Journal of Brain Research

WGCNA Analysis of Gene Expression Difference between Afferent and Efferent Nerves in Mice during Development

Abstract

Yi Zhang*, Koon Hei Winson Lui, Guanggeng Wu, Tianjiao Zhao, Di Wen, Peiwen Bai, Yangbin Xu and Xiangxia Liu

The efferent (motor) and afferent (sensory) nerves may appear physically similar in structure, however with closer inspection, numerous differences could be observed in terms of cellular composition, extracellular matrix or structure. To investigate the reason for the differences, study was conducted on the gene expression of the afferent and efferent nerve fibers during the stage of growth and development. Analysis was conducted on the afferent and efferent nerve chip data of the mice (data coded GSE113820) from the GEO database. This set of data contained information derived from the nervous tissue of C57BL/6 mice. To reduce statistical bias, Weighted Gene Co-Expression Network Analysis (WGCNA) was used for the analysis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed in specific modules obtained after WGCNA analysis and the interaction network was constructed. It was found DEmRNAs in the PURPLE module were down regulated as the time of development progresses in the efferent nerves, in comparison there were only minor down regulation of the same DEmRNAs in the afferent nerves. These DEmRNAs were located in the postsynaptic membrane, cytoplasm and mitochondria, responsible for the function of anterograde transport of neurotransmitters and inhibition of apoptosis. The Kcna6 and Agpat4 were found to be the Hub gene of PURPLE module. These genes may play an important role during development in maintaining the function of sensory and motor nerves. WGCNA could be a useful tool that could help find different gene expressions in different types of nerves during development.