文章分析了福寿螺(Pomacea canaliculata)细胞色素P450(CYPs)的结构、表达特征及四聚乙醛代谢与细胞色素P450表达水平的相关性.应用cDNA末端快速扩增技术(rapid amplification of cDNA ends,RACE)克隆获得福寿螺CYPs基因cDNA全长2 523 bp,命名为CYP3192A1,含1个开放阅读框(ORF),编码517个氨基酸,具有血红素结合区F**G***C*G、K螺旋(E**R)、I螺旋(AG*ET)、C螺旋(W***R)等高度保守序列及跨膜螺旋(12～34号氨基酸).聚类分析显示福寿螺CYP3192A1是细胞色素P450新家族成员,与CYP3A亚家族序列同源性较高.荧光定量PCR(real time quantitative PCR,RT-qPCR)分析显示,福寿螺CYP3192A1基因表达量存在显著的性别及组织差异性(P<0.05),表现为雌性表达量高于雄性,肠和鳃表达量最丰富,肝和胃次之,心和腹足中少量表达;四聚乙醛对福寿螺CYP3192A1表达的影响为"低浓度诱导,高浓度诱导期缩短并提前".结果表明四聚乙醛处理能够显著诱导福寿螺CYP3192A1表达,与CYP3192A1表达量增加紧密相关,福寿螺CYP3192A1过表达可能在四聚乙醛代谢抗性中起重要作用.%The study investigates the structure and expression features of Pomacea canaliculata cytochrome P450,and explores the correlation of metaldehyde treatment and cytochrome P450 expression level.A full-length cDNA of CYP3192A1 from P.canaliculata with total length of 2 523 bp was obtained by RACE,including an open reading frame(ORF)encoding 517 amino acids,which had a heme-binding domain F**G*** C*G,helix K(E**R),helix I(AG*ET),helix C(W***R)and trans-membrane helix(12～34 amino acids).Blast and phylogenetic analyses suggest P.canaliculata CYP3192A1 is a member of a novel CYP450 family,with high similarity with CYP3A subfamily.The RT-qPCR suggests that CYP3192A1 has gender-specific and tissue specific expression(P<0.05).Expression in female P.canaliculata was higher than in males;expression amounts in intestinal and gill were the highest,followed by those in liver and stomach,and were the lowest in heart and pleopod.The influence of metaldehyde to CYP3192A1 expression shows a trend of induction at low concentration,shortened and advanced induction period at high concentration.It is demonstrated that there is close correlation between CYP3192A1 expression and metaldehyde treatment,and the induced expression of CYP3192A1 might play an important role in metaldehyde metalbolism.
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