collier transcription in a single Drosophila muscle lineage:: the combinatorial control of muscle identity
collier transcription in a single Drosophila muscle lineage:: the combinatorial control of muscle identity
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DOI：
10.1242/dev.008409
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发表时间：
2007-12-15
期刊：
影响因子：
4.6
通讯作者：
Vincent, Alain
中科院分区：
文献类型：
--
作者：
Dubois, Laurence;Enriquez, Jonathan;Vincent, Alain
果蝇肌肉特性的确定是一个多步骤的过程：早期的位置信息定义了称为肌前簇的能力群，从中选择肌肉前体细胞，然后不对称地将前体细胞分裂为肌肉创建细胞(FCS)。每个Fc都是形成单个肌肉的种子，具有形态和功能特性，这些特性被认为是反映其创始人表达的转录因子的组合。然而，目前还不清楚早期模式和肌肉特异性分化之间的联系。我们解决了这个问题，使用Collier(Col；也称为纽结)表达作为DA3肌肉特性的决定因素和读出。对驱动DA3肌肉特异性表达的COL上游区域的研究表明，存在三个独立的顺式调节阶段，与不同中胚层转录因子的保守结合部位相关。在COL和鹦鹉螺(NAU)功能丧失和功能获得的条件下，对COL转录的检测表明，在与DA3 Fc融合的“幼稚”成肌细胞中，这两种因素都是激活COL所必需的，从而确保所有DA3肌纤维核表达相同的识别程序。综上所述，这些结果表明，不同的顺式调控元件控制着肌祖细胞和肌纤维核中同一性因子的表达，并直接支持肌肉同一性的组合控制概念。
Specification of muscle identity in Drosophila is a multistep process: early positional information defines competence groups termed promuscular clusters, from which muscle progenitors are selected, followed by asymmetric division of progenitors into muscle founder cells (FCs). Each FC seeds the formation of an individual muscle with morphological and functional properties that have been proposed to reflect the combination of transcription factors expressed by its founder. However, it is still unclear how early patterning and muscle-specific differentiation are linked. We addressed this question, using Collier (Col; also known as Knot) expression as both a determinant and read-out of DA3 muscle identity. Characterization of the col upstream region driving DA3 muscle specific expression revealed the existence of three separate phases of cis-regulation, correlating with conserved binding sites for different mesodermal transcription factors. Examination of col transcription in col and nautilus (nau) loss-of-function and gain-of-function conditions showed that both factors are required for col activation in the 'naive' myoblasts that fuse with the DA3 FC, thereby ensuring that all DA3 myofibre nuclei express the same identity programme. Together, these results indicate that separate sets of cis-regulatory elements control the expression of identity factors in muscle progenitors and myofibre nuclei and directly support the concept of combinatorial control of muscle identity.