阿特拉津对泥鳅性腺及性别分化相关基因的影响

以泥鳅为材料,首先确定了阿特拉津对泥鳅的急性毒性.在此基础上采用组织学切片和实时荧光定量PCR(qRT-PCR)的方法研究了阿特拉津长期处理对泥鳅性腺形态和性别分化相关基因表达模式的影响,以期准确评估阿特拉津的环境毒性和对水生生物生殖发育的作用.结果表明:阿特拉津对泥鳅的24h、48h、96h的半数致死浓度(LC50)分别为31.60mg/L、26.82mg/L、18.98mg/L,安全质量浓度(SC)为5.8mg/L.随着阿特拉津浓度的增加和处理时间的延长,泥鳅的死亡率明显的升高.通过组织学研究发现高浓度的阿特拉津(2.68 mg/L)处理泥鳅21d能够抑制泥鳅精巢精子的发生,促进卵巢细胞的发育.同时qRT-PCR结果显示:与对照组相比不同剂量的阿特拉津(2.68mg/L,0.268mg/L,0.0268mg/L)能够显著的诱导细胞色素P450芳香化酶基因(cyp19a),类固醇生成因子(sf1)的表达,对抗缪勒氏管激素(amh)有显著的抑制效应.因此,阿特拉津对泥鳅有明显的外源雌激素效应;通过干扰类固醇激素合成基因的表达影响生殖细胞的生成;也通过某种未知的机制干扰性别分化上游基因的表达,从而影响性腺分化.

Effects of Atrazine on Sex Differentiation and Expression Pattern of Related Genes in Loach

We used loach as experimental materials to confirm the acute toxicity of atrazine firstly.In order to correctly estimate the environmental toxicity of atrazine and the effects on aquatic organisms reproductive development,we explored the long-term treatment effects of atrazine on gonad shape and sex differentiation related gene expression by histology and real-time quantitative PCR(qRT-PCR).On the basis of acute toxicity experiment,the experimental results showed that:24h,48hand96hLC50 of atrazine were 31.60mg/L,26.82mg/L and 18.98mg/L,respectively and the safety concentration(SC)was 5.8mg/L.With the increase of concentration of atrazine and the extension of exposure time,the mortality rates of loach significantly increased.We found that loach was exposed to high concentration of atrazine(2.68mg/L)for 21 dcould inhibit the occurrence of spermatogenesis and promote the development of ovarian cells by histological experiments.At the same time,the results of qRT-PCR showed that:different doses of atrazine(2.68mg/L,0.268mg/L,0.0268mg/L)could significantly promote the expression of cytochrome P450 aromatase gene(cyp19a),steroidogenic factor(sf1)in comparison with the control group,and had a significant inhibitory effect on Anti-Müllerian hormone(amh).In conclusion,atrazine had obvious acute toxic effects on loach and also had function of exogenous estrogen to inhibit a male sex key gene amh and promote the expression of ovarian marker gene cyp19 a.Therefore,atrazine had significant exogenous estrogen effect produced on loach.It affected the production of germ cells by disturbing the expression of steroidogenic genes.It also interfereed with the expression of upstream genes in sex differentiation by some unknown mechanism,which can affect the differentiation of gonad.