苯丙氨酸羟化酶在日本刺沙蚕脑内的表达分析

The expression of phenylalanine hydroxylase in the brain of ragworm Neanthes japonica (Polychaeta, Annelida)

摘要:

苯丙氨酸羟化酶 (PAH) 是芳香族氨基酸羟化酶家族 (AAAHs) 的一员，催化苯丙氨酸 (Phe) 转化为酪氨酸 (Tyr)。运用Western blotting技术检测沙蚕PAH免疫原性。制作沙蚕头部石蜡切片，运用免疫组织化学技术，检测PAH蛋白表达定位情况。解剖剥离沙蚕脑组织，提取总RNA，运用RT-PCR技术克隆pah基因片段，构建质粒并转化入大肠杆菌中扩增，挑单一均匀菌落培养，双酶切鉴定后测序并比对同源性。Western blotting结果表明pah表达的蛋白存在于沙蚕脑内，免疫组化标记技术结果表明苯丙氨酸羟化酶主要分布在日本刺沙蚕前脑中腹侧、中脑背侧和两侧。RT-PCR结果表明沙蚕脑内存在苯丙氨酸羟化酶基因，且与多种动物pah具有同源性。在蛋白质和核酸水平鉴定了低等环节动物日本刺沙蚕脑组织内苯丙氨酸羟化酶的存在，为进一步研究无脊椎动物中枢神经系统内芳香族氨基酸羟化酶的基因分化奠定基础。

Abstract:

Phenylalanine hydroxylase (PAH) is a member of aromatic amino acid hydroxylase (AAAHs) family, and catalyze phenylalanine (Phe) into tyrosine (Tyr). Using immunological and RT-PCR methods to prove the existence of phenylalanine hydroxylase (PAH) gene in the brain of Neanthes japonica in protein and nucleic acid level. Using Western blotting to detect the pah immunogenicity of Neanthes japonica. Making paraffin sections and using immunohistochemical technique to identify the presence and distribution of the phenylalanine hydroxylase gene in the brain of Neanthes japonica. Clone pah gene from the brain of Neanthes japonica by RT-PCR, constructing plasmid and transferring into E. coli to amplification, picking a single homogeneous colony, double digesting then making sequence and comparing homology. Western blotting results showed that the expression of the protein is present in Neanthes japonica brain, immunohistochemistry technique results showed that phenylalanine hydroxylase mainly expressed in abdominal of forebrain, dorsal and sides of midbrain. RT-PCR technique results showed that the phenylalanine hydroxylase exist in the brain of Neanthes japonica and has a high homology with others animals. PAH is present in the lower organisms Neanthes japonica, in protein and nucleic acid level. Which provide the foundation for further study the evolution of aromatic amino acid hydroxylase genes in invertebrate.