Organization of the rosy locus in Drosophila melanogaster: further evidence in support of a cis-acting control element adjacent to the xanthine dehydrogenase structural element.
Organization of the rosy locus in Drosophila melanogaster: further evidence in support of a cis-acting control element adjacent to the xanthine dehydrogenase structural element.
复制标题
果蝇玫瑰色基因座的组织：支持与黄嘌呤脱氢酶结构元件相邻的顺式作用控制元件的进一步证据。
作者：
M. McCarron;J. O'donnell;A. Chovnick;B. S. Bhullar;J. Hewitt;E. Candido
本文总结了我们在高等生物的一个基本遗传单位--果蝇rosy基因座（ry：3- 52.0）的遗传解剖方面的最新进展。追求的假设，玫瑰色位点包括一个非编码控制区，以及编码的黄嘌呤脱氢酶（XDH）肽的结构元件，实验描述的特征和映射玫瑰色位点的变体与远低于正常水平的XDH活动。描述的实验未能将这种表型与XDH肽结构的改变联系起来，但清楚地将这种特征与每只果蝇的XDH分子数量的变化联系起来。大规模的精细结构重组实验将这种变异的遗传基础定位在每只果蝇的XDH分子数量上，即XDH结构元件左侧的一个位点，该位点位于先前指定为XDH控制元件的区域内。此外，实验清楚地将该“生产不足”变体位点与先前描述的控制区域内的“生产过剩”位点分开。适当的杂合基因型的电泳凝胶中的酶活性的检查证明了XDH分子数量的这种变化的顺式作用性质。玫瑰色轨迹，结构和控制元件的地图的修订，提出了在现在可用的额外的映射数据的光。
The present report summarizes our recent progress in the genetic dissection of an elementary genetic unit in a higher organism, the rosy locus (ry:3--52.0) in Drosophila melanogaster. Pursuing the hypothesis that the rosy locus includes a noncoding control region, as well as a structural element coding for the xanthine dehydrogenase (XDH) peptide, experiments are described that characterize and map a rosy locus variant associated with much lower than normal levels of XDH activity. Experiments are described that fail to relate this phenotype to alteration in the structure of the XDH peptide, but clearly associate this character with variation in number of molecules of XDH per fly. Large-scale fine-structure recombination experiments locate the genetic basis for this variation in the number of molecules of XDH per fly to a site immediately to the left of the XDH structural element within a region previously designated as the XDH control element. Moreover, experiments clearly separate this "underproducer" variant site from a previously described "overproducer" site within the control region. Examination of enzyme activity in electrophoretic gels of appropriate heterozygous genotypes demonstrates the cis-acting nature of this variation in the number of molecules of XDH. A revision of the map of the rosy locus, structural and control elements is presented in the light of the additional mapping data now available.