中文摘要：

保幼激素（JH）是昆虫生长、发育、变态和生殖等一系列生理生化过程中必不可少的一类激素。法尼酸甲基转移酶（farnesoic acid O-methyltransferase,FAMeT）被认为是昆虫及其它节肢动物催化合成保幼激素前体甲基法尼酸（methyl farne-soate,MF）的关键酶。通过生物信息学分析,从家蚕全基因组数据中共鉴定了7个编码家蚕FAMeT的基因（BmFAMeT1～BmFAMeT7）。系统进化分析暗示BmFAMeT2可能是家蚕FAMeT家族成员的最原始拷贝。对其中位于6号染色体上的BmFAMeT5、BmFAMeT6和BmFAMeT7的时空表达谱分析显示,3个基因从家蚕胚胎发育后期至成虫期持续性表达;在5龄第3天幼虫中肠组织特异性高水平表达。利用RACE技术克隆获得了这3个基因的全长cDNA序列,并发现BmFAMeT5及BmFAMeT6分别存在2种不同的选择性拼接形式。上述结果为进一步研究家蚕FAMeT的生物学功能提供了线索。

英文摘要：

Juvenile hormone（JH） plays important roles in various insect physiological and biochemical processes such as growth,development,metamorphosis,and reproduction.Farnesoic acid O-methyltransferase（FAMeT） is a key enzyme which is responsible for catalyzing the biosynthesis of methyl farnesoate（MF） as JH precursor in insects and other arthropods.Through bioinformatics analysis,we identified 7 genes（BmFAMeT1 to BmFAMeT 7） encoding FAMeTs from the silkworm（Bombyx mori） whole genome sequence data.Phylogenetic analysis implies that BmFAMeT 2 may be the most primitive copy of other silkworm FAMeT family members.Temporal and spatial expression pattern analysis to BmFAMeT 5,BmFAMeT 6 and BmFAMeT 7 which are located on the 6th chromosome of silkworm showed that these three genes were continuously expressed from the late embryogenesis stage to adult stage of silkworm,and were highly expressed specifically in midgut tissue of day 3 larvae of the 5th instar.Furthermore,we cloned the full-length cDNA sequences of these three genes using RACE technology and found that BmFAMeT 5 and BmFAMeT 6 have two alternative splicing isoforms respectively.These results provide clues for further investigation on biological functions of silkworm FAMeTs.