Stem cell regulation in the wasp Copidosoma floridanum

描述(申请人提供)：干细胞自我更新和分化为其他细胞类型的能力使它们成为生命科学家非常感兴趣的主题。生殖系干细胞是一类干细胞，只产生与生殖系相关的细胞，包括卵子和精子，因此在发育方面也很重要。生殖系干细胞在历史上被证明是具有挑战性的，因为它们在生物体中很稀缺。花冠冠蜂(Copidosoma Floridanum)是一种寄生的多胚胎黄蜂，是一种很有前途的研究生殖系STAR细胞调控的生物体，因为a)它们产生相对丰富的生殖系干细胞及其前体细胞；b)它们有两个与生殖系调控变化相关的显著发育过程。首先，华氏梭子藻是多胚胎的，这意味着成千上万的后代从一个卵子克隆发育而来，因此成千上万的生殖系干细胞也是如此。多胚性在一定程度上是通过在胚胎发育早期增加增殖来实现的。其次，同一世代的后代发育成形态不同的幼虫种姓。最近的证据表明，生殖质是决定生殖系干细胞前体的细胞质，对于这两个过程都是必需的。去除华丽锦鸡儿中含有细胞的种质会减少繁殖，并消除生殖种姓的分化。在这里，我假设早期干细胞调控的变化是导致该物种多胚胎和种姓分化的原因。这项建议的具体目的是通过结合观察性研究和功能研究来测试关于含有细胞的生殖质在发育过程中应该如何发挥作用的明确预测，以评估我的假设。我这项研究的长期目标是了解生殖系和其他干细胞在发育过程中的功能。虽然生殖系干细胞对发育至关重要，并与疾病有关，但人们对它们是如何形成的知之甚少。这项工作将有助于理解干细胞的分子控制以及它们在不同生物体之间的差异。

DESCRIPTION (provided by applicant): The capacity of stem cells to self renew and differentiate into additional cell types has made them a subject of great interest to life scientists. Germline stem cells are a category of stem cells that give rise only to cells associated with the germline, including egg and sperm, and thus are also important for developmental reasons. Germline stem cells have historically proven challenging to study because of their scarcity in organisms. Copidosoma floridanum, a parasitic, polyembryonic wasp, is a promising organism in which to study germline stern cell regulation because a) they produce germline stem cells and their progenitors in relative abundance and b) they have two striking developmental processes associated with changes in germline regulation. First C. floridanum is polyembryonic meaning that thousands of offspring develop clonally from a single egg and therefore so too do thousands of germline stem cells. Polyembryony is achieved, in part, by increased proliferation early in embryogenesis. Secondly, offspring of the same brood develop into morphologically distinct larval castes. Recent evidence indicates that germ plasm, the cytoplasm defining germline stem cell precursors, is required for both of these processes. Ablation of germ plasm containing cells in C. floridanum decreases proliferation and eliminates differentiation of the reproductive caste. Here, I hypothesize that changes in early stem cell regulation are responsible for polyembryony and caste differentiation in this species. The specific aims of this proposal are to evaluate my hypothesis by testing explicit predictions about how germ plasm containing cells should act during development using a combination of observational and functional studies. The long-term goals of my study are to understand the function of germline and other stem cells during development. While germline stem cells are essential for development and have been linked to disease, very little is understood about how they are formed. This work will contribute to understanding the molecular controls of stem cells and how they vary among organisms.