中文摘要：

采用基因组步移和RACE（rapid amplification of cDNA ends）技术,从甘蓝型油菜中双9号中克隆到了KCS6基因。甘蓝型油菜中KCS6基因有两个拷贝：BnKCS6c（与甘蓝的mRNA 99%同源）和BnKCS6a（与白菜的mRNA 99%同源）。这两个拷贝的编码区长度均为1 494bp,含有2个外显子,一个长1 045bp,另一个449bp。种子发育初期KCS6基因在角果皮和种子中表达量高,随着种子成熟表达量迅速降低。两个KCS6的转基因都可以在酵母中正常表达,但不能合成超长链脂肪酸,表明酵母中异源表达的KCS6蛋白没有活性,或KCS6蛋白不能以酵母的脂肪酸作为催化底物合成超长链脂肪酸。

英文摘要：

GenomeWalking together with RACE techniques were used to clone KCS6 genes from B.napus cv.Zhongshuang 9.Two copies of KCS6 gene were found in B.napus,depending on their ancestral origin.One was BnKCS6c,showing 99% identity to corresponding B.oleracea mRNA.The other was BnKCS6a showing 99% identity to corresponding B.rapa mRNA.Both genes had a 1 494bp-coding region composed by 2 exons spanning 1 045bp and 449bp respectively.In early stage of seed development,KCS6 expression level was high in silique shell and seeds,but rapidly reduced when seeds matured.Both transgenic KCS6 genes could be normally translated into proteins in yeast cells,but no synthesis of very long chain fatty acids was observed.It indicated that the heterologous expressed KCS6 protein has no catalytic activity,or KCS6 protein is not able to utilize the yeast fatty acid as catalytic substrate to synthesize very long chain fatty acid.