外源性视黄酸对斑马鱼Tbx1基因的影响  

Effect of external retinoic acid on Tbxl gene during zebrafish embryogenesis

作　　者：张立凤[1] 桂永浩[1] 钟涛 王跃祥[3] 钱林溪[3] 董永新[3] 蒋璆[3] 孙淑娜[1] 宋后燕[3] 

机构地区：[1]复旦大学附属儿科医院心血管中心,上海200032 [2]美国Vanderbilt大学医学院细胞生物学实验室 [3]复旦大学分子生物学重点实验室

出　　处：《中华儿科杂志》2007年第4期267-271,共5页Chinese Journal of Pediatrics

基　　金：卫生部专项课题资助(2002BA709808)

摘　　要：目的观察外源性视黄酸对斑马鱼心脏发育的影响,探讨视黄酸对 Tbx1基因在斑马鱼胚胎发育中表达的影响。方法采用化学遗传学的方法在斑马鱼胚胎发育至胚胎受精后12.5 h时给予5×10^(-8)mol/L 和10^(-7)mol/L 外源性视黄酸处理1.5 h。采用胚胎整体原位杂交和实时荧光定量 PCR 方法观察外源性视黄酸对斑马鱼胚胎发育过程中 Tbx1基因时空表达模式的影响。结果整体原位杂交显示 Tbx1在斑马鱼胚胎发育过程中主要在咽弓、心脏和耳囊表达。在12.5 hpf 给予斑马鱼胚胎5×10^(-8)mol/L 或10^(-7)mol/L 视黄酸处理1.5 h,可以导致 Tbx1基因在咽弓和心脏的表达明显下调。与5×10^(-8)mol/L 视黄酸处理组相比,10^(-7)mol/L 视黄酸对 Tbx1基因表达的抑制作用更为明显。结论视黄酸可以调节斑马鱼发育过程 Tbx1基因的表达,且这种调控作用具有明显的剂量依赖性。视黄酸是导致胚胎发育过程中 Tbx1表达异常的主要非遗传因素,并可进一步导致咽弓和心脏的发育异常。Objective DiGeorge/de122q11 syndrome is one of the most common genetic causes of outflow tract and aortic arch defects in human. DiGeorge/de122q11 is thought to involve an embryonic defect restricted to the pharyngeal arches and the corresponding pharyngeal pouches. Previous studies have evidenced that retinoic acid （RA） signaling is definitely indispensable for the development of the pharyngeal arches. Tbxl, one of the T-box containing genes, is proved to be the most attractive candidate gene for DiGeorge/de122q11 syndrome. However, the interaction between RA and Tbxl has not been fully investigated. Exploring the interaction will contribute to discover the molecular pathways disrupted in DiGeorge/de122q11 syndrome, and will also be essential for understanding genetic basis for congenital heart disease. It now seems possible that genes and molecular pathways disrupted in DiGeorge syndrome will also account for some isolated cases of congenital heart disease. Accordingly, the present study aimed to extensively study the effects of external RA on the cardiac development and Tbxl expression during zebrafish embryogenesis. Methods The chemical genetics approach was applied by treating zebrafish embryos with 5 × 10^-8 mol/L RA and 10^-7 mol/L RA at 12.5 hour post fertilization （hpf）. The expression patterns of Tbxl were monitored by whole-mount in situ hybridization and quantitative real-time RT-PCR, respectively. Results The zebrafish embryos treated with 5 × 10^-8 mol/L RA and 10^-7 mol/L RA for 1.5 h at 12. 5 hpf exhibited selective defects of abnormal heart tube. The results of whole-mount in situ hybridization with Tbxl RNA probe showed that Tbxl was expressed in cardiac region, pharyngeal arches and otic vesicle during zebra_fish embryogenesis. RA treatment led to a distinct spatio-temporal expression pattern for Tbxl from that in wild type embryo. The real-time PCR analysis showed that Tbxl expression levels were markedly reduced by RA treatment. Tbxl expression in the pharyngeal arches and heart wer

关 键 词：维甲酸 斑马鱼 鳃区 心脏 T盒域蛋白质类 

分 类 号：R725.9[医药卫生—儿科]