著者

Wang Bing

出版者

Journal of Radiation Research 編集委員会

雑誌

Journal of radiation research (ISSN:04493060)

巻号頁・発行日

vol.42, no.1, pp.1-10, 2001-03-15

参考文献数

44

被引用文献数

17 37

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The irradiation of fetuses at the late period of organogenesis has been known to induce a dramatic increase in malformations. The mechanisms involved, however, have remained unclear for a long time. Using the mouse limb bud system, we first found that radiation-induced apoptosis is involved in the malformation, namely, radiation-induced apoptosis in the predigital regions of embryonic limb buds is responsible for digital defects in mice. An examination of embryonic C57BL/6J mice with different <i>p53</i> (<i>trp53</i>) status enabled us to further find that susceptibility to radiation-induced apoptosis in the predigital regions and digital defects depend on both the <i>p53</i> status and the radiation dose; <i>p53</i> wild-type mice appeared to be the most sensitive, while <i>p53</i> knockout mice were the most resistant. These results indicate that p53-dependent apoptosis mediates radiation-induced digital defects in the later organogenesis period. The existence of a radioadaptive response in embryonic mice, which has not been reported so far, was found by irradiating embryos with either 5 cGy or 30 cGy on embryonic day 11 prior to a challenging irradiation at 3 Gy on embryonic day 12. <i>p53</i>-heterozygous embryos did not show the radioadaptive response, indicating the involvement of p53 in the radioadaptive response in embryogenesis.