鸡胚圆锥动脉干缺损相关基因差异表达的研究

目的 通过检测剔除心脏神经嵴的异常鸡胚心脏组织与正常心脏组织之间在发育过程中存在差异表达的基因，探索心脏圆锥动脉干缺损（CTD）发生的相关基因。方法 用电极刺激方法在鸡胚发育早期破坏心脏神经嵴，建立圆锥动脉干缺损模型。应用抑制消减杂交法（SSH）筛选出在正常心脏组织表达，但在异常心脏组织中表达减少或不表达的原因，构建减数杂交文库，用cDNA芯片技术验证，并进行测序。结果 建立了含261个克隆的cDNA减数文库，经验证有83个克隆在实验组与对照组之间存在明显的表达差异（31．8％)。随机选15个克隆测序，最后确定7种基因。经Genebank查询发现有一cDNA片段与鸡（Gallus)DEAD-box解旋酶mRNA基因序列100％同源。结论 在剔除心脏神经嵴造成圆锥动脉干缺损畸形的过程中，有多个基因参与和调节。DEAD－box解旋酶基因的缺失可能是造成心脏CTD畸形的原因之一。

Differential expression of conotruncal defect-related genes in chick embryos LIU fang, CHEN Shubao, GU Xuefan, et al. Xinhua Hospital, The Second Medical University, Shanghai 200092, China

Objective Conotruncal defects (CTD) is a common type of cyanotic congenital heart defects. There is a close relation between cardiac neural crest and cardiac conotruncal development. The purpose of this study was to determine conotruncal defect-related genes by way of discovering differentially expressed messages between cardiac neural crest ablated heart and normal heart during development. Methods Experimental chick embryos were subjected to cardiac neural crest ablation using electric stimulation. Suppression subtractive hybridization (SSH) was used to discover messages decreased or not expressed in outflow tract tissues without cardiac neural crest cells. A subtractive library was constructed and cDNA chip was used to identify significant difference. Finally, sequencing was done. Results A subtractive library containing 261 clones was constructed. Eighty-three clones (31.8%) were identified to be significantly differentially expressed by cDNA chip. Fifteen clones were sequenced and 7 kinds of cDNA fragments were identified. One was known as Gallus DEAD-box RNA helicase mRNA. Conclusion There are many kinds of genes taking part in the cardiac conotruncal development. There is a potential relation between DEAD-box helicase genes and pathogenesis of CTD. SSH was an efficient novel method to discover the differentially expressed genes.