Research Of Chromatin Accessibility Of Cell Fate Decisions During Early Embryogenesis

Cell lineages that form different tissues or cells have been studied extensively during embryonic development,but the common features of underlying gene-regulatory-networks(GRNs)in mammals,plants,and fungi and the epigenetic changes driving cell fate transition are only partially delineated.Understanding how the cell fate decision has chosen is a fascinating biological question that was received consider attention over the last decade.With the deepening of genomic research,the important role of non-coding regions of eukaryotic genomes in transcriptional regulation is constantly revealed.The non-coding regulatory regions of eukaryotic account of about 97% of the whole genome.There are many regulatory elements such as promoters,enhancers,and silencers.These regulatory elements not only have important biological functions,but also are closely related with many important diseases.In the non-coding regions of eukaryotes,a part of transcription factors(TFs)binding regions and TFs constitute a complex transcriptional regulation system of eukaryotes,which has been a research hotspot in recent years.Numerous TFs are required,and many have been shown to have essential roles in cellfate determination.The development of multi-cellular organisms begins from a single-celled zygote,which undergoes rapid cell division and development.After an egg is fertilized,and has fused with sperm to form a zygote,an embryo begins to develop.The process in which an organism develops from zygote to a multi-cellular organism is complex and well-regulated,which are regulated by multiple TFs and gene complexes.The early stages of embryonic development are also crucial for ensuring the fitness of the organism.In this study,we selected six representative species,including human,mouse,Drosophila,C.elegans,Arabidopsis,S.cerevisiae,comparing the difference of transcriptional regulatory mechanisms of cell fate decisions in different species.Here,we made a comprehensively joint research of chromatin changes of human,mouse,Drosophila,C.elegans,Arabidopsis,S.cerevisiae(nuclear cycle)during early embryonic development using ATAC-seq(Assay for Transposase Accessible Chromatin with high-throughput sequencing)datasets.By leveraging on dynamics changes of chromatin accessibility and early embryonic transcriptome,we identified sets of cell-fate-determined TFs that involved in early embryogenesis.Reconstruction of regulatory circuits of early embryonic cell fate decision reveal that many TFs that control early embryo cell fate homolog to cell fate TFs in other species,which control different cell fate.For example,in Drosophila,the circuitry of lz-Med-Mad-pnr-toy-tll-zen controls the eye development,prd,fkh,pnr,and pan are indispensable for gland cell fate determination,and su(Hw),ac,Su(H),Kr,tll,D,pnr,pnt,and gcm promote nerve system development.hlh-2,pha-4,elt-1,hlh-1,and pal-1 are critical for epidermis cell fates in C.elegans.In Arabidopsis,JKD,GL2,GL3,and EGL3 form a circuit to control the patterns of root epidermis,HAT2,HAT3,BZR1,and BIM1 promote seedling development,and KAN,PHB,PHV,and BIM1 form a regulatory complex to promote leaf development and determine leaf adaxial polarity.And RIM101,FKH1,FKH2,MSN2,MSN4,ABF2,DAL80,and CBF1 are involved in stress responses in S.cerevisiae.Our research provides an intriguing insight into evolution of cell fate decision during early embryogenesis across different species.