Blastular arrest and chromosome abnormalities produced by x‐rays in two amphibians: Rana pipiens and Xenopus laevis

Abstract Production of chromosomal abnormalities by x‐raying Amphibian zygotes is not necessarily followed by blastular arrest. At an x‐ray dose that produces blastular arrest in 20% of the irradiated embryos, over 90% of the embryos were found to contain cells with gross chromosome aberrations. Different pregastrular stages are differentially sensitive towards x‐ray production of blastular arrest.