Schwartz P E, Doane W W
Department of Zoology, Arizona State University, Tempe 85287-1501.
Biochem Genet. 1989 Feb;27(1-2):31-46. doi: 10.1007/BF00563016.
Overlapping clones of the structural gene region for alpha-amylase, Amy, were isolated from a lambda EMBL4 library containing genomic DNA fragments from an amylase-null strain of Drosophila melanogaster. Southern blot analysis and restriction endonuclease mapping of the cloned region indicate that it contains an Amy gene duplication within an inverted repeat sequence as is characteristic of the genomic arrangement for this species. Spacing between the cloned gene copies is similar to that commonly found in other strains. Evidence is presented for the presence of an inversion 4 to 9 kb in length within the cloned Amy region of the null strain. We postulate a causal relationship between the presence of the inversion and the failure of individuals from the null strain to express amylase. A model is proposed that suggests the inversion may have arisen through intramolecular (or sister-strand) recombination mediated by homologous pairing of the inverted repeat sequences at the Amy locus.
从一个λEMBL4文库中分离出了α淀粉酶（Amy）结构基因区域的重叠克隆，该文库包含来自黑腹果蝇淀粉酶缺失菌株的基因组DNA片段。对克隆区域的Southern印迹分析和限制性内切酶图谱分析表明，它在一个反向重复序列内包含一个Amy基因重复，这是该物种基因组排列的特征。克隆基因拷贝之间的间距与其他菌株中常见的间距相似。有证据表明，在缺失菌株的克隆Amy区域内存在一个长度为4至9 kb的倒位。我们推测倒位的存在与缺失菌株个体无法表达淀粉酶之间存在因果关系。提出了一个模型，表明倒位可能是由Amy基因座处反向重复序列的同源配对介导的分子内（或姐妹链）重组产生的。
