Gianola D, Chapman A B, Rutledge J J
Genetics. 1977 Aug;86(4):861-83. doi: 10.1093/genetics/86.4.861.
Effects of nine generations of 450r per generation of ancestral spermatogonial X irradiation of inbred rats on genetic parameters of body weight at 3, 6, and 10 weeks of age and of weight gains between these periods were studied. Covariances among relatives were estimated by mixed model and regression techniques in randomly selected lines with (R) and without (C) radiation history. Analyses of the data were based on five linear genetic models combining additive direct, additive indirect (maternal), dominance and environmental effects. Parameters in these models were estimated by generalized least-squares. A model including direct and indirect genetic effects fit more closely to the data in both R and C lines. Overdominance of induced mutations did not seem to be present. Ancestral irradiation increased maternal additive genetic variances of body weights and gains but not direct genetic variances. Theoretically, due to a negative direct-maternal genetic correlation, within full-sib family selection would be ineffective in increasing body weight at six weeks in both R and C lines. However, progress from mass selection would be expected to be faster in the R lines.
研究了近交系大鼠亲代精原细胞每代450伦琴、共九代的X射线照射对3周、6周和10周龄体重的遗传参数以及这些时期之间体重增加的影响。通过混合模型和回归技术，对具有（R）和不具有（C）辐射史的随机选择品系中的亲属间协方差进行了估计。数据的分析基于五个线性遗传模型，这些模型结合了加性直接效应、加性间接（母体）效应、显性效应和环境效应。这些模型中的参数通过广义最小二乘法进行估计。一个包含直接和间接遗传效应的模型在R系和C系中都更符合数据。诱导突变的超显性似乎不存在。亲代照射增加了体重和体重增加的母体加性遗传方差，但没有增加直接遗传方差。从理论上讲，由于直接与母体遗传呈负相关，在全同胞家系内选择在增加R系和C系六周龄体重方面将是无效的。然而，预计在R系中，群体选择的进展会更快。
