Role of phosphorylated Gonadotropin-Regulated Testicular RNA Helicase (GRTH/DDX25) in the Regulation of Germ Cell Specific mRNAs in Chromatoid Bodies during Spermatogenesis

In this study, we examined transcriptome profiles of Chromatoid bodies (organelle; CB) of germ cells isolated from GRTH Knock-In (Human GRTH gene with R242H mutation) and WT mice testis using RNA-Seq. We used homozygous GRTH KI mice (which show loss of phospho-GRTH) to further understand the importance of CB and phospho-GRTH and their role in spermatid development during spermiogenesis by analyzing the DEGs from RNA-Seq. The analysis of RNA-Seq data allowed us to find the relevant DEGs related to RNA Transport and Protein processing that are essential for spermatid development. This study using KI mice model demonstrated that loss of phospho-GRTH impairs CB structure and mRNA storage function (in CB) and chromatin compaction hampering initial stages of spermatid elongation process. Transcriptome profiles of Chromatoid bodies (organelle; CB) in germ cells of WT and GRTH-Knock-In mice by Illumina RNA-Seq for gene expression profiling.本研究采用RNA测序（RNA-Seq）技术，对分离自GRTH敲入（GRTH Knock-In，携带R242H突变的人源GRTH基因）及野生型（Wild Type, WT）小鼠睾丸的生殖细胞拟染色体体（Chromatoid bodies, CB，细胞器）的转录组谱展开分析。我们选用纯合子GRTH敲入小鼠——该模型可呈现磷酸化GRTH缺失表型——通过分析RNA测序所得的差异表达基因（Differentially Expressed Genes, DEGs），进一步探究拟染色体体与磷酸化GRTH的生物学功能，及其在精子形成过程中对精子细胞发育的调控机制。对RNA测序数据的分析结果显示，我们找到了与RNA转运及蛋白质加工相关的关键差异表达基因，而这些过程对于精子细胞发育至关重要。本研究借助敲入小鼠模型证实，磷酸化GRTH的缺失会损伤拟染色体体的结构及其mRNA储存功能，同时破坏染色质浓缩过程，进而阻碍精子细胞伸长的初始阶段。本研究采用Illumina RNA测序技术，对野生型与GRTH敲入小鼠生殖细胞内的拟染色体体转录组谱进行基因表达谱分析。