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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。
The vertebrate Hox gene is an important growth and development regulatory gene that encodes a transcription factor with a helix-turn-helix structure that binds to and activates expression in specific regions of downstream target genes, thereby regulating vertebrate embryonic development Shaft shape is completed. The full-length cDNA sequence of HoxB1b gene from Megalobrama amblycephala was cloned by rapid amplification of cDNA ends (RACE) and its expression pattern was studied. The results showed that: (1) The cDNA of HoxB1b gene was 1 479 bp in length, including a 921 bp reading frame encoding 306 amino acid residues. The cluster analysis showed that the gene was associated with zebrafish, , And the similarities of barley were 89%, 45% and 40%, respectively, which were conservative in vertebrates. (2) The results of RT-PCR showed that HoxB1b was expressed in all stages of embryonic development Stable expression, but no expression of the gene was detected in mature eggs, indicating that the gene is a non-maternal expression type. Further in situ hybridization of whole embryos showed that HoxB1b had obvious spatial expression differences in embryos at different stages of boutonnus japonicus. Embryos at 20 h post fertilization (20 hpf) mainly expressed in the hindbrain after 40 h (40 hpf) In addition to the embryonic brain expression in the pectoral fins are also detected expression; (3) HoxB1b gene expression in some tissues or organs of the fish head group, and the gene expression in males and females there is a certain difference. In conclusion, the function of HoxB1b gene is closely related to the development of the hindbrain and pectoral fins on the anterior and posterior axes of embryos, and plays an important physiological role in the formation of fish-related tissues.