Effects of the organophosphate insecticides diazinon and parathion on bobwhite quail embryos: skeletal defects and acetylcholinesterase activity.

Bobwhite quail eggs were injected at 48 or 72 hr of incubation with various doses of the organophosphate (OP) insecticides diazinon or parathion and the embryos were examined after an additional 48 hr of incubation by both histological and cartilage-staining methods. Bobwhite embryos did not display the notochordal folding or vascular enlargement reported for OP-injected chicken embryos. Cartilage staining of embryos injected with insecticide at 72 hr of incubation and recovered at day 12 of incubation revealed severe shortening and contortion of the vertebral axis, as well as tibiotarsal, rib, and sternum defects.

Teratogenic effects of the organophosphate insecticide dicrotophos (Bidrin): histological characterization of defects.

White Leghorn chicken eggs, specific pathogen free, were treated with the organophosphate insecticide dicrotophos and the early defects thus induced were characterized histologically. Eggs were incubated for 24, 48, 72, or 96 hr, injected with doses of dicrotophos ranging from 250 micrograms to 2.0 mg per egg, and observed after an additional 48 hr of incubation.

The effects of the organophosphate insecticide malathion on very young chick embryos: malformations detected by histological examination.

This histological study sought to determine the nature and incidence of developmental abnormalities induced by one of the reportedly least teratogenic of insecticides injected into very young chick embryos. Using techniques to assure rapid contact between injectant and embryo, eggs incubated for 24, 48, or 72 hr were injected with corn oil or 125 micrograms-4.0 mg malathion.

Notochordal development as influenced by the insecticide dicrotophos (Bidrin).

White Leghorn chicken embryos were treated at different ages with the insecticide dicrotophos to determine the time period of maximum effect upon notochordal development. Doses of insecticide ranging from 250 micrograms to 2.0 mg were injected into eggs at 8, 16, 24, 32, 40, 48, 72, or 96 hr of incubation and the eggs allowed to incubate for an additional 48 hr.

Relationship between insecticide-induced short and wry neck and cervical defects visible histologically shortly after treatment of chick embryos.

In order to clarify the anatomical precursor of short and wry neck, 48-hr chick embryos were injected with 6.25-200 micrograms of the organophosphate (OP) insecticide diazinon and recovered either at 96 hr for histological evaluation or at 19 days for gross observation. Among embryos recovered at 96 hr, all receiving a dose of 25-200 micrograms showed, in serial cross sections, the cervical notochord severely folded in the vertical, horizontal, and diagonal planes and the adjacent neural tube variously folded (often with branching of its canal), deformed by the notochord, rotated, and/or displaced from the midline.