Abstract:
Drosophila melanogaster has played a paramount role in epigenetics, the study of changes in gene function inherited through mitosis or meiosis that are not due to changes in the DNA sequence. By analyzing simple phenotypes, such as the bristle position or cuticle pigmentation, as read-outs of regulatory processes, the identification of mutated genes led to the discovery of major chromatin regulators. These are often conserved in distantly related organisms such as vertebrates or even plants. Many of them deposit, recognize, or erase post-translational modifications on histones (histone marks). Others are members of chromatin remodeling complexes that move, eject, or exchange nucleosomes. We review the role of D. melanogaster research in three epigenetic fields: Heterochromatin formation and maintenance, the repression of transposable elements by piRNAs, and the regulation of gene expression by the antagonistic Polycomb and Trithorax complexes. We then describe how genetic tools available in D. melanogaster allowed to examine the role of histone marks and show that some histone marks are dispensable for gene regulation, whereas others play essential roles. Next, we describe how D. melanogaster has been particularly important in defining chromatin types, higher-order chromatin structures, and their dynamic changes during development. Lastly, we discuss the role of epigenetics in a changing environment.
摘要:
果蝇在表观遗传学中起着至关重要的作用,通过有丝分裂或减数分裂遗传的基因功能变化的研究,这些变化不是由于DNA序列的变化。通过分析简单的表型,如刷毛位置或角质层色素沉着,作为监管程序的宣读,突变基因的鉴定导致了主要染色质调节因子的发现。这些通常在远亲生物如脊椎动物或甚至植物中保守。他们中的许多人存款,认识到,或擦除组蛋白(组蛋白标记)上的翻译后修饰。其他人是移动的染色质重塑复合物的成员,弹出,或者交换核小体。我们回顾了D.melanogaster研究在三个表观遗传领域的作用:异染色质形成和维持,piRNAs对转座因子的抑制,以及拮抗Polycomb和Trithorax复合物对基因表达的调节。然后,我们描述了黑腹D.melanogaster中可用的遗传工具如何允许检查组蛋白标记的作用,并表明某些组蛋白标记对于基因调控是可有可无的,而其他人则扮演重要角色。接下来,我们描述了D.melanogaster如何在定义染色质类型方面特别重要,高阶染色质结构,以及它们在发展过程中的动态变化。最后,我们讨论了表观遗传学在不断变化的环境中的作用。