Heritable malformations in the progeny of the male medaka (Oryzias latipes) irradiated with X-rays.
Heritable malformations were examined in the progeny of X-irradiated male medaka (Oryzias latipes) by three-generation crosses. Two X-irradiated male fish were pair-mated with non-irradiated females to produce F1 founders, and each F1 fish was pair-mated with a non-irradiated fish to produce F2 progeny. For detection of recessive mutations, pair-matings between F2 siblings were performed for each F1 family. Morphogenesis of the embryos of each generation was observed using a stereomicroscope, throughout the entire period of embryonic development. In the F1 embryos, the frequencies of dominant lethals and malformations were increased by the X-irradiation. Two out of 30 F1 pairs produced a number of malformed and lethal F2 embryos, indicating inheritance of high rates of the dominant lethals in the two F1 families. Moreover, F2 sib-pairs offspring of which exibited high rates of dominant lethals were found in 10 out of 28 F1 families. Recessive lethal mutations, which were associated with a particular phenotype, were found in 2 out of the 28 F1 families. These results indicate that the heritable malformations induced by X-irradiation can be studied in the medaka.
Ishikawa
Y
Y
Division of Biology, National Institute of Radiological Sciences, Chiba, Japan.
Hyodo-Taguchi
Y
Y
D000016:Abnormalities, Radiation-Induced; D000818:Animals; D003433:Crosses, Genetic; D004625:Embryo, Nonmammalian / Q000528:radiation effects; D005314:Embryonic and Fetal Development / Q000528:radiation effects; D005260:Female; D005799:Genes, Dominant; D005804:Genes, Lethal; D005808:Genes, Recessive; D008297:Male; D009990:Oryzias; D018812:Paternal Exposure; D011247:Pregnancy; D013087:Spermatids / Q000528:radiation effects; D013093:Spermatogonia / Q000528:radiation effects; D013094:Spermatozoa / Q000002:abnormalities / Q000528:radiation effects; D014965:X-Rays