甘蓝型油菜BAN同源基因片段克隆与序列分析

参照拟南芥（Arabidopsis thaliana)BAN基因和cDNA的保守序列设计引物，对甘蓝型、白菜型、芥菜型油菜和拟南芥及其它十字花科栽培品种的基因组总DNA进行PCR扩增，均获得与拟南芥BAN基因扩增片段大小极其相似的PCR扩增产物，表明BAN基因可能广泛存在于十字花科植物中。甘蓝型油菜和拟南芥BAN扩增片段测序比较分析显示，拟南芥BAN片段（779bp)与已往的报道完全相同，甘蓝型油菜的BAN片段（780bp)与拟南芥BAN外显子的同源性为90％，但与内含子的同源性仅为74％。甘蓝型油菜BAN氨基酸序列与80多种植物的NADPH还原酶类有不同程度的同源性。

Cloning and sequence analysis of homologous fragment of BAN from Brassica napus

Two primers, designed according to the conserved regions of BAN gene in Arabidopsis thaliana , were used to amplify the BAN homologous fragments from the genomic DNA of Brassica napus , B.campestris, B.juncea, A. thaliana and other cultural plants of Cruciferae . The very similar PCR fragments were obtained from all the amplifications, which implicated that BAN may be a conserved gene existing widely in the genomes of Cruciferae . PCR fragments were cloned and confirmed by restriction enzyme digestion. The clones inserted with BAN fragments of B.napus and A.thaliana were sequenced and compared with the sequences in genebank. The results showed that the BAN fragment of A.thaliana had the same sequence (779bp) as reported. The BAN fragment of B.napus was 780bp and its extron had 90% of homology with those of A.thaliana BAN. The sequences of intron, however, had only 74% of homology with those of A.thaliana BAN. In addition, amino acid sequence of BAN had various homologies with many NADPH-dependent reductases of other plants.