小麦UROS基因的可变剪接  

Alternative Splicing of Uroporphyrinogen Ⅲ Synthase Genes in Wheat

作　　者：郎丹莹 吕庚寅 梁广旺[1] 李瑞航[1] 郭晓光[1] 徐虹[1,2] 郭蔼光[1,2] 

机构地区：[1]西北农林科技大学生命科学学院,陕西杨凌712100 [2]旱区作物逆境生物学研究国家重点实验室,陕西杨凌712100

出　　处：《麦类作物学报》2016年第12期1553-1562,共10页Journal of Triticeae Crops

基　　金：国家自然科学基金项目(30971769;31371541)

摘　　要：可变剪接是一种重要的基因表达调控机制,对植物的发育、生理、代谢、信号转导以及外界逆境的响应等多个过程都有调控。为进一步探讨小麦基因的可变剪接机制以及深入研究小麦UROS基因的功能,以返白系、矮变1号和中国春三个普通六倍体小麦品种为材料,克隆了尿卟啉原Ⅲ合成酶基因(UROS)的gDNA和cDNA序列,并利用生物信息学技术研究了小麦叶片中UROS基因的可变剪接方式。结果表明,根据在线小麦基因组数据库,将克隆到的UROS基因组DNA序列分别定位在4BL和4DL两个基因位点,命名为UROS-4B和UROS-4D。从三个品种中克隆得到大约50个不同的UROS基因cDNA序列,通过在线预测和与基因组序列比对,发现UROS基因存在可变剪接,并鉴定出两个UROS基因位点各有一个标准剪接转录本和两个非标准剪接转录本。可变剪接方式以内含子保留为主,还有可变的供体剪接位点和可变的受体剪接位点,品种间的剪接方式不完全相同。由不同转录本预测编码的多肽氨基酸序列也存在差异,两个基因位点选取的六个转录本所编码的多肽有12个氨基酸位点的变异。Alternative splicing （AS） is a key regulatory mechanism of gene expression,which is related to the development, physiology, metabolism, signal transduction and stress-response of plant. In this experiment,we cloned the Uroporphyrinogen Ⅲ synthase（UROS） genes from gDNA and cDNA of wheat and investigated the AS of UROS genes in wheat with bioinformatics techniques, using Albinism line,Aibian 1 and Chinese Spring as materials. The UROS gDNA sequences are located on 4BL and 4DL chromosomes based on the wheat genome sequences online database, which are designated as UROS-4B and UROS-4D,respectively. About 50 different UROS cDNA sequences were cloned and se- quenced from three cultivars. We found the AS in UROS pre-mRNA processing through the online predication and the comparison between eDNA and gDNA sequences,and there are one canonical and two non-canonical transcripts of each gene location. Intron retention is the primary alternative splicing type,as well as alternative donor introns and alternative receptor introns were found,and different varieties showed diverse splicing types.In addition, the predicated amino acid sequence of these tran-scripts were dissimilar,twelve variant amino acid sites were identified from six polypeptides encoded by six clones from different transcripts, respectively.

关 键 词：小麦 返白系 尿卟啉原Ⅲ合成酶 可变剪接 标准剪接与非标准剪接 

分 类 号：S512.1[农业科学—作物学] S330