Post-meiotic transcription and RNA localisation in Drosophila spermatid bundles

在任何生物体中，不同的细胞都有专门的功能。为了发展这些专门化，它们通过调节DNA转录成信使RNA（mRNA）来打开一些基因，关闭其他基因。精子是非常专业的，因此在其发育过程中基因表达会发生巨大变化。大多数情况发生在精子产生的早期。我们正在研究果蝇精子的形成，并发现了一组基因（我们称之为彗星和杯子），它们在精子形成的后期转录（在我们认为转录是不可能的很久之后）。在细胞内，不同的区域具有不同的功能，由细胞内蛋白质的差异定位介导。许多细胞具有固有的极性，精子又长又细，一端是细胞核，另一端是能动的尾巴。来自彗星和杯子基因的mRNA特异性地定位于发育中的精子尾部的末端/距离它们产生的细胞核1.5 mm。在这个项目中，我们将研究非常晚的基因转录的控制。我们将确定精子形成过程中转录发生的确切时间，并测试一些已知转录因子蛋白在该过程中的重要性。我们将绘制基因组DNA中对促进晚期转录重要的区域。在mRNA运输方面，我们将开发一个系统，在这个系统中，我们将把荧光mRNA注入形成精子，观察定位，并看看我们必须改变mRNA上的哪些序列才能阻止它正确定位。为了研究mRNA是如何转运的，我们将确定哪些细胞骨架元素是重要的（类似于火车轨道或道路），以及什么是转运（火车？卡车？汽车？）。该项目的第三个方面将利用遗传学来确定基因在正常精子生物学中发挥的作用。这将为我们提供线索，为什么它们的转录和mRNA定位模式如此不寻常。

Within any organism different cells have specialised functions. To develop these specialisations they turn on some genes, and turn off other genes, by regulating transcription of DNA into messenger RNA (mRNA). Sperm are extremely specialist, so show dramatic changes in gene expression during their development. Most of this happens relatively early in sperm production. We are working on fruit fly sperm formation, and have found a set of genes (that we call comets and cups) that are transcribed very late in sperm formation (long after we thought that transcription was impossible). Within cells different regions have different functions, mediated by differential localisation of proteins within the cell. Many cells have an inherent polarity / sperm are long and thin, with their nucleus at one end and a motile tail at the other. The mRNAs from the comet and cup genes are specifically localised to the very end of the tail of the developing sperm tails / 1.5mm away from the nuclei where they are made. In this project we will examine the control of the very late gene transcription. We will determine exactly when in the process of sperm formation the transcription occurs, and test the importance of some known transcription factor proteins in the process. We will map the region of genomic DNA important for promoting the late transcription. On the mRNA transport side we will develop a system in which we will inject fluorescent mRNA into forming sperm, look at localisation, and see what sequences we have to change on the mRNA to stop it localising properly. To examine how the mRNA is transported we will determine what cytoskeletal elements are important (analogous to train-tracks or roads), and what does the transporting (trains? lorries? cars?). In the third aspect of the project will use genetics to determine what role the genes play in normal sperm biology. This will give us clues as to why their transcription and mRNA localisation patterns are so unusual.