Dystrophin基因第51内含子全序列的测序及序列特点分析  

The full sequence of intron 51 of dystrophin gene and its characteristic of sequence

作　　者：潘速跃[1] 张成[1] 刘焯霖[1] 陈国俊[1] 盛文利[1] 卢锡林[1] 

机构地区：[1]中山医科大学附属第一医院神经内科

出　　处：《中华医学遗传学杂志》2002年第1期26-29,共4页Chinese Journal of Medical Genetics

基　　金：国家自然科学基金 (39870 80 4 ;30 1 70 337) ;广东省自然科学基金 (970 0 61 ) ;卫生部临床重点项目基金 (970 4 0 2 2 9) ;美国纽约中华医学基金会基金 (98- 677)~~

摘　　要：目的　了解 dystrophin基因第 5 1内含子的序列特点。方法　用步移法测定第 5 1内含子全序列。测序结果用软件进行重复序列、基质附着区 (matrix attachment region,MAR)等分析 ,将全序列剔除重复序列后进行 Cp G岛、启动子、开放性可读框架 (open reading frame,ORF)及未鉴定的低拷贝重复序列分析。结果　第 5 1内含子由 3872 5 bp组成 ,GC含量为 36 .34 % ,重复序列占 37.5 3%。重复序列中以 L1序列含量最高 ,占整个内含子的 15 .38%。在第 5 1内含子发现有 4个 MAR和 1个 Topo 位点。在正反链上均发现有预测的 ORF,但根据预测的氨基酸序列未在蛋白质库中发现有同源蛋白。结论　在人类进化过程中部分内含子的扩增可能与 L1序列的插入有关 ;并非所有的重复序列均与染色体重排有关 ;在第 5 1内含子未发现重叠有其他基因结构 ;该内含子内密集有 4个 MAR结构 ,可能与形成缺失有关的染色质结构有关。Objective To finish the work of sequencing the full sequence of intron 51 of dystrophin gene and understand its characteristic of sequence.Methods The whole intron 51 was sequenced by primer walking. The sequencing results were analyzed by repeat sequences, matrix attachment region (MAR) and topoisomerase Ⅱ cleavage sites. The residue sequences, after removal of the repetitive sequences, were subjected to the analysis of CpG islands, promoter, open reading frame (ORF) and unidentified low copy repeat sequence.Results The acquired intron 51 sequence was composed of 38 725 bp. Repetitive sequences constituted 37.53% of total intron sequence. The overall G+C content of intron 51 was 36.34%. There are four potential MARs in intron 51. Three of them are clustered in the 12 kb region near exon 51. Numerous ORFs were found on both strands, but no homologues proteins were found in Genbank CDS transcriptional peptide, PDB, SwissProt, PIR and PRF databases. Conclusion The expansion of intron 7 over the last 120 million years was mainly the result of L1 insertion into intron 7, and not all of repetitive sequences are associated with chromosomal rearrangement. No sequence of functional significance was found in intron 51. The results suggest that the cluster of MARs may be associated with the instability of intron 51.

关 键 词：肌营养不良蛋白 内含子 肌营养不良症 缺失机理 

分 类 号：R394.3[医药卫生—医学遗传学]