团头鲂形态发育相关基因HoxB1b的克隆及功能研究  

Cloning and function of morphology-related gene HoxB1b in Megalobrama amblycephala

作　　者：濮剑威[1] 何珠子[1] 邹曙明[1] 

机构地区：[1]上海海洋大学农业部水产种质资源与利用重点开放实验室,上海201306

出　　处：《上海海洋大学学报》2011年第4期481-487,共7页Journal of Shanghai Ocean University

基　　金：公益性行业科研专项(200903045);上海市教育委员会曙光计划(08SG50)

摘　　要：脊椎动物Hox族基因是一类重要的生长和发育调控基因,它编码具有螺旋—转角—螺旋结构的转录因子,能与下游靶基因特定区域结合并激活表达,从而调节脊椎动物胚胎发育过程中前后轴的形态建成。利用cDNA末端快速扩增法(RACE)克隆了团头鲂(Megalobrama amblycephala)HoxB1b基因的全长cDNA序列,并研究了该基因的表达模式。结果表明:(1)团头鲂HoxB1b基因cDNA全长为1 479 bp,其中包括一个编码306个氨基酸残基的921 bp阅读框,聚类分析结果表明,该基因与斑马鱼、红鳍东方鲀、青鳉的相似度分别为89%、45%、40%,在脊椎动物中具有一定的保守性;(2)RT-PCR分析结果显示,HoxB1b在团头鲂胚胎发育过程的各时期均有稳定表达,但在成熟卵中未检测到该基因的表达,表明该基因属非母源表达类型。进一步的整胚原位杂交结果显示,HoxB1b在团头鲂不同时期胚胎存在明显的空间表达差异,受精后20 h(20 hours post fertilization,20hpf)胚胎主要在后脑表达,受精后40 h(40hpf)胚胎除了在后脑表达外,在胸鳍也检测到表达;(3)HoxB1b基因在团头鲂成鱼部分组织或器官中有表达,且在雌雄鱼中基因表达量有一定差别。综上所述,团头鲂HoxB1b基因的功能与胚胎前后轴上的后脑和胸鳍发育密切相关,并在团头鲂成鱼相关组织中具有重要生理功能。Vertebrate Hox family genes play important roles in growth and development,which encode a helix-turn-helix transcription factor and activate downstream target genes by binding the specific DNA region,to regulate the axial pattern formation during ontogeny.Changes in number and in genomic organization of Hox genes are believed to determine various morphology and new species in teleost fish.In this study,the complete cDNAs of blunt snout bream（Megalobrama amblycephala） HoxB1b gene was cloned by rapid amplification of cDNA ends（RACE）,and its expression patterns were studied.Our results showed：（1） The whole length of HoxB1b cDNA in blunt snout bream was 1 479 bp,consisting of an open reading frame（ORF） which encodes a 306 amino acid（aa） residues.Phynogenetic analysis showed that blunt snout bream HoxB1b gene demonstrated 89%,45% and 40% similarity with that of zebrafish,fugu and medaka.（2） During embryogenesis,HoxB1b was stably expressed in all stages except mature eggs,which suggested it was a non-maternal gene.Further whole embryo in situ hybridization analysis showed HoxB1b obvious spatial expression differences during embryogenesis of blunt snout bream.At early embryonic stage of 20 hours post fertilization（20hpf）,HoxB1b expressed mainly in the hindbrain,whereas its expression was also detected in the pectoral fins at the late stage of 40hpf.（3） At adult stage,the expression of HoxB1b was detected in some fish tissues,and there are some differences between male and female in different tissues.In summary,these results suggest that HoxB1b gene plays a crucial role in hindbrain and pectoral fins during embryogenesis,as well as in relative tissues in adult stage at blunt snout bream.

关 键 词：团头鲂 HoxB1b 克隆 整胚原位杂交 RT-PCR 

分 类 号：S917[农业科学—水产科学]