《汞暴露导致秀丽线虫后代中出现可传递的表型和行为缺陷》由会员分享，可在线阅读，更多相关《汞暴露导致秀丽线虫后代中出现可传递的表型和行为缺陷（30页珍藏版）》请在金锄头文库上搜索。
1、1汞暴露导致秀丽线虫后代中出现可传递的表型和行为缺陷【摘要】 目的：研究汞暴露秀丽线虫表型和行为缺陷在后代中的可传递特性。方法：寿命、身体尺寸、身体弯曲频率、头部摆动频率和化学趋向可塑性用于汞急性毒害评价,并进一步分析表型和行为缺陷从汞暴露的当代到后代的可传递特性。结果：汞暴露能够引起包括寿命、身体尺寸、身体弯曲频率、头部摆动频率和化学趋向可塑性等参数在内的多重生物学缺陷,且其毒害与所暴露汞浓度之间密切相关。大部分毒害能够从暴露线虫当代传递给后代。汞暴露对线虫后代寿命的毒害不能够明显恢复。汞暴露线虫后代身体尺寸的缺陷甚至比当代更为严重。此外,高浓度汞暴露通常导致非常纤细的线虫动物出现,且在后代
2、中可观察到更多具有这种表型的线虫。汞暴露导致的线虫身体弯曲和头部摆动频率缺陷在后代中可以大部分或者完全恢复。尽管化学趋向可塑性在汞暴露线虫后代中能够部分恢复,但是化学趋向可塑性仍受到严重的破坏。结论：汞暴露引起的多重生物学毒害可以从暴露当代传递给它们的后代,并且在后代中出现的一些缺陷甚至比当代更为严重。 【关键词】 汞暴露; 多重毒性; 可传递性; 表型; 行为; 秀丽线虫Mercury(Hg) is a hazardous heavy metal, which could be 2released into the environment from both natural and anth
3、ropogenic sources. Natural sources of Hg include volcanic emissions, volatilization from the ocean, and degassing from soil. Use of Hg in industrial such as the manufacture of plastic, chlorine, caustic soda, caustic potash and antifouling paint, is the major anthropogenic sources. Use of Hg in agri
4、culture such as fossil fuel burning, base metal smelting, waste incinerators and Hg based fungicides are other important input sources of Hg in the environments1. In addition, there is a high potential for Hg bioaccumulation and biomagnification in different organisms. The levels of Hg in some comme
5、rcial fish in New Jersey were detected in the range known to cause some sublethal effects in sensitive predatory birds and mammals2. High levels of Hg content were also found in commercial pelagic fish in the Western Indian Ocean, and large fish can naturally bioaccumulate Hg1. Especially, in the su
6、mmer of 2 000, Hg spills were discovered in the basements of some Chicagoarea homes after removal of gas regulators by gas company contractors3. The risk of residential Hg contamination after gas regulator removal ranged from 0.9/1 000 to 4.3/1 000 homes3. So far, Hg has been considered as 3one of t
7、he most serious environmental contamination threats to human, fish and wildlife of the global.Mice, rodents, fish, birds and some other mammals have ever been used as models to evaluate the Hg toxicity and related regulation mechanisms. Elemental Hg is a silvery metal that is liquid at room temperat
8、ure. Human absorption of elemental Hg occurs primarily through inhalation of Hg vapor3. The primary targets of acute exposure to Hg are liver, kidneys and central nervous system in fish, birds and mammals4-5. Inhaled Hg vapor results in accumulation with highest concentrations in the cerebellum and
9、brainstem nuclei of rats and mice6. Hg can cause toxic effects at concentrations even below 1 ppb in water and the effects include loss of appetite, brain lesions, cataracts, abnormal motor coordination and abnormal behavioral changes4-5,7. Aspects affected by Hg exposure also contain the reproducti
10、on, growth, metabolism, blood chemistry, immunity, and oxygen exchange8-11. Several theories about the mechanism of Hg toxicity have already been raised and these theories suggest that the Hg exposure can cause multibiological toxicities by affecting specific signaling 4pathways and lipid peroxidati
11、on12-13. However, for the possible limit of the experimental organisms of mice, fish, birds and other mammals, whether the multibiological toxicities caused by Hg exposure can be transferred from exposed animals to their progeny remains still unclear.Caenorhabditis elegans, a freeliving soil nematod
12、e, has been found favor as a biomarker organism, because it is one of the bestcharacterized animals at the genetic, physiological, molecular, and developmental levels14. C. elegans has the properties of short life cycle, small size, ease of cultivation, a simple cell lineage that has been completed
13、characterized, and behavior easily monitored under the microscope. Moreover, its great potential for forward and reverse genetic analysis make it very powerful for deeply elucidating the mechanisms of metal toxicity. By virtue of these properties, several toxicity tests using C. elegans have been de
14、veloped for ecological risk assessment in soil15-16 and water17-19. Moreover, transgenic hsp16GFPlacZ and hsp16GFP nematodes have been constructed for the study of environmental monitoring and toxicology20-25. In addition, a standardized method for conducting laboratory 5soil toxicity tests using C.
15、 elegans was published in the America Society for Testing and Materials(ASTM) Guide E217201 in 200226.In the present study, we selected the C. elegans organism to examine whether the multibiological toxicities induced by Hg exposure can be transferred from exposed animals to their progeny. Our resul
16、ts suggest that most of these multibiological toxicities induced by Hg exposure can be considered to be transferable from parental generations to their progeny, and some specific defects in progeny appeared even more severe than in their parental generations.1 Materials and methods1.1 ChemicalsThe Hg concentrations used in this report were selected as previously described20,27. Three concentrations of HgCl2 solution were used in
