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INT-Hi-C reveals distinct chromatin architecture in endosperm and leaf tissues of Arabidopsis.

ABSTRACT: Higher-order chromatin structure undergoes striking changes in response to various developmental and environmental signals, causing distinct cell types to adopt specific chromatin organization. High throughput chromatin conformation capture (Hi-C) allows studying higher-order chromatin structure; however, this technique requires substantial amounts of starting material, which has limited the establishment of cell type-specific higher-order chromatin structure in plants. To overcome this limitation, we established a protocol that is applicable to a limited amount of nuclei by combining the INTACT (isolation of nuclei tagged in specific cell types) method and Hi-C (INT-Hi-C). Using this INT-Hi-C protocol, we generated Hi-C data from INTACT purified endosperm and leaf nuclei. Our INT-Hi-C data from leaf accurately reiterated chromatin interaction patterns derived from conventional leaf Hi-C data. We found that the higher-order chromatin organization of mixed leaf tissues and endosperm differs and that DNA methylation and repressive histone marks positively correlate with the chromatin compaction level. We furthermore found that self-looped interacting genes have increased expression in leaves and endosperm and that interacting intergenic regions negatively impact on gene expression in the endosperm. Last, we identified several imprinted genes involved in long-range and trans interactions exclusively in endosperm. Our study provides evidence that the endosperm adopts a distinct higher-order chromatin structure that differs from other cell types in plants and that chromatin interactions influence transcriptional activity.

SUBMITTER: Yadav VK

PROVIDER: S-EPMC8096224 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Modified Hi-C reveals distinct chromatin architecture in endosperm and leaf of Arabidopsis

Project description:Higher-order chromatin structure undergoes dramatic changes in response to various developmental and environmental signals, wherein distinct cell types posses specific chromatin organization. High throughput chromatin conformation capture assays (Hi-C) allows study of higher-order chromatin structure; however, it requires a large number of cells. This requirement has so far limited the establishment of cell type-specific higher-order chromatin structure in the plant. To overcome this limitation, we modified the Hi-C protocol (mHi-C) to be applicable to a limited amount of starting material. For this, mHi-C libraries were generated from INTACT-purified endosperm and leaf nuclei. Correlation plots showed that our mHi-C data from INTACT-leaf accurately reiterate chromatin interaction patterns derived from conventional leaf Hi-C data. We further identified compacted structural domains (CSDs) and loose structural domains (LSDs) in leaf and endosperm and their differential patterns revealed distinct higher-order chromatin organization in leaf and endosperm. Our analysis revealed that DNA methylation and repressive histone marks positively correlate with the chromatin compaction level. We discovered increased chromatin interactions frequencies in the endosperm in comparison to leaf tissue. Using cell-specific Hi-C and INTACT-RNA-seq, on a genome-wide scale higher expression of self-looped interacting genes was observed. It was further identified that interacting intergenic regions act as a negative regulator and influence the gene expression in a specific cells in the plant. Our study provides evidence that the higher-order chromatin structure differs between cell types in plants and these interactions could influence the transcription activity positively as well as negatively.

2021-03-04 | GSE145769 | GEO

Modified Hi-C reveals distinct chromatin architecture in endosperm and leaf of Arabidopsis

Project description:Modified Hi-C reveals distinct chromatin architecture in endosperm and leaf of Arabidopsis

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