Schwartz R J, Olson E N
Department of Cell Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA.
Development. 1999 Oct;126(19):4187-92. doi: 10.1242/dev.126.19.4187.
Heart formation in Drosophila is dependent on the homeobox gene tinman. The homeobox gene Nkx2-5 is closely related to tinman and is the earliest known marker for cardiogenesis in vertebrate embryos. Recent studies of cis-regulatory elements required for Nkx2-5 expression in the developing mouse heart have revealed an extraordinary array of independent cardiac enhancers, and associated negative regulatory elements, that direct transcription in distinct regions of the embryonic heart. These studies demonstrate the modularity in cardiac transcription, in which different regulatory elements respond to distinct sets of transcription factors to control gene expression in different compartments of the developing heart. We consider the potential mechanisms underlying such transcriptional complexity, its possible significance for cardiac function, and the implications for evolution of the multichambered heart.
果蝇的心脏形成依赖于同源异型框基因tinman。同源异型框基因Nkx2 - 5与tinman密切相关，是脊椎动物胚胎中心脏发生最早已知的标志物。最近对发育中的小鼠心脏中Nkx2 - 5表达所需的顺式调控元件的研究揭示了一系列非凡的独立心脏增强子以及相关的负调控元件，它们在胚胎心脏的不同区域指导转录。这些研究证明了心脏转录的模块化，其中不同的调控元件对不同的转录因子组合做出反应，以控制发育中心脏不同区域的基因表达。我们考虑了这种转录复杂性背后的潜在机制、其对心脏功能可能的意义以及对多腔心脏进化的影响。
