Dynamics and functions of small interfering RNAs in germline cells

生殖细胞中小干扰RNA的动态和功能

• 批准号: EP/X02296X/1
• 负责人: Xiaoqi Feng
• 金额: $ 24.26万
• 依托单位: John Innes Centre
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FX02296X%2F1
• 关键词: Dynamics; functions; small; interfering; RNAs

Small interfering RNAs (siRNAs) play essential roles in regulating germline functions. In flowering plants, 21-22 nt siRNAs have been implicated in the movement from sperm companion cells (called vegetative cells) to silence sperm transposons. However, the nature and silencing mechanism of the non-cell autonomous signal have remained controversial. Recently, my host lab discovered that 24-nt siRNAs produced by meiocyte nurse cells (called tapetum) drive DNA methylation reprogramming in the Arabidopsis male germline, thereby regulating genes and suppressing transposons. These tapetum siRNAs are sufficient to shape the entire de novo methylome in sperm, however, it is unclear how this is achieved given the absence of cytoplasmic connections between the tapetum and sperm.My preliminary work indicates that there are two waves of siRNA transport during germline development: the first wave from tapetal cells to meiocytes, and the second from vegetative cells to sperm. 21-22and 24 nt siRNAs are both suggested to be transported, playing important roles in post-transcriptional and transcriptional gene silencing, respectively, via interacting with cell-specific Argonaute proteins. Using a combination of cell biology, molecular genetics, single-cell-type genomics, epigenetics and biochemistry approaches, I will test these innovative hypotheses and elucidate the underlying molecular mechanisms by investigating: Obj.1) how siRNA biogenesis and transport mediate DNA methylation in the male germline, Obj.2) the origin and function of 21-22 nt siRNAs during male germline development, and Obj.3) the central role of cell-specific Argonauts in germline siRNA pathways. My investigations will open a new horizon in our understanding of plant germlines and heredity by revealing the intricate dynamics of siRNA biogenesis, transport, and silencing functions in the germ cells. This in-depth knowledge will also allow cell- and site-specific engineering of methylation for crop improvement.

小干扰RNA（siRNA）在调节生殖细胞功能中起重要作用。在开花植物中，21-22 nt的SiRNA与精子伴侣细胞（称为营养细胞）的运动有关，以沉默精子转座子。然而，非细胞自主信号的性质和沉默机制仍然存在争议。最近，我的宿主实验室发现，由性母细胞滋养细胞（称为绒毡层）产生的24-nt siRNA驱动拟南芥雄性生殖细胞中的DNA甲基化重编程，从而调节基因并抑制转座子。这些绒毡层siRNA足以形成精子中的整个从头甲基化组，然而，目前还不清楚这是如何实现的，因为绒毡层和sperm.My的初步工作之间的细胞质连接的情况下，有两个波的siRNA运输在种系发育过程中：第一波从绒毡层细胞到性母细胞，和第二波从营养细胞到精子。21-22和24 nt siRNA均被认为是通过与细胞特异性Argonaute蛋白相互作用而转运的，分别在转录后和转录基因沉默中发挥重要作用。使用细胞生物学，分子遗传学，单细胞型基因组学，表观遗传学和生物化学方法的组合，我将测试这些创新的假设，并通过调查阐明潜在的分子机制：目的1）siRNA在雄性生殖细胞中的生物合成和转运如何介导DNA甲基化，目的2）21-22 nt siRNA在雄性生殖细胞发育中的起源和功能，和目标3）细胞特异性Argonauts在生殖系siRNA途径中的中心作用。我的研究将通过揭示siRNA在生殖细胞中的生物发生、运输和沉默功能的复杂动态，为我们理解植物生殖系和遗传开辟新的视野。这种深入的知识也将允许甲基化的细胞和位点特异性工程用于作物改良。