EVIDENCE FOR A MAJOR GENE FOR RAPID POSTWEANING GROWTH IN MICE
EVIDENCE FOR A MAJOR GENE FOR RAPID POSTWEANING GROWTH IN MICE
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DOI：
10.1017/s0016672300026537
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发表时间：
1984-01-01
影响因子：
1.5
通讯作者：
FAMULA, TR
中科院分区：
文献类型：
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作者：
BRADFORD, GE;FAMULA, TR
在选择用于高21-42天体重增加的品系中，从第25代开始观察到小鼠增加了高于平均值3个或更多标准差。异常生长率似乎是由于一个常染色体隐性基因，基于以下：异常个体突然出现，仅在2个密切相关的亚系之一;交配高生长个体无关，正常大小的菌株产生相对均匀的F1，平均增益低于中亲平均值; F2具有明显偏向高增益的分布和近似为F1的两倍的变异系数;通过对最大的F_2进行互交，在1代内可建立真正的育种高生长株系，对正常的F_2进行互交，除了少数大分离株外，产生的后代与F_1的分布相似;与C57 BL/6自交系连续回交4次，在F_2中获得了高生长分离株。符号hg（高生长）被建议用于假定基因，该基因似乎是完全隐性的。频率的F2和回交阳性分离平均小于25和50%，可能是由于一些重叠的汞和汞汞分布。21-42日龄的hg hg个体的增重比同期的Hg-高30-50%;成熟体重也高得多，而分离窝中hg hg个体的21日龄体重略低。纯合子的生育能力范围从正常到高达40%低于可比汞-小鼠;汞汞小鼠不肥胖。该基因可能为研究哺乳动物的生长调控提供一个有用的模型。
Mice gaining 3 or more standard deviations above the mean were noted beginning in generation 25 in a line selected for high 21-42 day weight gain. The exceptional growth rate appears to be due to an autosomal recessive gene, based on the following: the exceptional individuals appeared suddenly, in only one of 2 closely related sublines; mating high growth individuals to unrelated, normal size strains produces relatively uniform F1 with mean gains below the mid-parent average; F2 have a distribution markedly skewed towards high gain and a coefficient of variation approximately double that of F1; true breeding high growth strains can be established in 1 generation by intermating the largest F2; intermating normal F2 produces progenies with a distribution similar to the F1 except for a few large segregates; high growth segregates were obtained in F2 from each of 4 successive backcrosses to the C57BL/6 inbred line. The symbol hg (high growth) is proposed for the postulated gene, which appears to be completely recessive. Frequency of positively identified segregates in F2 and backcrosses is on average less than 25 and 50%, due probably to some overlap of Hg- and hg hg distributions. Gain of hg hg individuals from 21-42 days is 30-50% higher than of Hg- contemporaries; mature weight is also much higher, while 21-day weight of hg hg individuals in segregating litters is slightly lower. Fertility of homozygotes ranges from normal to as much as 40% lower than for comparable Hg- mice; hg hg mice are not obese. The gene may provide a useful model for study of regulation of mammalian growth.