Muscle Developmental Defects in Heterogeneous Nuclear Ribonucleoprotein A1 Knockout Mice. Mus musculus

Transcriptome analysis of total RNA samples from heart tissue of knockout mice Alternative splicing is the main mechanism to increase protein diversity from an mRNA. Heterogeneous ribonucleoprotein (hnRNP) family members are vital regulators of alternative splicing. The hnRNP A1 is the most well-known protein in this family, but its role in embryonic development is not well understood. We generated hnRNP A1 knockout mice to study the function of hnRNP A1 in vivo. The hnRNP A1-depleted mice showed embryonic lethality because of muscle developmental defects. In a previous study, cellular hnRNP A2/B1 was reported to be capable of compensating for the expression of hnRNP A1. However, this phenomenon did not occur in the hnRNP A1 heterozygous mice in vivo. We demonstrated that hnRNP A1 regulated muscle-related genes expression and alternative splicing. In summary, our data demonstrated that hnRNP A1 plays a critical role in embryonic muscle development. Understanding the effects of hnRNP A1 in vivo may help to define the function of hnRNP A1 in alternative splicing. Overall design: We analyzed total RNA from heart of knockout mice (3 males) using the Affymetrix Mouse Exon 1.0 ST platform. Array data was processed by Affymetrix Exon Array Computational Tool. No techinical replicates were performed.

针对敲除小鼠心脏组织总RNA样本的转录组学分析：可变剪接（alternative splicing）是信使RNA（messenger RNA, mRNA）扩增蛋白质多样性的核心机制。异质性核糖核蛋白（heterogeneous ribonucleoprotein, hnRNP）家族成员是可变剪接的关键调控因子。hnRNP A1是该家族中研究最为广泛的蛋白，但其在胚胎发育中的功能尚未完全阐明。为在体内解析hnRNP A1的生物学功能，我们构建了hnRNP A1敲除小鼠模型。hnRNP A1缺失的小鼠会因肌肉发育缺陷出现胚胎致死表型。既往研究表明，细胞内的hnRNP A2/B1可代偿hnRNP A1的表达功能，但该代偿现象并未在体内的hnRNP A1杂合子小鼠中出现。本研究证实，hnRNP A1可调控肌肉相关基因的表达与可变剪接事件。综上，本研究数据表明hnRNP A1在胚胎肌肉发育过程中发挥关键调控作用。阐明hnRNP A1在体内的生物学效应，有助于明确其在可变剪接调控中的功能。实验整体设计：本研究采用Affymetrix小鼠外显子1.0 ST芯片平台，对3只雄性敲除小鼠的心脏总RNA进行转录组分析。芯片数据通过Affymetrix外显子芯片分析工具完成预处理。本实验未设置技术重复样本。