AUTOSOMAL DOSAGE COMPENSATION IN DROSOPHILA-MELANOGASTER STRAINS TRISOMIC FOR THE LEFT ARM OF CHROMOSOME-2
AUTOSOMAL DOSAGE COMPENSATION IN DROSOPHILA-MELANOGASTER STRAINS TRISOMIC FOR THE LEFT ARM OF CHROMOSOME-2
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DOI：
10.1073/pnas.79.4.1200
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发表时间：
1982-01-01
期刊：
影响因子：
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通讯作者：
GRIGLIATTI, TA
中科院分区：
文献类型：
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作者：
DEVLIN, RH;HOLM, DG;GRIGLIATTI, TA
整个染色体臂三体的黑腹蝇个体可以存活到蛹发育的后期。5种酶[磷酸甘油酸激酶，α。对位于2号染色体左臂的-甘油-3-磷酸脱氢酶、细胞质苹果酸脱氢酶、酒精脱氢酶和多巴脱羧酶等结构基因在2L三体和二倍体菌株中进行了检测。在三体中，3个远端定位位点显示出与二倍体菌株接近的补偿表达水平。对一个补偿位点的电泳变异分析表明，所有3个等位基因在三体中都是活跃的。2个位于近端的基因座表现出剂量依赖性的表达水平。在单个基因的水平上，常染色体补偿似乎是一种全有或全无的现象。代偿反应可能沿染色体臂区域分布。常染色体和性别连锁剂量补偿的存在促使我们推测，这些现象是调节整倍体和非整倍体基因组中基因表达的类似稳态机制。
D. melanogaster individuals trisomic for an entire chromosome arm can survive to late stages of pupal development. The levels of 5 enzymes [phosphoglycerate kinase, .alpha.-glycerol-3-phosphate dehydrogenase, cytoplasmic malate dehydrogenase, alcohol dehydrogenase and dopa decarboxylase], the structural genes of which are located on the left arm of chromosome 2, were examined both in trisomy 2L and in diploid strains. In trisomies, 3 distally mapping loci showed compensated levels of expression close to that observed in the diploid strains. Analysis of electrophoretic variants of a compensated locus revealed that all 3 alleles are active in trisomies. The 2 proximally located loci displayed dose-dependent levels of expression. At the level of the individual gene, autosomal compensation appears to be an all-or-none phenomenon. The compensatory response may be regionally distributed along the chromosome arm. The presence of both autosomal and sex-linked dosage compensation prompts us to speculate that these phenomenon are similar homeostatic mechanisms that modulate gene expression both in euploid and aneuploid genomes.