戊唑醇对秀丽线虫的生殖毒性作用

目的：探讨戊唑醇对模式生物秀丽线虫的生殖毒性作用。方法：L2期的N2、him-5（e1490）雄虫分别暴露于0.1、1.0和10.0 μg/L浓度的戊唑醇中到L4期。通过测定野生型N2线虫的后代数目与世代时间判断戊唑醇是否存在生殖毒性，通过突变体him-5（e1490）与fog-2（q71）杂交的后代数目判断是否具有雄性生殖毒性；通过检测him-5（e1490）雄虫有丝分裂区细胞、减数分裂区细胞、精细胞数目以及相关基因的表达水平研究戊唑醇对精子发生过程的影响；通过对him-5（e1490）雄虫精子细胞的形态、畸形率、活化能力以及相关基因表达水平的检测研究戊唑醇对精子形成过程的影响。相关基因表达水平用实时荧光定量PCR进行测定。结果：与对照组比较，暴露后的L4期秀丽隐杆线虫在戊唑醇剂量为10.0 μg/L时后代数目显著降低（P < 0.05）；1.0和10.0 μg/L戊唑醇剂量组可以使him-5（e1490）与fog-2（q71）的杂交后代数目降低（P均 < 0.05），并可致秀丽线虫的有丝分裂区细胞数、减数分裂区细胞数、总生殖细胞数以及精细胞数目降低（P均 < 0.05），daf-2、akt-1、daf-16 mRNA在1.0和10.0 μg/L剂量组的表达量均上升（P均 < 0.05）；age-1 mRNA在0.1~10.0 μg/L染毒剂量组表达量均明显下降（P < 0.05或P < 0.01）；与对照组相比，0.1、1.0、10.0 μg/L剂量组精细胞的直径与精子横截面积均明显减小（P均 < 0.05），1.0、10.0 μg/L剂量组精细胞的活化能力均明显降低（P均 < 0.05）；try-5，spe-4，spe-6，fer-1 mRNA的表达量均明显上升（P < 0.05或P < 0.01），swm-1 mRNA在1.0 μg/L剂量组基因的表达量上升（P < 0.01）。结论：戊唑醇通过影响秀丽线虫精子的发生以及精子的形成过程产生生殖毒性。

Reproductive toxicity of tebuconazole on male Caenorhabditis elegans

OBJECTIVE:The aim of this study was to investigate reproductive toxicity of tebuconazoleine tebuconazoleb (TEB) in Caenorhabditis elegans(C.elegans).METHODS:Wild-type(N2) and him-5(e1490) strains from L2-larvae to L4-larvae stages were exposed to TEB at concentrations of 0.1,1.0 and 10.0 μg/L.Brood size and generation time measurements were used to evaluate fertility defects in nematodes.Furthermore,the number of outcross progeny was used to detect reproductive toxicity on male worms.Multiple endpoints were employed to evaluate defects on spermatogenesis,including the number of germ cells in mitosis and meiosis zoon,the number of germs in the germ line and the expression levels of related genes.Sperm size,morphology and activation ability were used to evaluate the adverse effect on spermiogenesis.The level of related genes was detected by real-time fluorescence quantitative PCR.RESULTS:The brood sizes at a concentration of 10.0 μg/L and the number of outcross progeny at concentrations more than 1.0 μg/L were reduced.However,generation times were not changed compared with that from the control group.The number of total germ cells,mitotic cells,meiotic cells and spermatids were less than that from the control group at concentrations of more than 1.0 μg/L.mRNA levels of daf-2,akt-1,and daf-16 were significantly increased at concentrations of 1 and 10 μg/L.Additionally,the mRNA level of age-1 was decreased at the concentrations of 0.1 to 10.0 μg/L compared to the control group.The sperm diameter and cross-sectional sperm area were reduced at concentrations of 0.1-10.0 μg/L,the activation ability of the sperm was declined in the 1.0 μg/L and 10.0 μg/L treatment groups.The expression level of try-5,spe-4,spe-6,fer-1 mRNA were increased significantly and swm-1 mRNA was decreasedcompared with the control group.CONCLUSION:TEB exposure causeds reproductive toxicity in Caenorhabditis elegans by affecting spermatogenesis and spermiogenesis.