Differential analysis of chromatin accessibility and histone modifications for predicting mouse developmental enhancers

Enhancers are distal cis-regulatory elements that modulate gene expression. They are depleted of nucleosomes and enriched in specific histone modifications; thus, calling DNase-seq and histone mark ChIP-seq peaks can predict enhancers. We evaluated nine peak-calling algorithms for predicting enhancers validated by transgenic mouse assays. DNase and H3K27ac peaks were consistently more predictive than H3K4me1/2/3 and H3K9ac peaks. DFilter and Hotspot2 were the best DNase peak callers, while HOMER, MUSIC, MACS2, DFilter and F-seq were the best H3K27ac peak callers. We observed that the differential DNase or H3K27ac signals between two distant tissues increased the area under the precision-recall curve (PR-AUC) of DNase peaks by 17.5-166.7% and that of H3K27ac peaks by 7.1-22.2%. We further improved this differential signal method using multiple contrast tissues. Evaluated using a blind test, the differential H3K27ac signal method substantially improved PR-AUC from 0.48 to 0.75 for predicting heart enhancers. We further validated our approach using postnatal retina and cerebral cortex enhancers identified by massively parallel reporter assays, and observed improvements for both tissues. In summary, we compared nine peak callers and devised a superior method for predicting tissue-specific mouse developmental enhancers by reranking the called peaks

hub

hub file</p

atac-seq arpe ucsc track

atac arpe ucsc genome tracks for inter3D</p

Inter3d

TAD (Topologically Associating Domain) reorganization occurs commonly in cell nucleus and contributes to gene activation and inhibition through separation or fusion of adjacent TADs. However, identification of functional genes impacted by TAD alteration and revealing of TAD- reorganization mechanism underlying gene transcription remain to be fully elucidated. Here, we firstly developed a novel approach termed Inter3D to specifically dig out genes regulated by TAD reorganization. By constructing the comprehensive TAD reorganization medicating epigenomic landscapes in tumor cells, we showed that TAD separation interrupted the intrachromosomal loop at MYL12B locus and abrogated its transcription, while TAD fusion generated the chromosomal interaction and triggered CYP27B1 activation. Our study provides a comprehensive insight into capture of TAD rearrangement-mediated gene loci and moves towards recognizing the functional role of TAD reorganization in gene transcription.</p

trackDb

trackdb file for inter3d</p

arpe hic files

arpe hic genome files</p

weri atac-seq

weri atac-seq for inter3d project</p

genome

genome file</p

weri hic files

weri hic genome files</p

Deep Surveying of the Transcriptional and Alternative Splicing Signatures for Decidual CD8+ T Cells at the First Trimester of Human Healthy Pregnancy

Decidual CD8+ (dCD8) T cells have been proposed to play important roles in immune protection against the invading pathogens and in tolerance toward the growing semi-allogeneic fetus during early pregnancy. However, their phenotypic and functional characteristics remain poorly defined. Here, we performed the first analysis of the transcriptional and alternative splicing (AS) signatures for human first-trimester dCD8 T cells using high-throughput mRNA sequencing. Our data revealed that dCD8 T cells have distinct transcriptional and AS landscapes when compared with their autologous peripheral blood CD8+ (pCD8) T counterparts. Furthermore, human dCD8 T cells were observed to contain CD8-Treg and effector-memory T-cell subsets, and display enhanced functionality in terms of degranulation and cytokine production on a per-cell basis. Additionally, we have identified the novel splice junctions that use a high ratio of the non-canonical splicing motif GC-AG and found that AS is not a major contributor to the gene expression-level changes between paired pCD8 and dCD8 T cells. Together, our findings not only provide a comprehensive framework of the transcriptional and AS landscapes but also reveal the functional feature of human dCD8 T cells, which are of great importance in understanding the biology of these cells and the physiology of human healthy pregnancy