中文摘要：

通过比对拟南芥等同源基因，克隆了甘蓝型油菜FAD8基因中的保守序列．以得到的FAD8（Fatty Acid Desaturase 8）保守序列片段为信息探针，在GenBank的EST数据库中检索高度同源的EST，并通过人工拼接及RT—PCR得到油菜该基因的全长为1299bp的cDNA序列，命名为BnFAD8．序列分析结果中发现该基因符合质体定位的∞3脂肪酸脱饱和酶序列特征．通过比较22℃和8℃处理的甘蓝型油菜的BnFAD8基因表达谱，发现该基因在常温下仅存在痕量表达；而在低温条件下在叶中表达出现较大幅度的升高．推测BnFAD8基因和油菜的低温调控存在联系．

英文摘要：

Brassica napus fatty acid desaturase 8 （FADS） belongs to cold-induced omega 3 fatty acid desaturase. By aligning Arabidopsis FAD8 and other homologous FAD8 genes, one highly conserved sequence of FAD8 from rape was cloned in study. Using the FAD8 conserved sequence as a querying probe, highly homologous EST were obtained from database of GenBank and a putative complete ORF of 1299 bp （named. BnFAD8） was assembled according to the rape clone. Furthermore, the full length cDNA of Brassica napus FAD8 was cloned by RT-PCR with two primers designed based on this assembled cDNA sequence. Features of plasmid-located 0o3 fatty acid desaturase were found in sequence analy- sis of cDNA cloned. As shown in expression profile result, BnFAD8 was highly expressed in leaves at 8 ℃, but only trace-level expression in leaves at 22 ℃, which suggested that BnFAD8 involved in the process of rape cold acclimation.