Zerges W, Udvardy A, Schedl P
Department of Biology, Princeton University, NJ 08544.
Nucleic Acids Res. 1992 Sep 11;20(17):4639-47. doi: 10.1093/nar/20.17.4639.
A detailed analysis of the 5' end of the rudimentary gene of Drosophila melanogaster is presented. Rudimentary transcripts are heterogeneous at their 5' ends indicating that transcription is initiated at multiple sites within a region of approximately 50 bp. These transcription initiation sites are within a region that is preferentially susceptible to nuclease cleavage in isolated nuclei. Additional nuclease hypersensitive regions were found within the first exon and the first intron. Within these internal nuclease hypersensitive regions are the insertion sites for previously identified P element transposons which disrupt rudimentary expression. One of these P element insertions, located in the first intron, is removed from the rudimentary transcript with the splicing of this intron. Another P element insertion, within the first exon, is removed from the rudimentary transcript by novel first intron splicing involving a cryptic splice donor site, located 5' to the insertion, and either the normal acceptor site or a cryptic splice acceptor site within the second exon.
本文对黑腹果蝇残翅基因的5'端进行了详细分析。残翅转录本在其5'端具有异质性，这表明转录是在大约50 bp区域内的多个位点起始的。这些转录起始位点位于一个在分离的细胞核中对核酸酶切割敏感的区域内。在第一个外显子和第一个内含子内还发现了其他核酸酶超敏区域。在这些内部核酸酶超敏区域内是先前鉴定的P因子转座子的插入位点，这些转座子会破坏残翅基因的表达。其中一个位于第一个内含子中的P因子插入，在该内含子剪接时从残翅转录本中去除。另一个位于第一个外显子内的P因子插入，通过涉及一个位于插入位点5'端的隐蔽剪接供体位点以及第二个外显子内的正常接受位点或隐蔽剪接受体位点的新型第一个内含子剪接，从残翅转录本中去除。
