Mammalian sperm-borne DNA binding proteins as reprogramming factors

如果普通细胞可以被诱导成任何指定的细胞类型，它们就可以用来修复患者有缺陷的组织；这是再生医学的愿景。大多数关于这种重新命名的工作使用的是人工培养的细胞，对它的了解仍然很少。我们建议一个补充的方法是看看大自然母亲如何在受精后实现重新命名。受精将两个独特的细胞——精子和卵子结合在一起，并将它们重新指定为一个细胞（单细胞胚胎），从而发育成一个完整的个体。这是重新命名的最戏剧性的例子，所以我们认为通过理解它，我们将了解所有其他的东西。目前，人们认为卵子是受精后重新命名过程中唯一活跃的参与者——精子被忽视了——但我们有证据表明精子也起着作用。本提案要求提供财政支助，以便在这一观察的基础上进一步发展，并确定所涉及的机制。这些机制的一个线索是，精子含有能够与遗传物质DNA结合的不寻常的蛋白质。这些蛋白质与精子头部的DNA没有紧密联系，因为它们是通过模拟卵子内部条件的温和处理释放的。我们建议的第一部分是制作一个完整的蛋白质列表，称为精子携带的DNA结合蛋白，或sbDBPs。然后，我们将仔细应用一系列方法，试图找出sbDBPs是否可以与卵子内的DNA结合。我们还想知道，如果我们在精子进入后立即干扰sbDBP的活性，可能是通过移除它，会发生什么。我们可以通过将精子和其他选定的分子一起注射到卵子中，然后观察卵子内部发生的情况来做到这一点。这些实验用的是老鼠，因为没有其他精子和卵子的来源，但如果这项工作成功了，它将改进替代方法，并提前动物研究过时的那一天。在缺席了10多年的国际研究经验之后，我们将把这些经验带到英国。我们希望利用这一经验，更好地了解精子在重新指定自身命运方面发挥的积极作用，以便更容易地重新指定其他细胞的命运，用于医疗应用，包括针对患者特定疾病的量身定制治疗。

If ordinary cells could be coaxed to become any designated cell type, they could be used to repair defective tissue in patients; this is a vision of regenerative medicine. Most work on this re-designation uses cells grown artificially and it is still poorly understood. We suggest that a complementary approach is to see how Mother Nature achieves re-designation after fertilisation. Fertilisation unites two unique cells - sperm and egg - and re-designates them to become one cell (a single-cell embryo) that can develop into an entire individual. This is the most dramatic example of re-designation, so we think that by understanding it, we will learn something about all the others.At present, it is assumed that the egg is the only active player in re-designation following fertilisation - the sperm is overlooked - but we have evidence that the sperm also plays a role. The present proposal requests financial support to build on this observation and determine the mechanisms involved.A clue to these mechanisms is that sperm contain unusual proteins able to bind to the genetic material, DNA. These proteins are not tightly associated with DNA in the sperm head, because they are released by gentle treatments that mimic conditions inside the egg. The first part of our proposal is to make a complete list of the proteins, termed sperm-borne DNA binding proteins , or sbDBPs.We will then carefully apply a range of approaches to try to find out whether sbDBPs can bind to DNA inside the egg. We would also like to know what happens if we interfere with sbDBP activity immediately after sperm entry, perhaps by removing it. We are able to do this by injecting sperm into eggs - together with other selected molecules - and watching what happens once inside. These experiments use mice, because there is no other source of sperm and eggs, but if the work is successful it will improve alternative methods and bring forward the day when animal research is obsolete.The laboratory is relocating to England after an absence representing over 10 years of international research experience which we will bring to the UK. We hope to use this experience to gain a better understanding of the active role sperm play in re-designating their own fate, so that it will be easier to re-designate the fates of other cells for medical applications, including tailor-made treatments of patient-specific diseases.