Toxicity and estrogenic endocrine disrupting activity of phthalates and their mixtures.

Phthalates, widely used in flexible plastics and consumer products, have become ubiquitous contaminants worldwide. This study evaluated the acute toxicity and estrogenic endocrine disrupting activity of butyl benzyl phthalate (BBP), di(n-butyl) phthalate (DBP), bis(2-ethylhexyl) phthalate (DEHP), diisodecyl phthalate (DIDP), diisononyl phthalate (DINP), di-n-octyl phthalate (DNOP) and their mixtures. Using a 72 h zebrafish embryo toxicity test, the LC50 values of BBP, DBP and a mixture of the six phthalates were found to be 0.

A cascade of irx1a and irx2a controls shh expression during retinogenesis.

In animal retina, hedgehog expression drives waves of neurogenesis, but genetic programs that control its expression during retinal neurogenesis are poorly elucidated. We have previously reported that irx1a is required for propagation of the sonic hedgehog (shh) expression waves in developing zebrafish retina. Here, we found that irx2a is expressed in the developing retina and that knockdown of irx2a results in a retinal phenotype strikingly similar to that of irx1a morphants.