果蝇三倍体的剂量补偿。二、葡萄糖-6-磷酸脱氢酶活性。
Dosage Compensation in DROSOPHILA MELANOGASTER Triploids. II. Glucose-6-Phosphate Dehydrogenase Activity.
机构信息
Department of Zoology, University of Wisconsin, Madison, Wisconsin 53706.
出版信息
Genetics. 1973 Jun;74(2):331-42. doi: 10.1093/genetics/74.2.331.
The level of activity of the enzyme glucose-6-phosphate dehydrogenase was determinel in flies having seven different chromosomic constitutions. All those having an integral number of chromosomes [XAA, XXAA, XAAA, XXAAA, and XXXAAA (X=Xchromosome, A=set of autosomes)] were found to have similar units of enzyme activity/mg live weight, while diploid females with a duplication and triploid females with a deficiency showed dosage effect. The amount of enzyme activity per cell, on the other hand, is also independent of the number of X's present but appears roughly proportional to the number of sets of autosomes.-It is proposed that dosage-compensated sex-linked genes are controlled by a positively acting regulatory factor(s) of autosomal origin. With this hypothesis it is possible to explain dosage compensation as a consequence of general regulatory mechanisms without invoking a special device which applies only to the X chromosomes.
测定了具有七种不同染色体组成的果蝇中葡萄糖-6-磷酸脱氢酶的活性水平。所有具有整数染色体数[XAA、XXAA、XAAA、XXAAA 和 XXXAAA（X=X 染色体，A=常染色体组）]的果蝇被发现具有相似的单位酶活/毫克活重，而具有重复的二倍体雌性果蝇和具有缺失的三倍体雌性果蝇则表现出剂量效应。另一方面，每个细胞的酶活性量也与存在的 X 染色体数量无关，但似乎与常染色体组数大致成比例。-提出了一种假设，即剂量补偿性连锁基因受来自常染色体的正调控因子的控制。根据这个假设，可以将剂量补偿解释为一般调控机制的结果，而无需引入仅适用于 X 染色体的特殊装置。
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