家蚕Atlastin基因(BmATL)的鉴定及表达模式

Identification and Expression Patterns of Atlastin Genes in Silkworm,Bombyx mori

Atlastin基因是人类遗传性痉挛性截瘫(hereditary spastic paraplegia,HSP)疾病的致病基因之一。Atlastin蛋白具有典型的GTP结合(GBP)结构域和2个相邻的跨膜结构,被定位在高尔基体和内质网膜上,具有运输小囊泡的功能。用人类和果蝇的Atlastin基因序列对家蚕基因组数据库进行同源搜索,鉴定得到4个同源基因,命名为BmATL1-BmATL4。生物信息学分析显示这4个基因编码的蛋白质都有GBP结构域,其中:BmATL1和BmATL2的分子质量约60 kD,有2个相邻的跨膜结构;BmATL3和BmATL4的分子质量约85 kD,没有跨膜结构。表达谱分析表明BmATL1和BmATL2在家蚕5龄第3天幼虫各组织都有低量表达,BmATL3和BmATL4在血细胞中特异高量表达。综合分析提示:BmATL1与人类和果蝇Atlastin的分子质量、结构域和表达谱特征相似。

The hereditary spastic paraplegias（HSPs） are a group of inherited human neurological disorders causing increased stiffness and overactive muscle reflexes.Among genes underlying HSPs,Atlastin encodes a protein with a typical GTP binding（GBP） domain and two adjacent transmembrane regions.Atlastin is located on membranes of Golgi apparatus and endoplasmic reticulum,involving in vesicle trafficking.By searching against the silkworm（Bombyx mori） genome sequence,we identified 4 Atlastin genes,designated as BmATL1 to BmATL4,on the basis of homology analysis with Atlastin genes from Homo sapiens and Drosophila melanogaster.All four BmATLs have a conserved dynamin-like GBP domain,among which BmATL1 and BmATL2 have a molecular mass of about 60 kD with two adjacent transmembrane regions,and BmATL3 and BmATL4 have a molecular mass of about 85 kD without transmembrane region.Expression pattern analyses revealed that BmATL1 and BmATL2 were lowly expressed in all tissues of silkworm larvae on day 3 of the 5th instar,while BmATL3 and BmATL4 were highly expressed in silkworm hemocytes.The above analyses suggest that BmATL1 is similar to Atlastin of H.sapiens and D.melanogaster in molecular mass,structural domains,and expression pattern.