Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Germany.
Present address: Clinical and Molecular Virology, Friedrich-Alexander University, 91054, Erlangen, Germany.
Hereditas. 2021 Nov 4;158(1):41. doi: 10.1186/s41065-021-00209-6.
Many transcription factors are involved in the formation of the brain during the development of Drosophila melanogaster. The transcription factor Earmuff (Erm), a member of the forebrain embryonic zinc finger family (Fezf), is one of these important factors for brain development. One major function of Earmuff is the regulation of proliferation within type II neuroblast lineages in the brain; here, Earmuff is expressed in intermediate neural progenitor cells (INPs) and balances neuronal differentiation versus stem cell maintenance. Erm expression during development is regulated by several enhancers.
In this work we show a functional analysis of erm and some of its enhancers. We generated a new erm mutant allele by gene targeting and reintegrated Gal4 to make an erm enhancer trap strain that could also be used on an erm mutant background. The deletion of three of the previously analysed enhancers showing the most prominent expression patterns of erm by gene targeting resulted in specific temporal and spatial defects in defined brain structures. These defects were already known but here could be assigned to specific enhancer regions.
This analysis is to our knowledge the first systematic analysis of several large enhancer deletions of a Drosophila gene by gene targeting and will enable deeper analysis of erm enhancer functions in the future.
在果蝇大脑发育过程中，许多转录因子参与脑的形成。转录因子 Earmuff（Erm）是前脑胚胎锌指家族（Fezf）的成员之一，是脑发育的重要因子之一。Earmuff 的主要功能之一是调节脑内 II 型神经母细胞谱系中的增殖；在此，Earmuff 表达于中间神经前体细胞（INP）中，并平衡神经元分化与干细胞维持。Erm 的表达在发育过程中受几个增强子调控。
在这项工作中，我们对 erm 及其一些增强子进行了功能分析。我们通过基因靶向生成了一个新的 erm 突变等位基因，并重新整合了 Gal4，以制作一个 erm 增强子陷阱品系，该品系也可以在 erm 突变背景下使用。通过基因靶向删除三个以前分析过的增强子，这些增强子表现出 erm 最显著的表达模式，导致特定的脑结构在时间和空间上出现缺陷。这些缺陷以前已经知道，但在这里可以被分配到特定的增强子区域。
据我们所知，这是首次对果蝇基因的几个大的增强子缺失进行的系统基因靶向分析，这将使我们能够在未来更深入地分析 erm 增强子的功能。
