Dosage compensation, which corrects for the imbalance in X-linked gene expression between XX females and XY males, represents a model for how genes are targeted for coordinated regulation. However, the mechanism by which dosage compensation complexes identify the X chromosome during early development remains unknown because of the difficulty of sexing embryos before zygotic transcription using X- or Y-linked reporter transgenes. We used meiotic drive to sex Drosophila embryos before zygotic transcription and ChIP-seq to measure the dynamics of dosage compensation factor targeting. The Drosophila male-specific lethal dosage compensation complex (MSLc) requires the ubiquitous zinc-finger protein chromatin-linked adaptor for MSL proteins (CLAMP) to identify the X chromosome. We observe a multi-stage process in which MSLc first identifies CLAMP binding sites throughout the genome, followed by concentration at the strongest X-linked MSLc sites. We provide insight into the dynamics of binding site recognition by a large transcription complex during early development.

中文翻译：

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果蝇早期发育过程中剂量补偿的雄性X染色体的靶向。

剂量补偿可纠正XX雌性和XY雄性之间X连锁基因表达的不平衡，代表了如何针对基因进行协调调控的模型。然而，由于在使用X或Y连锁的报告基因转基因进行合子转录之前难以对性别进行性别区分，因此剂量补偿复合物在早期发育过程中鉴定X染色体的机制仍然未知。在合子转录和ChIP-seq之前，我们使用减数分裂驱动对果蝇的性进行了测量，以测量剂量补偿因子靶向的动力学。果蝇雄性特异性致死剂量补偿复合物（MSLc）需要用于MSL蛋白（CLAMP）的普遍存在的锌指蛋白染色质链接适配器，以鉴定X染色体。我们观察到一个多阶段过程，其中MSLc首先识别整个基因组中的CLAMP结合位点，然后在最强的X连锁MSLc位点进行浓缩。我们提供了对大型转录复合体在早期发育过程中结合位点识别动力学的洞察力。