Different chromatin states of the intron- and type 1 intron+ rRNA genes of Calliphora erythrocephala.
Different chromatin states of the intron- and type 1 intron+ rRNA genes of Calliphora erythrocephala.
复制标题
红头丽丽的内含子和 1 型内含子 rRNA 基因的不同染色质状态。
DOI：
10.1007/bf00287040
复制
发表时间：
1984
期刊：
影响因子：
1.6
通讯作者：
Rubacha,A
中科院分区：
文献类型：
--
作者：
Beckingham,K;Rubacha,A
In most species of dipteran fly examined, a fraction of the rDNA cistrons are interrupted by introns. These dipteran intron+rRNA genes are unique in that they are transcriptionally inactive. Previous studies have investigated the mechanism underlying this transcriptional repression for rRNA genes carrying the best characterized sequence family of such introns, the so-called type 1 introns first identified inDrosophila melanogaster. These studies have established that cloned examples of both intron-free and type 1 intron+rRNA genes will support transcription in a cell-free system and suggest therefore that a difference in the chromatin state of the two gene types must underlie their very different potential for in vivo transcription. We have examined this possibility for the type 1 intron+rDNA cistrons ofCalliphora erythrocephalaby in situ hybridization studies using the polytene chromosome complement of the pupal bristle-forming (trichogen) cells. These studies show that the chromatin configuration of the two gene types is strikingly different. The intron-free genes are preferentially localized in the actively transcribed fibrillar center of the nucleolus. The intron+genes are preferentially condensed in the blocks of heterochromatin attached to the nucleolus.
