Yolk protein-mediated germline delivery in vector snails

摘要 基于遗传学的媒介控制在抗击媒介传播疾病方面大有可为。这样一个有希望的 然而，该策略尚未在任何血吸虫病媒介钉螺控制方案中得到测试，血吸虫病是 世界上最具破坏性的寄生虫病。关键原因是缺乏生殖系递送技术 将遗传物质输送到配子或胚胎中。无法将遗传物质输送到蜗牛体内 生殖细胞是由于其配子的复杂解剖结构，其卵子非常小， 及其不同寻常的生殖系统，这排除了所有现有的、发育良好的基因的应用 交付技术。为了绕过这些限制，我们提出了一种利用蜗牛的创新方法 卵黄蛋白作为载体，通过受体的自然过程将遗传物质运送到正在发育的卵母细胞中 卵黄发生过程中介导的内吞作用。两种最有前景的蜗牛卵黄蛋白--卵黄铁蛋白 和卵黄蛋白原，这两种蛋白都存在于血吸虫病媒介光滑蜗牛的基因组中， 将会被调查。我们将首先从蜗牛卵黄铁蛋白中鉴定出一个高效的卵母细胞受体结合配体 或卵黄蛋白原(Aim1)，然后测试已鉴定的配体在传递簇状规则间隔短 回文重复序列(CRISPR)进入卵母细胞进行胚系修饰(目标2)。这项研究将开启一项 为血吸虫病基础和应用研究的所有基因操作研究打开激动人心的大门。

SUMMARY Genetics-based vector control holds great promise in combating vector transmitted diseases. Such a promising strategy, however, has not yet been tested in any vector snail control program of schistosomiasis, one of the world’s most devastating parasitic diseases. The key reason is the lack of a germline delivery technology for delivering genetic materials into gametes or embryos. The inability to deliver genetic materials into snail germline cells is due to the complex anatomical structure of its gametes, the exceedingly small size of its eggs, and its unusual reproductive system, which preclude the application of all existing, well-developed genetic delivery technologies. To circumvent these limitations, we propose an innovative approach that exploits snail yolk proteins as vehicles for shuttling genetic materials into growing oocytes via the natural process of receptor- mediated endocytosis during vitellogenesis. Two types of the most promising snail yolk proteins, yolk ferritin and vitellogenin, both found present in the genome of the schistosomiasis vector snail Biomphalaria glabrata, will be investigated. We will first identify a highly efficient oocyte receptor-binding ligand from snail yolk ferritin or vitellogenin (Aim1) and then test the identified ligand in delivering clustered regularly interspaced short palindromic repeats (CRISPR) cargo into the oocytes for germline modification (Aim 2). This study will open an exciting door for all genetic manipulation studies for basic and applied research of schistosomiasis.