TRANSCRIPTIONAL REPRESSION IN THE DROSOPHILA EMBRYO
TRANSCRIPTIONAL REPRESSION IN THE DROSOPHILA EMBRYO
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DOI：
10.1098/rstb.1995.0111
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发表时间：
1995-09-29
期刊：
影响因子：
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通讯作者：
LEVINE, M
中科院分区：
文献类型：
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作者：
GRAY, S;CAI, H;LEVINE, M
在果蝇胚胎中，转录抑制是将粗糙的母体梯度转化为组织分化的尖锐区域所必需的。将有证据表明，一些胚胎抑制子通过短距离“猝灭”机制起作用，即抑制子在短距离（约50磅/秒）内阻断靶增强子内邻近的激活子。这种类型的抑制可以解释不同的增强子如何在复杂的模块化启动子中自主工作。然而，至少有一种抑制因子在早期胚胎中通过远程或沉默机制起作用。沉默子与给定增强子的结合导致复合启动子内所有增强子的失活。对染色质边界元件的分析表明，沉默子和增强子可能通过不同的机制起作用。我们推测沉默子限制了复杂启动子的进化。
Transcriptional repression is essential for the conversion of crude maternal gradients into sharp territories of tissue differentiation in the Drosophila embryo. Evidence will be presented suggesting that some of the embryonic repressors function through a short-range 'quenching' mechanism, whereby a repressor works over short distances (ca. 50 b.p.) to block neighbouring activators within a target enhancer. This type of repression can explain how different enhancers work autonomously within complex modular promoters. However, at least one of the repressors operating in the early embryo works through a long-range, or silencing, mechanism. The binding of a silencer to a given enhancer leads to the inactivation of all enhancers within a complex promoter. The analysis of chromatin boundary elements suggest that silencers and enhancers might work through distinct mechanisms. We speculate that silencers constrain the evolution of complex promoters.