Key Laboratory of Developmental Genes and Human Disease in Ministry of Education, Department of Genetics and Developmental Biology, Southeast University Medical School, Nanjing 210009, China.
Environ Toxicol Pharmacol. 2009 Jul;28(1):104-10. doi: 10.1016/j.etap.2009.03.006. Epub 2009 Mar 17.
Previous studies have revealed that metal exposure will cause severe deficits in perception behaviors. Here we investigated the effects of metal (Hg, Cu, Ag, and Cr) exposure on thermotaxis to cultivation temperature in Caenorhabditis elegans. Our data suggest that exposure to higher concentrations of examined metals induced severe deficits in thermotaxis, and a significant reduction in thermotaxis could be even observed in nematodes exposed to 2.5μM of Hg. Moreover, exposure to higher concentrations of examined metals and 2.5μM of Hg induced significant decreases in relative intensities and relative sizes of fluorescent puncta of cell bodies in AFD thermosensory neurons. In addition, exposure to higher concentrations of examined metals resulted in a significant reduction in relative intensities and relative lengths of sensory endings in AFD neurons. Furthermore, the relative transcript levels of ttx-1, which functions in specifying the fate of AFD neuron, were significantly decreased in nematodes exposed to 2.5μM of Hg, and 50 and 100μM of examined metals. Thus, metal exposure at high concentrations will induce the severe deficits in thermotaxis to cultivation temperature possibly by altering the morphology or development of AFD neuron and damaging the molecular basis for function of AFD neuron in nematodes.
先前的研究表明，金属暴露会导致感知行为严重缺陷。在这里，我们研究了金属（汞、铜、银和铬）暴露对秀丽隐杆线虫对培养温度的趋热行为的影响。我们的数据表明，暴露于较高浓度的研究金属会导致趋热行为严重缺陷，甚至在暴露于 2.5μM 汞的线虫中也观察到趋热行为显著减少。此外，暴露于较高浓度的研究金属和 2.5μM 汞会导致 AFD 热敏神经元体细胞荧光斑点的相对强度和相对大小显著降低。此外，暴露于较高浓度的研究金属会导致 AFD 神经元感觉末梢的相对强度和相对长度显著减少。此外，在暴露于 2.5μM 汞和 50μM 和 100μM 研究金属的线虫中，ttx-1 的相对转录水平显著降低，ttx-1 基因在指定 AFD 神经元命运中起作用。因此，高浓度金属暴露可能通过改变 AFD 神经元的形态或发育，并损害 AFD 神经元功能的分子基础，导致对培养温度的趋热行为严重缺陷。
