杂交小鼠中等位基因特异RNA可变剪接调控的多组织全基因组研究

Alternative splicing (AS), one of the most important post-transcriptional regulatory mechanisms, plays a critical role in pathophysiological processes. The precise spatial-temporal control of alternative splicing is achieved via the interaction between the cis-elements located within the primary RNA transcripts and trans-factors, mostly RNA-binding proteins with regulatory functions. The global dissection of AS regulatory network could start from the systematic identification of functional cis-elements, for which currently the most efficient strategy is to analyze the allele-specific pattern in a F1 hybrid system. In this proposal, we take advantage of the F1 hybrid mice between C57BL/6J and SPRET/EiJ, the two strains with the largest genome divergence among all pairs of the inbred mouse strains with available genome references, and for the first time measure the allele-specific AS patterns across different tissues/cells. Based on these patterns, we will discover novel cis-elements and accompanying trans-factors， thereafter reconstructing the AS regulatory networks functioning in distinct tissues/cells. Finally, our findings of the regulatory networks will be used to analyze cancer genome sequencing data and screen for the mutations with impacts in AS deregulation. The results will facilitate the further understanding of the role of AS in the tumoriogenesis and pave the way for the future development of precision medicine in treating cancer patients.

mRNA可变剪接是调节基因表达的重要机制，在控制诸多生理进程和多种疾病发生发展中起着决定性的作用。可变剪接时空上的精确调控主要依赖于mRNA前体上的顺式元件和反式作用因子之间的相互作用。系统研究可变剪接调控网络可以从顺式调控元件的全面鉴定开始，而目前通过研究模式生物杂交子一代中等位基因特异的基因调控模式是研究基因调控顺式元件最为有效的策略。本项目将基于独特的具有最大化的亲本基因组序列差异的C57BL/6J和SPRET/EiJ杂交小鼠模型，首次全面系统地研究等位基因特异的可变剪接模式的跨组织分布。在获得的等位基因特异的可变剪接模式基础上，我们将全面鉴定顺式调控元件和相应反式作用因子，并重构不同组织的可变剪接调控网络。最后我们将发现的调控网络用于筛选在肿瘤发生发展中导致可变剪接失调的功能性突变， 为进一步了解可变剪接失调在肿瘤发生发展中所起作用打下基础，推动肿瘤精准诊断及治疗进一步发展。

mRNA可变剪接是调节基因表达的重要机制，在控制诸多生理进程和多种疾病发生发展 中起着决定性的作用。可变剪接时空上的精确调控主要依赖于mRNA前体上的顺式元件和反式作用因子之间的相互作用。系统研究可变剪接调控网络可以从顺式调控元件的全面鉴定开始，而目前通过研究模式生物杂交子一代中等位基因特异的基因调控模式是研究基因调控顺式元件最为有效的策略。本项目基于独特的具有最大化的亲本基因组序列差异的C57BL/6J和SPRET/EiJ杂交小鼠模型，首次全面系统地研究了等位基因特异的可变剪接模式的跨组织分布。在获得的多组织中等位基因特异的可变剪接模式基础上，我们细致分析挖掘了等位基因特异可变剪接的演化模式和跨组织调控机制，并通过实验方式验证了反式调控因子水平对顺式调控元件的“缓冲作用”。最后我们在小头畸形患者中鉴定一个影响可变剪接的功能性突变。我们的研究结果进一步了解可变剪接在该疾病中的功能，推动精准医疗的发展。