鲢（Hypophthalmichthys molitrix）肿瘤坏死因子基因的克隆与表达分析

Gene cloning and expression of tumor necrosis factor （TNF） from silver carp （Hypophthalmichthys molitrix）

肿瘤坏死因子（TNF）是一种炎症细胞因子，在非特异性免疫系统中发挥着重要作用。TNF由单核细胞或巨噬细胞产生，能直接造成肿瘤细胞的死亡，并参与机体炎症和免疫应答的调节。用RACE（rapid amplification of cDNA ends）-PCR方法，从鲢总RNA反转录产物中获得了1254 bp TNF cDNA全序列。该序列包含394bp的5’端非编码区，398 bp的3’端非编码区和462bp的开放阅读框。鲢TNF的开放阅读框编码239个氨基酸，其中包含构成一对二硫键的2个保守半胱氨酸。同时利用RT-PCR技术，对该基因在鲢鱼体内不同组织之间的表达差异进行了分析研究，结果表明鲢TNF mRNA主要在脑、鳃和头肾中表达，肠和脾中有少量表达，而在肝中几乎没有表达。

Tumor necrosis factor （TNF） is a inflammatory cytokine, which plays a an important role in nonspecific immunology system. TNF is produced by monocyte or macrophages, in response to inflammation, infection and other physiological challenges. There were 1254 bp TNF cDNA sequences in the reverse transcription product. The cDNA sequence contained 394 bp 5＇UTR, 398 bp 3＇UTR and 462 bp open reading frame （ORF） which could translate a putative peptide of 239 amino acids including two cysteines. The expression analysis using RT-PCR showed that the silver carp TNF gene was constitutively expressed in the head-kidney, brain and branchia of the unstimulated fish.