MCS9.7 enhancer activity is highly, but not completely, associated with expression of Irf6 and p63.
MCS9.7 enhancer activity is highly, but not completely, associated with expression of Irf6 and p63.
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DOI：
10.1002/dvdy.22786
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发表时间：
2012-02
期刊：
影响因子：
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通讯作者：
Schutte BC
中科院分区：
文献类型：
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作者：
Fakhouri WD;Rhea L;Du T;Sweezer E;Morrison H;Fitzpatrick D;Yang B;Dunnwald M;Schutte BC
干扰素调节因子6（IRF 6）的DNA变异会导致口面裂的风险，包括常见的DNA变异rs642961。该DNA变体位于IRF 6转录起始位点（MCS9.7）上游9.7 kb的多物种保守序列中。MCS9.7元件显示具有增强子活性，其模拟瞬时转基因胚胎中胚胎第11.5天内源性Irf 6的表达，并且还含有反式激活IRF 6表达的p63结合位点。为了分析MCS9.7增强子是否足以驱动IRF 6表达，我们产生了携带MCS9.7-lacZ转基因的稳定转基因鼠系。我们假设MCS9.7足以概括胚胎发育过程中其他时间点Irf 6的内源性表达。我们观察到MCS9.7活性在大多数组织中重现了内源性Irf 6表达，但在E14.5的内侧缘上皮（E14.5）中没有，此时Irf 6表达在第二腭融合期间很高。此外，虽然MCS9.7活性和Irf 6表达与p63表达相关，但我们观察到MCS9.7活性和Irf 6表达在牙周膜中，尽管p63不存在。这些数据表明MCS9.7增强子活性不足以重现IRF 6表达，并且p63表达对于IRF 6的反式激活并不总是必需的也不总是充分的。
DNA variation in Interferon Regulatory Factor 6 (IRF6) contributes risk for orofacial clefting, including a common DNA variant rs642961. This DNA variant is located in a multi-species conserved sequence that is 9.7 kb upstream from the IRF6 transcriptional start site (MCS9.7). The MCS9.7 element was shown to possess enhancer activity that mimicked the expression of endogenous Irf6 at embryonic day 11.5 in transient transgenic embryos, and also contains a p63 binding site that transactivates IRF6 expression. To analyze whether the MCS9.7 enhancer is sufficient to drive IRF6 expression, we generated stable transgenic murine lines that carry a MCS9.7-lacZ transgene. We hypothesized that MCS9.7 was sufficient to recapitulate the endogenous expression of Irf6 at other time-points during embryonic development. We observed that MCS9.7 activity recapitulated endogenous Irf6 expression in most tissues, but not in the medial edge epithelium (MEE) at E14.5, when Irf6 expression was high during secondary palatal fusion. Also, while MCS9.7 activity and Irf6 expression were associated with p63 expression, we observed MCS9.7 activity and Irf6 expression in periderm, although p63 was absent. These data suggest that MCS9.7 enhancer activity is not sufficient to recapitulate IRF6 expression, and that p63 expression is not always necessary nor sufficient for transactivation of IRF6.