Jofré Mariana Beatriz, Karasov William H
Area de Biología, Departamento de Bioquímica y Ciencias Biológicas, Universidad Nacional de San Luis, Chacabuco y Pedernera, 5700 San Luis, Argentina.
Chemosphere. 2008 Feb;70(9):1609-19. doi: 10.1016/j.chemosphere.2007.08.002. Epub 2007 Sep 17.
We tested the effect of mono-ortho and di-ortho PCB congeners on northern leopard frog (Rana pipiens) hatching success, survival and sexual development. Embryos and tadpoles were exposed to two levels (0.5 and 50 microg/l) of two PCBs. PCBs 101 and 70 were selected because they were present in amphibians collected in the Fox River-Green Bay ecosystem and they have the theoretical structural requirements to be able to bind to the estrogen receptor and mediate estrogenic responses. The exposure of leopard frog embryos and tadpoles to PCB 70 and 101 did not significantly affect hatchability, survival, deformities or growth. There were significant departures from the expected 50:50 sex ratio in tadpoles/froglets exposed to PCB 101 and PCB 70. In all the cases of significant departure, the bias was towards higher number of females. Decrease in the proportion of male gonads and increase in the proportion of intersex gonads were observed with increasing PCB tissue concentrations. The effects of PCB congeners on sexual differentiation occur at concentrations higher than observed in frogs in the Fox River/Green Bay ecosystem.
我们测试了单邻位和双邻位多氯联苯同系物对北美豹蛙（Rana pipiens）孵化成功率、存活率和性发育的影响。将胚胎和蝌蚪暴露于两种多氯联苯的两个浓度水平（0.5和50微克/升）下。选择多氯联苯101和70是因为它们存在于在福克斯河-绿湾生态系统采集的两栖动物体内，并且它们具备能够与雌激素受体结合并介导雌激素反应的理论结构要求。北美豹蛙胚胎和蝌蚪暴露于多氯联苯70和101对孵化率、存活率、畸形率或生长没有显著影响。暴露于多氯联苯101和多氯联苯70的蝌蚪/幼蛙的性别比例显著偏离预期的50:50。在所有显著偏离的情况中，偏差都倾向于雌性数量较多。随着多氯联苯组织浓度的增加，观察到雄性性腺比例下降，雌雄同体性腺比例增加。多氯联苯同系物对性别分化的影响发生在高于在福克斯河/绿湾生态系统青蛙体内观察到的浓度水平。
