)均发生变化并导致基因损伤产生.在28d的实验周期内0.1~50 mg·kg-1DEP的胁迫下,ROS含量水平呈现增加状态,存在"剂量-效应"关系,并且过量的ROS引起脂质过氧化反应造成机体内MDA含量增加.在ROS和MDA共同作用下,蚯蚓体腔内的DNA受到损伤并且损伤程度与DEP含量存在"剂量-效应"关系.从实验结果可以看出,DEP可以对蚯蚓机体和DNA造成一定程度的损伤,表现出较强的生态毒理效应.     

Workshop report on the extraction of foetal DNA from maternal plasma

Objective Cell free foetal DNA (cff DNA) extracted from maternal plasma is now recognized as a potential source for prenatal diagnosis but the methodology is currently not well standardized. To evaluate different manual and automated DNA extraction methods with a view to developing standards, an International Workshop was performed. Methods Three plasma pools from RhD-negative pregnant women, a DNA standard, real-time-PCR protocol, primers and probes for RHD were sent to 12 laboratories and also to one company (Qiagen, Hilden, Germany). In pre-tests, pool 3 showed a low cff DNA concentration, pool 1 showed a higher concentration and pool 2 an intermediate concentration. Results The QIAamp DSP Virus Kit, the High Pure PCR Template Preparation Kit, an in-house protocol using the QIAamp DNA Blood Mini Kit, the CST genomic DNA purification kit, the Magna Pure LC, the MDx, the M48, the EZ1 and an in-house protocol using magnetic beads for manual and automated extraction were the methods that were able to reliably detect foetal RHD. The best results were obtained with the QIAamp DSP Virus Kit. The QIAamp DNA Blood Mini Kit showed very comparable results in laboratories that followed the manufacturer's protocol and started with ≥ 500 µL plasma. One participant using the QIAamp DNA Blood Midi Kit failed to detect reliably RHD in pool 3. Conclusions This workshop initiated a standardization process for extraction of cff DNA in maternal plasma. The highest yield was obtained by the QIAamp DSP Virus Kit, a result that will be evaluated in more detail in future studies. Copyright © 2007 John Wiley & Sons, Ltd.