鲤神经球蛋白基因序列与低氧表达分析  

Analysis of common carp neuroglobin gene sequence and hypoxia expression

作　　者：赵紫霞[1] 曹顶臣[2] 匡友谊[2] 邓海霞[1] 张研[1] 徐茹[1] 李炯棠[1] 徐鹏[1] 孙效文[1,2] 

机构地区：[1]中国水产科学研究院生物技术研究中心,北京100141 [2]中国水产科学研究院黑龙江水产研究所,黑龙江哈尔滨150070

出　　处：《水产学报》2014年第3期325-332,共8页Journal of Fisheries of China

基　　金：国家"八六三"高技术研究发展计划(2011AA100401);中央级公益性科研院所基本科研业务费专项(2012C014)

摘　　要：为深入了解鲤珠蛋白家族的基因组成和表达模式,及其与低氧适应能力的相关性,本实验通过鲤基因组框架图比对和全长cDNA文库筛查,获得鲤神经球蛋白(neuroglobin,Ngb)基因完整序列,证实鲤不仅具有独特的脑组织特异表达的II型肌红蛋白(myoglobin-2,Mb-2)基因,也具有Ngb珠蛋白基因,实时荧光定量PCR实验显示,该基因在脑组织特异性表达,并呈现出低氧应答特征。基因结构和系统发生分析表明,鱼类Ngb基因高度保守,鲤Ngb蛋白可能与斑马鱼直系同源蛋白具有相似的结构及功能,而与鲤Mb-2存在明显差异。鲤Ngb基因表达量在两个品系间存在显著差异,耐低氧能力强的散鳞镜鲤Ngb基因表达量高于荷包红鲤抗寒品系。研究表明,鲤Ngb基因可能以与Mb-2基因分工协作的方式共同实现脑组织供氧,执行应对低氧胁迫的神经保护功能,在鲤低氧适应中具有重要作用。The study aimed to better understand the constitution and expression pattern of common carp （ Cyprinus carpio） globin family, and their contributions to hypoxia adaptation of the species. Complete gene sequence of common carp neuroglobin（Ngb） was obtained by BLAST searching in draft genome sequence and screening in full-length cDNA library, proving that Ngb gene co-existed in common carp genome with myoglobin-2 （Mb-2）, a unique paralog of globin previously reported to be specifically expressed in brain. Quantitative real-time PCR results indicated that common carp Ngb gene expression was brain-specific and hypoxia responsive. Ngb expression was up-regulated during the aquatic surface respiration, and followed by a decline when the fish fell into coma,then no significant change in Ngb expression was observed during the reoxygenation recovery. Analysis on gene structure and phylogeny indicated that teleost Ngb genes were highly conserved, suggesting that common carp Ngb might have similar protein structure and biological functions to its zebrafish ortholog, while distinct from the paralogous Mb-2. Expression quantity was significantly different between two common carp strains with distinct hypoxia tolerance. Nearly 10 times higher Ngb expression was detected in the hypoxia tolerant mirror carp. These results suggested that Ngb and Mb-2 might serve the brain in different ways, to accomplish better oxygen delivery and neuron protection against hypoxia, playing an important role in hypoxia adaptation of common carp.

关 键 词：鲤 神经球蛋白 脑组织特异性表达 低氧应答 低氧适应 

分 类 号：Q175[生物学—水生生物学] S917.4[生物学—普通生物学]