The effects of aphidicolin, an inhibitor of DNA replication, on sea urchin development

Abstract

SUMMAR Y Aphidicolin, an inhibitor ofDNA polymerase a. arrests DNA synthesis without affecting RNA and protein synthesis at ail stages of sea urchin development. Cleavage is quickly stopped and hatching is prevented by the présence of the drug at 2 /u,g/ml. Treatment with aphidicolin of young blastulae prevents gastrulation. but inhibition of archenteron invagination and skeleton formation is incom plète when the drug is added to late blastulae or early gastrulae. The rôle of cell division in gastrulation is discussed.

Dependence of the timing system regulating the onset of gastrulation on cytoplasmic, but not nuclear, activities in the Xenopus embryo

“…Kobayakawa & Kubota (1981) concluded that, in newt embryos, the timing of the onset of gastrulation is not controlled by the timing of MBT or the total number of cells or cell divisions but, possibly, by the absolute time from fertilization. This finding is consistent with other reports showing that gastrulation began, and was often completed, in amphibian and echinoderm embryos in the absence of nuclear replication and cell division when administered with inhibitors from around the presumptive start of gastrulation (Cooke 1973; Brachet & de Petrocellis 1981; Stephens et al . 1986; Harris & Hartenstein 1991; Rollin & Andrews 1991).…”

Sea Urchin Embryo as a Model Organism for the Rapid Functional Screening of Tubulin Modulators

“…When applied to free-swimming blastulae, DNA-targeting drugs did not induce any changes in swimming pattern, except for the lethal concentrations resulting in embryo immobilization and death. Similar effects of aphidicolin (an inhibitor of DNA polymerase a) (32), 5-azacytidine (an inhibitor of DNA methylation) (33), and DNA intercalator doxorubicin (11) have been observed on sea urchin S. granularis, Psammechinus miliaris, A. punctulata , and P. lividus embryos. These results further supported our observation that the embryo spinning phenomenon is unique to the tubulin destabilizing drugs.…”

The Effects of Methoxychlor on Early Sea Urchin Development

“…By 48 hr many of the embryos exposed to 100 ppm MXC displayed abnormal gut formation. Since Bresch and Arendt (1977) have reported MXC to inhibit DNA synthesis in early sea urchin embryos and DNA synthesis inhibitors such as aphidicolin have been shown to inhibit gut formation in sea urchin embryos (Stephens et al, 1986;Brachet and De Petrocellis, 1981), it is conceivable that this may be the basis of the failure of gut formation in these MXC-exposed embryos.…”