Expression profile of Sall4-null ES cells and Sall4 heterozygous ES cells

Sall4 is a mouse homolog of a causative gene of the autosomal dominant disorder known as Okihiro syndrome. We previously showed that Sall4 absence leads to lethality during peri-implantation and that Sall4-null embryonic stem (ES) cells proliferate poorly with intact pluripotency when cultured on feeder cells. However, a subsequent report indicated that shRNA-mediated Sall4 inhibition in ES cells led to a severe reduction in Oct3/4 and a secondary increase in Cdx2, which resulted in complete differentiation into the trophectoderm when cultured in the feeder-free condition. So we profiled gene expression changes when Sall4 is deleted in ES cells in the presence or absence of feeder cells. key word: embryonic stem (ES) cell, Sall4, feeder ES cells were cultured with or without mouse embryonic fibroblast (MEF) feeder cells in LIF-supplemented medium as described. To maintain the expression of Oct3/4, all ES cells were cultured in the presence of Blasticidin. Four samples were analyzed. GSM356329, GSM356330 : cultured in the absence of feeders GSM356331, GSM356332 : cultured on the feeders

Sall4是常染色体显性遗传病Okihiro综合征致病基因的小鼠同源物。我们此前的研究显示，Sall4基因缺失会导致小鼠围着床期死亡；且在饲养层细胞上培养时，Sall4敲除型胚胎干细胞（embryonic stem cell, ES细胞）虽保有完整的多能性，但增殖能力较差。然而，后续一项研究表明，在ES细胞中通过短发夹RNA（short hairpin RNA, shRNA）介导的Sall4抑制会引发Oct3/4表达显著下调，并继发导致Cdx2表达升高，最终在无饲养层培养条件下完全分化为滋养外胚层。为此，我们对存在或缺失饲养层细胞的ES细胞中Sall4缺失后的基因表达变化进行了表达谱分析。
关键词：胚胎干细胞（ES细胞）、Sall4、饲养层细胞
实验方法：ES细胞在添加白血病抑制因子（leukemia inhibitory factor, LIF）的培养基中，分别以有或无小鼠胚胎成纤维细胞（mouse embryonic fibroblast, MEF）饲养层的条件进行培养，具体操作如前文所述。为维持Oct3/4的表达，所有ES细胞均在添加杀稻瘟菌素（Blasticidin）的培养基中培养。
本研究共分析4个样本：GSM356329、GSM356330为无饲养层培养的ES细胞；GSM356331、GSM356332为饲养层培养的ES细胞。