摘要根据GenBank中登录的植物肌动蛋白保守序列设计1对引物,对三叶青的块根进行RT-PCR,在1次扩增中得到两个不同的肌动蛋白基因片段,分别命名为ThAct1和ThAct2。测序结果显示ThAct1基因片段长度为867 bp,编码252个氨基酸;ThAct2基因片段长度为1079 bp,编码152个氨基酸。经Blast分析,ThAct1和ThAct2 基因均属于NBD_sugar-kinase_HSP70_actin superfamily家族,具有高度的保守性,两个肌动蛋白基因片段与其它物种Actin基因核苷酸和编码的蛋白质均具有同源性。RT-PCR结果显示,ThAct1和ThAct2基因在茎、普通根和块根中的表达未见差异;而与叶相比,茎、普通根和块根中ThAct1的表达稍强,ThAct2的表达稍弱。另外,在茎、普通根和块根中,ThAct1表达比ThAct2强;但在叶中ThAct1表达比ThAct2弱。研究结果为分析肌动蛋白基因在三叶青块根发育中的功能奠定了基础;获得的肌动蛋白也可以作为内参基因,在三叶青功能基因组的研究中用于其它基因的定量表达分析。44245
Abstract According to the conserved sequence of plant actin genes in GenBank database, one pairs of primers were designed. Two different actin gene fragments, named as ThAct1 and ThAct2, was amplified in one RT-PCR reaction from calabash-shaped root of Tetrastigma hemsleyanum Diels et Gilg. Sequencing indicated that the length of ThAct1 is 867 bp encoding 252 amino acids and the length of ThAct2 is 1079 bp encoding152 amino acids. By Blast analysis, both of ThAct1 and ThAct2 genes belong to the NBD_sugar-kinase_HSP70_actin superfamily, which are highly conserved, and two actin gene fragments and encoded protein are homology with other species. The RT-PCR analysis showed that the expression of ThAct1 and ThAct2 was no difference in the stem, ordinary root and calabash-shaped root, while compared to leaf, ThAct1 in the stem, ordinary root and calabash-shaped root was slightly high and ThAct1 was weak. Besides, the expression of ThAct1 in the stem, and ordinary root and calabash-shaped root was stronger than that of ThAct2. However, ThAct1 expression in the leaves is weaker than ThAct2. The results lay a foundation for functional analysis of actin gene in calabash-shaped root development, and the actin genes can be used as a reference gene for the analysis of other genes in the genome of Tetrastigma hemsleyanum Diels et Gilg.
毕业论文关键词:三叶青; 肌动蛋白基因; 克隆; 表达
Key words: Tetrastigma hemsleyanum Diels et Gilg; actin gene; clone; gene expression
目 录
引言 5
1 材料与方法 5
1.1 材料 5
1.2 方法 6
1.2.1 RNA的提取 6
1.2.2 cDNA第1链的合成 6
1.2.3 PCR扩增 6
1.2.4 目的片段的克隆和测序 7
1.2.5 扩展蛋白基因序列的生物信息学分析 7
1.2.6 肌动蛋白基因的表达分析 7
2 结果与分析 7
2.1 PCR扩增 7
2.2 PCR产物的克隆和鉴定 8
2.3 测序结果及序列分析 9
2.4 不同器官的表达分析 12
3 讨论 12
引言
肌动蛋白(Actin)普遍存在于真核生物的细胞中,是细胞骨架微丝的组成成分,参与细胞内很多重要的生理活动,如细胞形状的维持论文网、细胞运动、细胞内物质运输、细胞分裂等[1, 2]。单体肌动蛋白为球蛋白,一般由375-377个氨基酸残基组成[3]。阎隆飞等1963年首次报道高等植物中存在肌动蛋白[4]。在植物基因表达调控研究中,肌动蛋白基因作为一种管家基因常被广泛用作分子内标[5]。相关研究表明,高等植物肌动蛋白由多基因编码,目前,百合[6]、茶树[7]、刺五加[8]、马铃薯[9]等植物的肌动蛋白基因已被克隆和分析,但有关珍稀药用植物三叶青肌动蛋白基因的研究尚未见报道。