Abstract
Comparisons of RBE values of 14MeV fast neutrons for the induction of dominant lethals and visible recessive mutations in mature sperm of the silkworm were studied. The main conclusions to be drawn from the results presented are that the RBE of fast neutrons for the dominant lethals (RBE: 10.2) is about 2.1 times that of the mosaics (RBE: 4.8), and the RBE for the mosaics is the same or less than that for the complete mutations (RBE: 6.0).
Considering these findings and others, it seems that the nature of radiation-induced complete and mosaic mutations at the pe and re loci of the mature sperm of the silkworm, at doses below about 5kR, could have occurred as a mixture of DNA strand change type mutations and chromosomal type such as deletion and small deficiency, whereas the dominant lethals may correspond to chromosomal changes.
