中文摘要：

本研究采用兼并PCR（polymerase chain reaction）和DRACE（rapid amplification of cDNA ends）技术分离了绵刺 （Potaninia mongolica Maxim.）肌动蛋白基因（A ctin, PmA ctin）cDNA序列，该序列包含有1134bp的开放阅读框（openreading frame，ORF），编码377个氨基酸，预测蛋白分子量为41．8kD，理论等电点为5．48；基因组DNA序列长度为1134bp，无内含子。该序列与其他植物Actin的一致性较高，核苷酸均高于88％，氨基酸则均高于96％。系统进化分析显示：PmActin与同属蔷薇科的草莓、碧桃，扁桃和蔷薇及葡萄科的葡萄Actin蛋白聚为一个亚类，与草莓Actin蛋白亲缘关系最为接近。RT-PCR分析显示，该基因在根、茎、叶中的表达量无明显变化，该结果验证了PmActin基因可作为分子内标的可靠性，为深入开展该植物的分子生物学研究提供理论依据。

英文摘要：

Actin （PmA ctin） cDNA sequence was isolated from Potaninia rnongolica Maxim by using polymerase chain reaction （PCR） combined with rapid amplification of cDNA ends （RACE） techniques. This sequence contained an open reading frame （ORF） of 1 134 bp, and encoded 377 amino acids. The predicted protein molecular weight was 41.8 kD and the theoretical isoelectric point was 5.48. The length of genomic DNA sequence was 1134 bp, with no intron. Homologous alignment showed that it shared over 88% of nucleotide identities and 96% of amino acid identities with Aactin from other plants in Genbank. Phylogenetic analysis showed that the PmActin was in the same subvariety with the Actin proteins from rosaeeae and vitaceae, including Arbutus rnenziesii, Prunus persica, Prunus dulcis, Rosa rnultiflora, and Vitis vinifera. And it showed the closest relationship with Actin proteins of Arbutus menziesii. Fragaria x ananassa and Fragaria vesca subsp, vesco. RT-PCR revealed that the expression of the PmActin gene had no obvious change in root, stem or leaf. The results confirmed that the lamA ctin gene could be used as internal standard with reliability and provided theory basis for further molecular biology study of the plant.