Chambers J R, Chapman A B
Genetics. 1977 Feb;85(2):309-17. doi: 10.1093/genetics/85.2.309.
The genetic effects of one generation of spermatogonial X-irradiation in rats, by a single dose of 600r in one experiment and by a fractionated dose of 450r in another, were measured in three generations of their descendants. Estimates of dominant lethal mutation rates--(2 to 3) X 10-4/gamete/r--from litter size differences between irradiated and nonirradiated stock were consistent with previous estimates from rats and mice. Similar consistency was found for estimates of sex-linked recessive mutation rates--(1 to 2) X 10-4 chromosome/r--from male proportions within strains; however, when measured in crossbreds the proportion of males was higher in the irradiated than in the nonirradiated lines. This inconsistency in results is in keeping with the contradictory results reported for recessive sex-linked lethal mutation rates in mice. The effects used to estimate recessive lethal mutation rates which were unusually high--(2 to 14) X 10-4/gamete/r--were not significant. Other factors that could have contributed to the observed effects are postulated.
在一项实验中，对大鼠进行单次600伦琴的精原细胞X射线照射，在另一项实验中进行分次剂量450伦琴的照射，然后在其三代后代中测量了这种照射的遗传效应。根据受照射和未受照射种群之间的窝仔数差异，对显性致死突变率的估计值——(2至3)×10⁻⁴/配子/伦琴——与先前对大鼠和小鼠的估计值一致。从品系内雄性比例得出的性连锁隐性突变率估计值——(1至2)×10⁻⁴/染色体/伦琴——也有类似的一致性；然而，在杂种中进行测量时，受照射品系中的雄性比例高于未受照射品系。结果的这种不一致与报道的小鼠隐性性连锁致死突变率的矛盾结果一致。用于估计隐性致死突变率的效应异常高——(2至14)×10⁻⁴/配子/伦琴——但并不显著。推测了其他可能导致观察到的效应的因素。
