Telethon Institute of Genetics and Medicine, Via P, Castellino 111, Napoli, 80131, Italy.
Genome Biol. 2010;11(6):R64. doi: 10.1186/gb-2010-11-6-r64. Epub 2010 Jun 22.
Dosage imbalance is responsible for several genetic diseases, among which Down syndrome is caused by the trisomy of human chromosome 21.
To elucidate the extent to which the dosage imbalance of specific human chromosome 21 genes perturb distinct molecular pathways, we developed the first mouse embryonic stem (ES) cell bank of human chromosome 21 genes. The human chromosome 21-mouse ES cell bank includes, in triplicate clones, 32 human chromosome 21 genes, which can be overexpressed in an inducible manner. Each clone was transcriptionally profiled in inducing versus non-inducing conditions. Analysis of the transcriptional response yielded results that were consistent with the perturbed gene's known function. Comparison between mouse ES cells containing the whole human chromosome 21 (trisomic mouse ES cells) and mouse ES cells overexpressing single human chromosome 21 genes allowed us to evaluate the contribution of single genes to the trisomic mouse ES cell transcriptome. In addition, for the clones overexpressing the Runx1 gene, we compared the transcriptome changes with the corresponding protein changes by mass spectroscopy analysis.
We determined that only a subset of genes produces a strong transcriptional response when overexpressed in mouse ES cells and that this effect can be predicted taking into account the basal gene expression level and the protein secondary structure. We showed that the human chromosome 21-mouse ES cell bank is an important resource, which may be instrumental towards a better understanding of Down syndrome and other human aneuploidy disorders.
剂量失衡是导致多种遗传疾病的原因，其中唐氏综合征是由人类 21 号染色体三体引起的。
为了阐明特定人类 21 号染色体基因的剂量失衡如何扰乱不同的分子途径，我们开发了第一个人类 21 号染色体基因的小鼠胚胎干细胞（ES 细胞）库。人类 21 号染色体-小鼠 ES 细胞库包括 32 个人类 21 号染色体基因的三倍体克隆，这些基因可以以诱导的方式过表达。每个克隆在诱导和非诱导条件下进行转录谱分析。转录响应分析的结果与受扰基因的已知功能一致。含有整条人类 21 号染色体的小鼠 ES 细胞（三体小鼠 ES 细胞）和过表达单个人类 21 号染色体基因的小鼠 ES 细胞之间的比较，使我们能够评估单个基因对三体小鼠 ES 细胞转录组的贡献。此外，对于过表达 Runx1 基因的克隆，我们通过质谱分析比较了相应的蛋白质变化与转录组变化。
我们确定只有一小部分基因在过表达于小鼠 ES 细胞时会产生强烈的转录反应，并且这种效应可以通过考虑基础基因表达水平和蛋白质二级结构来预测。我们表明，人类 21 号染色体-小鼠 ES 细胞库是一个重要的资源，它可能有助于更好地理解唐氏综合征和其他人类非整倍体疾病。
