Construction Of Single-cell Chromatin Accessibility Landscape In Early Embryonic Development Of Danio Rerio

Zebrafish is a classic model organism,whose embryonic development process is short,transparent and easy to observe and manipulate,so it is often used in the research of embryonic development.Epigenetic regulation plays an important role in the development of zebrafish embryos.Epigenetic studies of zebrafish embryo development are of great significance for understanding the gene regulation mechanism during embryo development and the relationship between epigenetic regulation and human diseases.With the development of single-nucleus ATAC-seq technology and single-cell RNA-seq technology,we can analyze the spatial and temporal differentiation trajectory of zebrafish cells in the process of embryonic development from the dimension of single cells,and analyze the regulatory mechanism of different cell fate determination in the process of embryonic development through the difference analysis of gene expression and number changes of different cell groups.In addition,transcriptional regulation in zebrafish development involves many transcription factors and signaling pathways,and their mechanisms and regulatory networks need to be further studied.This research is based on the sequencing related technical expertise of the Shenzhen Huada Institute of Life Sciences.sn ATAC-seq and sc RNA-s were administered to the 7 key developmental time points of zebrafish embryos: high blastocyst period(3.3 h),50%epiblast period(5.25 h),shield period(6 h),tail bud period(10 h),6 somatic period(12 h),20 somatic period(18 h)and primordium-5 period(24 h)to detection,we conducted a comprehensive analysis of chromatin opening and gene expression at these 7 time points,and screened cis-elements specifically regulated during the development of zebrafish embryos and their biological functions from the developmental time dimension and cell dimension respectively.To identify trends of chromatin opening over developmental time to further understand the functional changes that occur under these opening trends.The cell specific motifs enriched in different cell types were found and the transcription factors binding to them were analyzed.Finally,the regulation of transcription factor nr5a2 and its target genes was analyzed in detail by analyzing the apparent changes of the muscular system during embryonic development,so further explore the regulatory mechanism of transcription factor nr5a2 at different developmental stages.Based on the above analysis results,we constructed a landscape of single-cell chromatin accessibility in early embryonic development of zebrafish,analyzed the dynamic changes in chromatin accessibility during this process,and described the cell type-specific cis-regulatory network.By analyzing the single-cell chromatin accessibility of the muscle system during the development of zebrafish embryos,the dynamic changes of the regulatory network of transcription factor nr5a2 during muscle development were systematically explored.In subsequent studies,the reliability of the conclusion can be strengthened by further detection of zebrafish embryo tissue slices.From the perspective of chromatin accessibility and epigenetics,we screened the key transcription factors in the development of zebrafish embryos,and comprehensively analyzed their biological functions and upstream and downstream regulatory mechanisms.These findings not only deepen our understanding of the molecular mechanism of cell fate determination in zebrafish development,but also provide new ideas and directions for the prevention and treatment of related diseases.