| Parabens (also known as enhanceparaben) are the most widely and frequently used food antiseptic additives in the word. It consists of methyl paraben (MP), ethyl paraben (EP), propyl paraben (PP) and butyl paraben (BP). This kind of materials is not only colorless and odorless, but also has remarkable antibacterial effect, so has been used widely in many foods, pharmaceuticals, cosmetics and toiletries as safe and effective preservatives for many years. In China, the methyl paraben, ethyl paraben and their sodium salt are allowed in standards on the use of food additives.Part of the metabolites of parabens can accumulate in the body after absorption, and due to the widely used in different fields, this material also could be detected in the water, air and soil. These all result in the increasing of the way human expose, the absorbing capacity increased year by year. Recent studies have shown that parabens possess the obvious oestrogenic activity, which has adverse effect on the reproduction, development and health.Drosophila melanogaster is one of the most important model organisms in biological study. It has many advantages than other creatures, include smaller size, shorter lifecycle, better fertility, more offspring, easier to raise and less cost, we could raise them in laboratory convenient, and Drosophila is the well experiment model for the mechanism research of some human disease.In our subject, we discussed the toxicology effect of ethyl paraben (EP), using Drosophila as material, studied the influences of different concentrations EP on the longevity and the expression of apoptosis related gene reaper in male and female Drosophila, and finally analyzed the relationship between longevity and gene expression. The male and female Drosophila which eclosion in8hours were treated with different concentrations EP (0.02%,0.05%,0.10%,0.20%), on the one hand, we research the influence of EP on longevity, testing the survival rate, mean lifespan, maximum lifespan, half death time and90%death time; on the other hand, research the influence of EP on expression of apoptosis related gene reaper, testing the change of gene expression under different treat time. At last, we combined the change of longevity and gene expression mode to discuss the toxicity of EP on Drosophila. The results show:(1) Treated the male and female Drosophila which eclosion in8hours with different concentrations EP. The results showed that the survival rate, mean lifespan, maximum lifespan, half death time and90%death time were different in each EP group, and were all significantly lower than control group. Along with the concentration increased, the survival rate and longevity gradually reduced, the EP toxic effect became more obvious, which reflected the doses-effect relations. It illustrated that EP reduced the survival rate of Drosophila, shortened the longevity.(2) Treated the male and female Drosophila which eclosion in8hours with different concentrations EP until10days,20days,30days, designed the specificity primers of apoptosis related gene reaper and reference gene GAPDH, using RT-PCR and Real-time PCR to test the Drosophila reaper gene mRNA expression level under different EP concentrations and different treating days. The result illustrated that the expression level of reaper in control group had no obvious change with the time increased, but EP could lead to the expression mode change. Under a short time, low concentration stimulation, the expression level of reaper could be induced by EP, along with the increasing of concentration and time, the inhibitory action of EP on reaper expression became more evident.(3) Comprehensive analysis the effects of different concentrations EP on longevity and the expression of reaper in drosophila, we could conclude that the disorder of cell apoptosis in Drosophila may be one of the molecular mechanism of EP lead to shorten the longevity. |
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