The Input Way Of Methylmercury On Hibernating Rana Chensinensis And The Preliminary Study Of The Level Of DNA Methylation

Methylmercury is a potent toxicant. It can enter into the animals′bodies by the food chain, and accumulate by bioconcentration and biomagnification. This is a fact which has been proved many times. The aim of this article is to see whether the methylmercury can be enriched from the living environment. Using indoor Microcosm Device simulates the hibernating Rana chensinensis and the living environment. Rana chensinensis have been poisoned with methylmercury in order to discuss the effect of accumulation and biomagnification. In order to text the results, the hibernating Rana chensinensis have been collected from the river near the gold-mining areas in HuaDian of Jilin Province.The experiment has two gradients: 0.01μgï¹'L-1 and 0.03μgï¹'L-1, adding a certain amount of methylmercury everyday, sampling and determining 4 parts of Rana chensinensis (skin, muscle, viscera and brain), determining methylmercury in sediment too. Both of the concentration of methylmercury in Rana chensinensis and the bioaccumulation factor should be calculated. The results show that: with the days increased, the concentration of methylmercury increased, then decreased rapidly after reach the peak. At the end of the experiment the concentration of methylmercury slowly uplifted. It is shows the emergency response and detoxicate reaction for methylmercury and the accumulation effect of methylmercury. The highest content of methylmercury is in the brain of Rana chensinensis; however the lowest is in the skin. It is shows the truth that methylmercury can be enriched in the brain easily and the skin is the input channel of methylmercury. The main source of methylmercury is from the water. We collected Rana chensinensis from three different places around the gold-mining areas. Each place collected 10-11samples.The samples can be divided into four parts (skin, muscle, viscera and brain).We measured each part of the samples, water and sediment. The results of the experiment show: The Rana chensinensis which have been contaminated from gold-mining areas have the same accumulate trends. The methylmercury can enter into Rana chensinensis by sediment and water, and then permeate into the skin of the Rana chensinensis.The rates of DNA methylation in the muscle of Rana chensinensis have been measured between the gold polluted regions and clean region in order to investigate the DNA of Rana chensinensis which have been polluted by methylmercury. Rana chensinensis can be collected from different regions. The High Performance Liquid Chromatography (HPLC) can be used to measure the rate of DNA methylation after abstracting DNA. The experimental results show that: methylmercury can make the DNA methylation rates of Rana chensinensis reduce at different levels. The degree of reduction has a certain relationship with pollution.