久效磷对秀丽隐杆线虫运动、学习和觅食行为的影响

久效磷(MCP)是一种广谱类内吸附性有机磷农药和潜在的神经毒剂,能够对非靶生物产生神经毒性作用,而行为毒性是神经毒性的主要表现形式.以运动、学习与觅食行为、乙酰胆碱酯酶活性为指标,研究了久效磷对非靶生物——秀丽隐杆线虫(Caenorhabditis elegans,下称线虫)行为的影响.结果显示:经0.5、5.0和50.0 mg/L久效磷暴露后,各暴露组线虫头部摆动和身体弯曲频率均极显著降低,0.5 mg/L暴露组线虫向前摆动频率显著减少,5.0和50.0 mg/L暴露组线虫向前摆动频率极显著减少;5.0和50.0 mg/L暴露组线虫在Na Cl存在和缺少食物条件下,对Na Cl的趋向性极显著升高;与对照组相比,50.0 mg/L暴露组线虫菌落接触率在2、4、6、8 h时均显著降低,在24 h时极显著降低;各暴露组线虫的乙酰胆碱酯酶活性均受到极显著抑制.表明久效磷能够导致线虫运动、学习与觅食行为的严重缺陷,乙酰胆碱酯酶活性抑制与久效磷对线虫运动行为的影响呈正相关,与其学习行为的影响呈负相关.

Effects of Monocrotophos on the Locomotion, Learning and Foraging Behavior of Caenorhabditis elegans

As a broad spectrum systemic organophosphorus pesticide (OPs), monocrotophos (MCP) is a potent neurotoxicant, which could result in neurotoxicity to non-target organisms. Behavioral toxicity is the main form of expression in neurotoxicity. The effects of MCP on the behaviors of a non-target organism, Caenorhabditis elegans, were studied using locomotion, learning, foraging behavior and acetylcholinesterase (AChE) activity as the endpoints. The results showed that after exposure to MCP (0.5,5.0 and 50.0 mg/L), there was a highly significant decrease in both head thrashes and body bends in all treated groups. The treatment of MCP also reduced the activity of forward turns, which was significant for 0.5 mg/L MCP and highly significant for 5.0 and 50.0 mg/L MCP. Meanwhile, the treatment of 5.0 or 50.0 mg/L MCP significantly enhanced the chemotaxis towards NaCl. Moreover, compared with the control groups of 2,4, 6,8 and 24 h, the attainment levels of C. elegans treated with 50.0 mg/L MCP were significantly decreased at 2,4, 6, and 8 h and extremely decreased at 24 h. In addition, the AChE activity of C. elegans significantly decreased in all treated groups in a dose-dependent manner. MCP caused obvious, severe defects of locomotion, learning and foraging behaviors in C. elegans, and there was a positive correlation between the inhibition of AChE activity and the effect of MCP on locomotion behavior, and a negative correlation between the inhibition of AChE activity and the effect of MCP on learning behavior.