国兰肌动蛋白基因片段的克隆与表达分析

Cloning and Expression Analysis of Actin Fragment from Cymbidium

摘要:

根据兰科植物(Orchidaceae)蝴蝶兰(Phalaenopsis)的肌动蛋白基因(Actin)序列设计跨内含子引物，分别以cDNA第一链和基因组DNA为模板，采用RT-PCR和PCR方法从墨兰(Cymbidium sinense)、春兰(C. goeringii)中分离出Actin基因的同源片段。序列分析结果表明：墨兰和春兰Actin基因片段长度均为1335 bp，其中编码区长度均为1086 bp，编码362个氨基酸，分别命名为CsACT1和CgACT1(GenBank登录号分别为GU181353、GU181354)。CsACT1和CgACT1均含有3个内含子，且内含子位置非常保守。其氨基酸序列与其他植物的同源性均在90%以上，具有高度的保守性。CsACT1和CgACT1在根、茎、叶、花梗、花蕾以及花器官中都有表达，且表达量基本一致，因此，推断其为组成型表达的肌动蛋白基因。

Abstract:

Cross-intron primers were designed according to the nucleotide sequence of the Actin of Phalaenopsis, and Actin homology fragments from Cymbidium sinense and C. goeringii were obtained by reverse transcription polymerase chain reaction (RT-PCR) and PCR using the first chain of cDNA and the genomic DNA as templates. The results showed that the Actin franments from C. sinense and C. goeringii were 1335 bp in length with 1086 bp coding sequences, encoding a protein of 362 amino acids. They were named as CsACT1 and CgACT1 (GenBank accession number were GU181354 and GU181353), respectively. Both of CsACT1 and CgACT1 consisted of three conservative introns. The amino acid sequence shared over 90% to those of other plants in the GenBank, so that the Actin genes from Cymbidium were highly conservative. The CsACT1 and CgACT1 could express at similar level in root, stem, leaf, pedicel, bud and floral organ, so that CsACT1 and CgACT1 might be constitutive expression Actin genes.