Cartap is a widely used insecticide which belongs to a member of @entity70260 derivatives and acts on nicotinic @entity934 receptor site. Its effects on aquatic species are of grave concern. To explore the potential developmental @entity137 of cartap, @entity3392 embryos were continually exposed, from 0.5 to 144h post-fertilization, to a range of concentrations of 25-1000microg/l. Results of the experiment indicated that cartap concentrations of 100microg/l and above negatively affected embryo survival and hatching success. Morphological analysis uncovered a large suite of abnormalities such as less melanin pigmentation, wavy notochord, crooked trunk, fuzzy somites, neurogenesis defects and @entity154 . The most sensitive organ was proved to be the notochord which displayed defects at concentrations as low as 25microg/l. Both sensitivity towards exposure and localization of the defect were stage specific. To elucidate mechanisms concerning notochord, pigmentation, and hatching defects, enzyme assay, RT Q-PCR, and different exposure strategies were performed. For embryos with hatching failure, chorion was verified not to be digested, while removing cartap from exposure at early pre-hatching stage could significantly increase the hatching success. However, cartap was proved, via vitro assay, to have no effect on proteolytic activity of hatching enzyme. These findings implied that the secretion of hatching enzyme might be blocked. We also revealed that cartap inhibited the activity of melanogenic enzyme @entity60042 and matrix enzyme @entity12553 oxidase and induced expression of their genes. These suggested that cartap could impaired melanin pigmentation of @entity3392 embryos through inhibiting @entity60042 activity, while inhibition of @entity12553 oxidase activity was responsible for notochord undulation, which subsequently caused somite defect, and at least partially responsible for defects in vasculature and neurogenesis.

Developmental XXXX of cartap on @entity3392 embryos.

@entity154 :: ('MESH:D000013', 'Disease') :: ['vasculature defects'] @entity137 :: ('MESH:D064420', 'Disease') :: ['toxicity'] @entity60042 :: ('30207(Tax:7955)', 'Gene') :: ['tyrosinase'] @entity12553 :: ('CHEBI:32568', 'Chemical') :: ['lysyl'] @entity3392 :: ('7955', 'Species') :: ['zebrafish'] @entity70260 :: ('MESH:C025633', 'Chemical') :: ['nereistoxin'] @entity934 :: ('MESH:D000109', 'Chemical') :: ['acetylcholine']
@entity137 :: (MESH:D064420,Disease) :: ['toxicity']
