基因新异构体的剪接特征及其生物学意义

目的 探讨基因新异构体的剪接特征及生物学意义。方法 对人肾上腺组织cDNA文库作大规模DST分析及全长cDNA克隆。结果 发现7条由不同剪接方式形成的新的异构体，其中4个剪接特点不符合经典的gt-ag规律，且剪接方式多样，人类固醇5α还原酶跨越两个外显子，KIAA0971的异构体与KIAA0971比较，有两段缺失，且造成编码框架移动，均按gt-at方式。人17．9kd蛋白与从基因组序列预测的cDNA比较增加一个新外显子，人甲状腺素受体相互作用蛋白15的第5号外显子端具有2个－ag的接点。结论 表明体内mRNA成熟过程中剪接方式呈现多样性及复杂性。

The Splicing Characteristics and Biological Significance of New Isoforms in NovelFull - Length cDNA Cloning

Objective To explore the splicing patterns and biological significance of new isoforms in full-length cDNA cloning. Methods Large_scale analysis of expressed sequence tags (ESTs) from human adrenal cDNA and full-length cDNA cloning were carried out. Results Seven isoforms by different splicing patterns were identified. Four of them did not follow the typical gt_ag pattern. In human steroid 5_alpha_reductase splicing spanned 2 exons. Two sections of deletion were found in the new isoform of KIAA0971 by the gt-ag splicing pattern and ORF was shifted. Comparing with the genomic sequence, a new exon was increased in human 17.9kd protein (a new isoform), and there were two-ag adaptors in the 3' end of exon5 of the human thyroid receptor interactor 15. Conclusion It is suggested that the splicing patterns are diverse and complex in the processing of mRNA in human beings.