| Phenolic is a environment pollutant commonly found in the natural environment which is one of important factors that affect animal growth and development, therefore, all of such facts leading to the sharp decrease in the number of animals. BPA is one of many diphenylalkanes that are raw materials for the production of polymers, and are used commercially in plastics and coatings in the dental and food industry. Recently, Rana chensinensis is a valuable economic wild frog, however, the mount of this significant specie has decreased sharply caused by the widely utilization of such pollutant. In this research, we carry out the experiments of toxicity and trans-generation effects on Rana chensinensis, which would reveal that the acute toxicity of BPA on the Rana chensinensis and effects on its growth and development ,moreover,including the growth , development and trans-generation of gonad differentiation of the filial generation. We could supply lots of scientific basis to control Phenolic in natural environment.In this study, with the method of water exposure of BPA ,Rana chensinensis tadpoles were continuously exposed within the concentration of 10-5,10-6,10-7 mol·L-1 BPA until it has been entered from the stage 26 to stage 66. Then, its weight, length and time of metmaoprhosis were examined at stage of tarsometatarsus elongation,fore-limb exsertion and metamorphosis complement.Moreover, Rana chensinensis, its female adults were exposed within the concentration of 10-5,10-6,10-7 mol·L-1 BPA, lasting 60d. Then, its tadpoles have been also exposed into BPA and have analyzed the developing time, body length, weight and the trans-generation effects respectively. To investigate the trans-generation of gonadal development affected by BPA via exposing the female adults into BPA, we checked its gonadal morphology and statistically analyzed the off-spring female ratio. The results were all follows:1. A standard method was used to evaluate the acute toxicity of BPA on Rana chensinensis tadpoles .The results showed that the regress equation between the death probability of Rana chensinensis tadpoles and the concentration logarithm of BPA were y= 16.915 x-4.1157,y=22.110 x-6.1905,y=20.766 x-5.3871,y=20.715 x-5.351, respectively for 24,48,72,96 h.. The mean LC50 values were 3.47×10-5,3.28×10-5,3.20×10-5,3.16×10-5 mol·L-1 respectively. Where, the mean SC(safe concentration)values was 8.8×10-6 mol·L-1 .2. The experiment of the chronic toxicity of BPA on Rana chensinensis tadpoles showed that:BPA, under the safe concentration, itself did not affect mortality of Rana chensinensis tadpoles. The time of its developing between the experimental group and control group, which have represented an obvious consequence that the time of experimental group treated by the different concentration of BPA would much longer than others, meanwhile, it is also reflected its delayed developing time, decrease of the body length and weight as well. Technically, the overall phenomenon of developing is slower as the concentration improves.3. The experiment of trans-generation effects of BPA on Rana chensinensis tadpoles showed that: BPA, under the safe concentration, itself has little influence on the hatchability of tadpoles. The time of its developing between the experimental group and control group, which also have revealed an obvious consequence that the time of experimental group treated by the different concentration of BPA would much longer than others, meanwhile, it is also reflected at its delayed developing time and decreased weight as well, but the body length, it has no significant variation with the former group. Meanwhile, the variation of body-weight during the developing time has always occurred at later-period with a higher concentration.4. There is little significant change at gonadal morphology and micro-structure of the off-spring frog via exposing the female adults into BPA. The result of statistically analyzing the off-spring female ratio showed that:. the off-spring female ratio is higher with the concentration of 10-6mol·L-1 when only the female adults were treated, another group, the female adults and off-spring were all treated, all experimental group female ratio is greatly higher; The last group, the off-spring only treated, the off-spring female ratio is obviously higher as the concentration increases and all the groups treated by BPA have showed a similar trend.5. To further understand the endocrine disruptors of trans-generations, we investigated the liver expression of vitellogenin baby-frog which was treated by BPA with the method of Immunohistochemical. The results showed that: there is a higher result of expression of vitellogenin within the experiment group, especially the significant difference occurred at 10-5and 10-6 mol·L, which revealed that the endocrine of the off-springs was largely affected by the toxicity of the mother body.In a word, it is found that BPA may cause Rana chensinensis to die at high concentrations, and it also has an impact on the growth development of Rana chensinensis in low concentrations. Meanwhile, its toxicity has a strong ability to transfer it into their off-springs which could affect the development, gonadal differentiation and endocrine activity of tadpoles. |
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