Differential Gene Expression in Aging-Related Embryonic Development

心血管科学实验室是 致力于鉴定那些基因产物， 在胚胎发育中的差异表达， 胚胎干细胞心脏发育模型的建立 和胚胎癌细胞分化， 与遗传学实验室的互动及其在以下方面的专业知识 制作和分析专门的库和芯片。与 锌指在心脏中作用的研究进展 转录因子（GATA4），同源域含有 转录因子（Nkx2.5）和碱性螺旋环螺旋蛋白 （eHAND和dHAND），鉴定新的转录因子 仅基于序列数据应该是可能的;然而， 导致心脏诱导的因素以及 差异是完全未知的。 serial analysis of gene 表达（SAGE）产生定量的，代表性的， 全面的差异基因表达谱。使用几 胚胎干细胞精确发育曲线中的时间点 或癌细胞分化为心肌细胞，SAGE分析 可以产生数十个转录本的定量表征， 成千上万的成绩单，这是更快速和经济 比其他技术。在过去的四个月里， 一种基于RT-PCR的技术，以确定时间点， 许多中胚层和心脏限制性基因产物是 在体外分化的EC衍生的心肌细胞中表达。 结果显示，最早的收缩发生在第5.5天， 分化（3 + 2.5或4 + 1.5）。一些收缩蛋白基因 (beta MHC）在分化的第三天之前表达， 但我们发现， MLC2V相对较晚开始（α MHC为5 + 0.5和3 + 1 和MLC2V。加塔-4，一种转录因子， 在心脏收缩蛋白基因表达的调节中， 高度存在于分化的最早阶段， 分化3 + 1.5天，其表达降低至 成年人心脏组织这表明，这一时期 对应于心脏分化的早期阶段。我们 用SAGE方法分析表达序列， 在这段时间里的轮廓。这项工作正在进行中。

The Laboratory of Cardiovascular Science is committed to identifying those gene products which are differentially expressed in embryonic development through exploitation of the cardiac developmental model of embryonic stem and embryonic carcinoma cell differentiation and through interaction with the Laboratory of Genetics and their expertise in making and analyzing specialized libraries and chips. With the recent developments in heart regarding the role of zinc-finger transcription factors (GATA4), homeodomain containing transcription factors (Nkx2.5) and basic helix loop helix proteins (eHAND and dHAND), identification of novel transcription factors should be possible based on sequence data alone; however, the factors responsible for cardiac induction and many aspects of differentiation are entirely unknown. Serial analysis of gene expression (SAGE) yields a quantitative, representative and comprehensive differential gene expression profile. Using several time points in the precise developmental profile of embryonic stem or carcinoma cell differentiation to cardiomyocytes, SAGE analysis can generate a quantitative transcript characterization of tens of thousands of transcripts that is much more rapid and economical than other techniques. During the past four months we have used an RT-PCR based technique to determine the time points where a number of mesodermal and cardiac-restricted gene products are expressed in in vitro differentiated EC derived cardiomyocytes. Results show that the earliest contractions occur on Day 5.5 of differentiation (3+2.5 or 4+1.5). Some contractile protein genes (beta MHC) are expressed before the third day of differentiation , but we show that a clear induction of expression of a alpha MHC and MLC2V starts relatively later (5+0.5 and 3+1 for alpha MHC and MLC2V respectively. GATA-4, a transcription factor involved in the regulation of cardiac contractile protein gene expression is highly present in the earliest stages of differentiation, and form 3+1.5 days of differentiation, its expression is reduced to the level of adult heart tissue. This indicates that this time period corresponds to an early stage of cardiac differentiation. We are using the protocols of SAGE to analyze the expressed sequence profile during this time period . This work is ongoing.