Itow T, Loveland RE, Botton ML
Department of Biology, Faculty of Education, Shizuoka University, Ohya 836, Shizuoka City, Shizuoka 422-8529, Japan.
Arch Environ Contam Toxicol. 1998 Jul;35(1):33-40. doi: 10.1007/s002449900345.
We examined the effects of heavy metals on the development of horseshoe crabs using bioassays in which embryos at different stages were exposed either continuously or for 24 h. Abnormalities included segment-defective embryos, double embryos, embryos with abnormal eye areas, and no-posterior embryos. In terms of their ability to affect normal development, the pollutants are ranked as follows: Hg >== organotin > Cr falling dots Cd > Cu > Pb > Zn. Organotin treatment was associated with a high frequency of abnormal eye embryos and Hg with segment-defective embryos. The specific cause of segment-defective malformations by Hg was investigated by using SH inhibitors and cytochalasin B, an inhibitor of microfilaments. These inhibitors induced Hg-type segment-defective embryos; thus, Hg may also act by inhibiting SH-SS exchange and blocking morphogenetic movements. Horseshoe crab embryos from Delaware Bay and Sandy Hook Bay, New Jersey, were examined for developmental abnormalities. Malformed embryos were extremely rare (<0.6%) at five beaches along Delaware Bay as well as Sandy Hook Bay, suggesting that these horseshoe crab spawning areas are relatively unpolluted by heavy metals.
我们通过生物测定法研究了重金属对鲎发育的影响，在该生物测定法中，处于不同阶段的胚胎被连续暴露或暴露24小时。异常情况包括节段缺陷胚胎、双胚胎、眼区异常的胚胎以及无后胚胎。就其影响正常发育的能力而言，污染物的排名如下：汞≥有机锡＞铬＞镉＞铜＞铅＞锌。有机锡处理与眼异常胚胎的高频率相关，汞与节段缺陷胚胎相关。通过使用巯基（SH）抑制剂和细胞松弛素B（一种微丝抑制剂）研究了汞导致节段缺陷畸形的具体原因。这些抑制剂诱导出了汞型节段缺陷胚胎；因此，汞也可能通过抑制SH-SS交换和阻断形态发生运动而起作用。对来自特拉华湾和新泽西州桑迪胡克湾的鲎胚胎进行了发育异常检查。在特拉华湾沿岸以及桑迪胡克湾的五个海滩上，畸形胚胎极为罕见（＜0.6%），这表明这些鲎产卵区相对未受重金属污染。
