Ryseck R P, Walldorf U, Hovemann B
Chromosoma. 1985;93(1):17-20. doi: 10.1007/BF01259440.
The heat-shock locus 93D from Drosophila melanogaster has recently become available for a molecular analysis. We established a restriction site map of a recombinant DNA clone covering the major part of heat-shock locus 93D. This clone includes part of a repetitive Taq I region and neighbouring unique sequences. The portion of the Taq I repeat analysed consists of tandemly arranged sequence blocks of about 280 base pairs (bp) in length. Using genomic and cDNA as hybridization probes we examined the transcription of 93D in 2- to 4-day-old flies. We identified two major RNA classes enhanced after heat shock, namely nonpolyadenylated transcripts of heterogeneous length derived from the repetitive region and one discrete polyadenylated transcript in spliced and unspliced form from the neighbouring unique region. The occurrence of a highly heterogeneous poly(A)- transcript and high levels of an unspliced discrete poly(A)+ species suggests unusual mechanisms of transcription regulation in the 93D region.
来自黑腹果蝇的热休克基因座93D最近已可用于分子分析。我们建立了一个重组DNA克隆的限制性酶切位点图谱，该克隆覆盖了热休克基因座93D的主要部分。这个克隆包括一部分重复的Taq I区域和相邻的独特序列。所分析的Taq I重复序列部分由长度约为280个碱基对（bp）的串联排列序列块组成。使用基因组DNA和cDNA作为杂交探针，我们检测了2至4日龄果蝇中93D的转录情况。我们鉴定出热休克后增强的两类主要RNA，即来自重复区域的长度各异的非聚腺苷酸化转录本，以及来自相邻独特区域的一种经剪接和未剪接形式的离散聚腺苷酸化转录本。高度异质的聚（A）-转录本的出现以及未剪接的离散聚（A）+物种的高水平表明93D区域存在异常的转录调控机制。
