根据一份报告,全世界最常用的杀虫剂阿特拉津(Atrazine)可能与两栖类的内分泌失调有关,而且可能对全世界两栖类物种的衰退有贡献。这种化学杀虫剂在欧盟被禁用,但是美国环保署在2006年得出结论说还没有足够的数据可以确定阿特拉津是否会影响到两栖类的发育。
Tyrone Hayes及其同事检查了接触阿特拉津对非洲爪蛙的一个全雄性种群的长期影响。这组科学家比较了40只在遗传上是雄性的对照组蛙和从孵化到完全性成熟阶段在有阿特拉津的环境下培养的40只在遗传上是雄性的蛙,对于后者,阿特拉津的浓度处于在美国环保署规定的饮用水标准之下的地区这种动物全年遇到浓度范围内。所有的成年对照组蛙表现出了典型的雄性外部特征,但是接触阿特拉津的蛙的10%发育成了具有功能的雌性,后者成功地与未接触阿特拉津的雄性交配,并产出了可孵化的卵。
这组作者说,接触阿特拉津的雄蛙遇到了睾丸激素水平的抑制,性腺尺寸减少,雌性化的喉发育,交配行为受到抑制,精液产量减少,而且繁殖力下降。(生物谷Bioon.com)
生物谷推荐原始出处:
PNAS March 1, 2010, doi: 10.1073/pnas.0909519107
Atrazine induces complete feminization and chemical castration in male African clawed frogs (Xenopus laevis)
Tyrone B. Hayesa,1, Vicky Khourya,2, Anne Narayana,2, Mariam Nazira,2, Andrew Parka,2, Travis Browna, Lillian Adamea, Elton Chana, Daniel Buchholzb, Theresa Stuevea, and Sherrie Gallipeaua
aLaboratory for Integrative Studies in Amphibian Biology, Department of Integrative Biology, Museum of Vertebrate Zoology, Energy and Resources Group, Group in Endocrinology, and Molecular Toxicology Group, University of California, Berkeley, CA 94720-3140; and
bDepartment of Biological Sciences, University of Cincinnati, Cincinnati, OH 45221
The herbicide atrazine is one of the most commonly applied pesticides in the world. As a result, atrazine is the most commonly detected pesticide contaminant of ground, surface, and drinking water. Atrazine is also a potent endocrine disruptor that is active at low, ecologically relevant concentrations. Previous studies showed that atrazine adversely affects amphibian larval development. The present study demonstrates the reproductive consequences of atrazine exposure in adult amphibians. Atrazine-exposed males were both demasculinized (chemically castrated) and completely feminized as adults. Ten percent of the exposed genetic males developed into functional females that copulated with unexposed males and produced viable eggs. Atrazine-exposed males suffered from depressed testosterone, decreased breeding gland size, demasculinized/feminized laryngeal development, suppressed mating behavior, reduced spermatogenesis, and decreased fertility. These data are consistent with effects of atrazine observed in other vertebrate classes. The present findings exemplify the role that atrazine and other endocrine-disrupting pesticides likely play in global amphibian declines.