Progress in transcriptome analysis of spiral ganglion of cochlea

ELife online published a research paper titled "deep transcriptome analysis of spiral ganglion in multiple developmental nodes" by Liu Zhiyong, research group of brain science and brain like research center / Institute of neuroscience, Shanghai brain science and brain like research center, National Key Laboratory of neuroscience, Chinese Academy of Sciences The development and function of mouse and human auditory system are very similar The spiral ganglion of the cochlea is responsible for transmitting peripheral sound information (time, intensity, frequency, etc.) to the cochlear nucleus of the brain stem, and then to the auditory cortex through the superior olivary nucleus, inferior colliculus, thalamus and so on The function of spiral ganglion of cochlea is very important The therapeutic effect of cochlear implant on deaf patients depends largely on whether spiral ganglion of cochlea has function Therefore, how to maintain the function of spiral ganglion and how to regenerate functional spiral ganglion after injury is an important and challenging research direction in the field of hearing In order to find the starting point of the research, the research team first focused on two questions: 1) is the spiral ganglion of the cochlea specifically expressing some genes during the whole development process from early embryo to adult? 2) Are these specific genes characterized by dynamic changes, transient expression (regulating the development process), or permanent expression (maintaining the cell fate of the ganglia)? In order to accurately answer these two core questions, the team used transgenic mice to specifically express red fluorescent protein in spiral ganglion at five different developmental stages (e15.5, P1, P8, P14 and P30) Then, high purity and healthy spiral ganglion cells were obtained by tissue digestion and manual sorting Three replicates were analyzed at each time point Each replicate contained about 100 spiral ganglion cells This scheme can obtain a high-depth whole genome expression profile, which is 5 times the depth of the previous 10x single cell transcriptome analysis Based on this, this study analyzed many previously unknown genes with specific and dynamic changes in spiral ganglion expression In addition, the research team selected two specific genes, scrt2 and celf4, and constructed two gene knock-in models, scrt2-p2a-tdtomato and celf4-3xha-p2a-icreer-t2a-egfp, by using CRISPR / cas9 gene editing system, and carried out systematic analysis in the inner ear At the single cell level, the specific spiral ganglion of the cochlea was confirmed and highly expressed scrt2 and celf4, which further confirmed the transcriptome sequencing data in this paper Accuracy and reliability The new mouse model has important application value in the field of hearing and brain Neuroscience (scrt2 and celf4 genes are also highly expressed in the central system)