Adaptive response in embryogenesis. III. Relationship to radiation-induced apoptosis and Trp53 gene status.
We reported previously that a radiation-induced adaptive response existed in the late period of embryogenesis, and that radiation-induced apoptosis in the predigital regions was responsible for digital defects in embryonic ICR mice. To investigate the possible involvement of the Trp53 gene and radiation-induced apoptosis in radiation-induced adaptive responses in embryogenesis, the present study was conducted using Trp53 wild-type (Trp53(+/+)) and Trp53 heterozygous (Trp53(+/-)) embryonic mice of the C57BL/6 strain. The existence of a radioadaptive response in the Trp53(+/+) embryonic mice was demonstrated by irradiating the embryos with 5 or 30 cGy on embryonic day 11 prior to a challenging irradiation at 3 Gy on embryonic day 12. The two conditioning doses at 5 and 30 cGy significantly suppressed the induction of apoptosis by the challenging dose in the predigital regions of limb buds in the Trp53(+/+) embryonic mice, while no such effect was found in the Trp53(+/-) embryonic mice. These findings indicate that induction of a radioadaptive response in embryogenesis is related to Trp53 gene status and the occurrence of radiation-induced apoptosis.
Wang
B
B
Division of Radiobiology and Biodosimetry, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-8555, Japan.
Ohyama
H
H
Haginoya
K
K
Odaka
T
T
Itsukaichi
H
H
Yukawa
O
O
Yamada
T
T
Hayata
I
I
D000016:Abnormalities, Radiation-Induced / Q000209:etiology* / Q000235:genetics / Q000473:pathology; D000222:Adaptation, Physiological; D000818:Animals; D017209:Apoptosis / Q000528:radiation effects*; D019583:Dose Fractionation, Radiation; D004622:Embryo, Mammalian / Q000528:radiation effects*; D005314:Embryonic and Fetal Development / Q000235:genetics / Q000528:radiation effects*; D005121:Extremities / Q000196:embryology / Q000528:radiation effects; D005260:Female; D005313:Fetal Death / Q000209:etiology* / Q000235:genetics / Q000473:pathology; D016158:Genes, p53; D020022:Genetic Predisposition to Disease; D005865:Gestational Age; D017880:Limb Deformities, Congenital / Q000209:etiology; D051379:Mice; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D018345:Mice, Knockout; D011833:Radiation Injuries, Experimental / Q000196:embryology* / Q000235:genetics / Q000473:pathology; D011836:Radiation Tolerance / Q000235:genetics*; D016159:Tumor Suppressor Protein p53 / Q000172:deficiency / Q000502:physiology*
D016159:Tumor Suppressor Protein p53