Integrative mRNA and miRNA Expression Profiles from Developing Zebrafish Head Highlight Brain-Preference Genes and Regulatory Networks.

Zebrafish is an emerging animal model for studying molecular mechanism underlying neurodevelopmental disorder due to its advantage characters. miRNAs are small non-coding RNAs that play a key role in brain development. Understanding of dynamic transcriptional and post-transcriptional molecules and their regulation during the head development is important for the study of neurodevelopmental disorder. In this study, we performed the high-throughput sequencing of mRNAs and miRNAs in developing zebrafish head from pharyngula to early larval stages and carried out bioinformatic analysis including differential expression and functional enrichment as well as joint analysis of miRNAs and mRNAs, and also compared with other related public sequencing datasets to aid our interpretation. A large number of differential expression genes with a large fold change were detected during the head development. Further clustering and functional enrichment analyses indicated that genes in late stage were most related with synaptic signaling. Overlap test analysis showed a significant enrichment of brain-preference and synapse-associated gene set in the head transcriptome compared with the whole embryo transcriptome. We also constructed miRNA-mRNA network for those brain-preference genes and focused on those densely connected network components. CRISPR-Cas9-mediated snap25b mutants led to embryonic development defects and decreases locomotor activity. Altogether, the present study provides developmental profiles of head-enriched mRNAs and miRNAs at three critical windows for nervous system development, which may contribute to the study of neurodevelopmental disorder.