Development of conditional and inducible gene targeting tools in rabbits

项目摘要 实验动物模型在人类疾病研究中发挥着重要作用。使用适当的动物是 不仅对基础研究至关重要，而且对治疗学和诊断工具的发展也至关重要。兔子 是一种经典的实验动物物种。 通过使可编程核酸酶，如CRISPR/Cas9，适应于基因打靶平台，我们最近 在兔体内实现了高效的基因敲除和敲入。人们认识到诱导性和条件性基因 仍然缺乏安全港轨迹、Cre-loxP和Tet等靶向工具，这成为限制因素 这一重要的大型动物模型系统在生物医学研究中具有广泛的适用性。 我们先前鉴定了兔子rosa26基因座，证明它可以作为一个安全的避风港基因座， 并生产ROSA26-EGFP兔。我们还发现了另一个假定的安全港基因，直射同源基因 Hipp11(H11)，位于兔基因组第21号染色体上。 在本项目中，我们建议：(I)培育条件性基因敲除(CKO)兔；(Ii)培育诱导型 击倒(IKO)兔。为了达到CKO和IKO的目标，我们将利用兔的H11(RbH11)基因座作为 为下井作业提供第二个安全避难所，并开发CRE-loxP、Creer-loxP和Tet ON/OFF工具。 此外，我们还建议开发基于CAS9的CKO/IKO工具。 通过拟议的工作，我们将生成多种工具来实现条件性和诱导性的基因靶向 兔子身上的工具。这些工具将实现对该模式物种基因表达的空间和时间控制。

Project Summary Laboratory animal models play an important role in the study of human diseases. Using appropriate animals is critical not only for basic research but also for the development of therapeutics and diagnostic tools. The rabbit is a classical experimental animal species. By adapting the programmable nucleases, such as CRISPR/Cas9, to the gene targeting platform, we recently achieved efficient gene knockout and knock-in in rabbits. It is realized that inducible and conditional gene targeting tools, such as safe harbor locus, Cre-loxP, and Tet, are still lacking which becomes a limiting factor for the broad applicability of this important large animal model system in biomedical research. We previously characterized the rabbit Rosa26 locus, demonstrated that it can be used as a safe harbor locus, and produce Rosa26-EGFP loxed rabbits. We have also identified another putative safe harbor locus, ortholog of Hipp11 (H11), on Chromosome 21 in the rabbit genome. In the present project we propose to: (i) develop conditional knockout (cKO) rabbits; and (ii) develop inducible knockout (iKO) rabbits. To achieve the cKO and iKO goals, we will utilize the rabbit H11 (rbH11) locus as the second safe harbor locus for knock-in work, and to develop Cre-loxP, CreER-loxP and Tet on/off tools. Furthermore, we propose to develop Cas9 based cKO/iKO tools. Through the propose work, we will generate versatile tools to enable conditional and inducible gene targeting tools in rabbits. These tools will realize spatial and temporal control of gene expressions in this model species.