Genetic radiosensitivity of specific post-dictyate stages in mouse oöcytes

Abstract
Mouse oocytes were irradiated at known stages during die tyate, the first and second meiotic divisions, and after fertilization, the maturation of the oocytes being controlled by injections of gonadotrophins. Embryonic lethality up to 13 1/2 days was studied after Or, lOOr, and 200r acute X-irradiation. Metaphase and anaphase of the first meiotic division, and metaphase of the second meiotic division were the most sensitive stages, with LD50''s of about. 120r, 130r, and l70r respectively.