Noble N A, Brewer G J
Genetics. 1977 Apr;85(4):669-79. doi: 10.1093/genetics/85.4.669.
The erythrocyte glycolytic intermediate 2,3-diphosphoglycerate (DPG) and adenosine triphosphate (ATP) play an important role in oxygen transport and delivery by binding to hemoglobin (Hb) and reducing its affinity for oxygen. Considerable quantitative variability in the levels of DPG and ATP exists in human populations and in a population of hooded (Long-Evans) rats we have studied. This paper presents the results of studies on the genetic component of DPG-level variation in an outbred population of hooded rats. Beginning with about 100 rats, a two-way selection experiment was initiated. Pairs of rats with the highest DPG levels were mated to produce a High-DPG rat strain and animals with the lowest DPG levels were mated to produce a Low-DPG strain. Mean DPG levels responded rapidly to selection and, from generation 3 on, the differences between strain means were highly significant. Ten High-DPG strain rats were intercrossed with 10 Low-DPG strain rats of generation 10 to produce an F1 generation in which the DPG levels were almost as high as those of High-DPG animals. This indicates partial dominance of High-DPG alleles. The F2 DPG-level distribution showed two distinct subpopulations. The high DPG subpopulation contained three times as many animals as the low DPG subpopulation. From these results and the statistical analyses performed, it was concluded that the DPG differences between strains were due to an allelic difference at one major locus, the allele carried by the High-DPG strain showing partial dominance over the allele carried by the Low-DPG strain. It appears that this locus may also effect ATP levels to a large extent and is polymorphic in hooded rat populations. Identification of this locus gives us a useful tool for studies of the physiological effects of DPG variability, as well as providing an example of a major gene effect in a quantitatively varying trait.
红细胞糖酵解中间产物2,3 - 二磷酸甘油酸（DPG）和三磷酸腺苷（ATP）通过与血红蛋白（Hb）结合并降低其对氧气的亲和力，在氧气运输和传递中发挥重要作用。人类群体以及我们所研究的带帽（长 Evans）大鼠群体中，DPG和ATP水平存在相当大的数量变异性。本文介绍了对带帽大鼠远交群体中DPG水平变异的遗传成分的研究结果。从大约100只大鼠开始，启动了一项双向选择实验。将DPG水平最高的大鼠配对繁殖，产生高DPG大鼠品系，将DPG水平最低的动物配对繁殖，产生低DPG品系。平均DPG水平对选择反应迅速，从第3代开始，品系均值之间的差异非常显著。将10只第10代的高DPG品系大鼠与10只低DPG品系大鼠杂交，产生F1代，其DPG水平几乎与高DPG动物的水平一样高。这表明高DPG等位基因具有部分显性。F2代DPG水平分布显示出两个不同的亚群体。高DPG亚群体中的动物数量是低DPG亚群体的三倍。根据这些结果以及所进行的统计分析，得出结论：品系之间的DPG差异是由于一个主要位点的等位基因差异所致，高DPG品系携带的等位基因对低DPG品系携带的等位基因表现出部分显性。看来这个位点在很大程度上也可能影响ATP水平，并且在带帽大鼠群体中是多态的。鉴定这个位点为我们研究DPG变异性的生理效应提供了一个有用的工具，同时也为定量变异性状中的主基因效应提供了一个例子。
