Gray J E, Larsen E R, Greenberg H S
Lab Anim Sci. 1982 Dec;32(6):609-12.
Breeder male Sprague-Dawley rats were categorized as potential low and high protein excretors at 4 months of age. The average selection values of these two groups were 0.59 and 1.75 mg/ml, respectively. Paris of females were mated to these males in two breeding cycles in the fashion of a diallele cross. The heritability index based on protein excretion values of 263 male offspring at 6 months of age from both cycles of high and low excretor males was 0.526 with approximate variance of 0.0668. Significantly different (p less than 0.01) survival distributions were shown. The mean and median survival times of the high excretor offspring were 611.1 and 652 days, respectively, compared to 651.4 and 680.5 days, respectively, in low excretor offspring. The proportion of offspring with marked chronic progressive nephrosis was significantly greater (p less than 0.01) in the high excretor group, both prior to and after 700 days of age, than that of offspring in the low excretor group. The selection of low excretor males for breeding stock appears to offer a practical basis for minimizing the total expression of chronic progressive nephrosis in this strain of rat.
繁殖用雄性斯普拉格-道利大鼠在4月龄时被分为潜在的低蛋白排泄者和高蛋白排泄者。这两组的平均选择值分别为0.59和1.75毫克/毫升。将雌性大鼠与这些雄性大鼠进行两个繁殖周期的交配，采用双列杂交的方式。基于来自高排泄者和低排泄者雄性大鼠两个繁殖周期的263只6月龄雄性后代蛋白质排泄值的遗传力指数为0.526，近似方差为0.0668。显示出显著不同（p<0.01）的生存分布。高排泄者后代的平均和中位生存时间分别为611.1天和652天，而低排泄者后代分别为651.4天和680.5天。在700日龄之前和之后，高排泄者组中患有明显慢性进行性肾病的后代比例均显著高于（p<0.01）低排泄者组的后代。选择低排泄者雄性作为种畜似乎为使该品系大鼠慢性进行性肾病的总表达最小化提供了一个实际依据。
