Systematic characterization of gene regulatory interactions with high-throughput CRISPR screens

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Abstract/Contents

Abstract
Chapter 1: Hundreds of thousands of cis-regulatory elements (CREs) have been identified across a myriad of cell types and conditions, but relatively few have been empirically characterized. Here, we present a scalable, phenotype-driven CRISPR screen to identify hundreds of essential regulatory elements in K562 cells by perturbing 7,500 DNase hypersensitive sites (DHS) around the top 400 essential genes in K562. In addition to distal enhancers, we identify promoter-overlapping enhancers that selectively regulate multiple genes. Using orthogonal CRISPR systems with narrow or broad perturbative windows, we demonstrate that fine-mapping screens can resolve and characterize core transcription factor binding sites (TFBSs) within enhancers, highlighting the advantages of complementary CRISPR systems to investigate CREs. Lastly, we use our results to further interrogate how transcription factor binding sites hierarchically interact to drive enhancer function at the CBFA2T3 locus. This study demonstrates a scalable CRISPR screening framework for identifying and dissecting CREs that regulate selectable phenotypes. Chapter 2: The ENCODE consortium's encyclopaedia, containing millions of non-coding CREs has advanced our understanding of gene regulatory landscapes. Nonetheless, few CREs have been functionally characterized directly; determining the regulatory effects on gene expression is a critical next step, and pooled, non-coding CRISPR screens have emerged as a valuable tool to endogenously characterize the function of CREs. However, these screens' design, execution, and analysis have been highly heterogeneous. Here, we present the ENCODE CRISPR screen database: the largest, multi-center, standardized collection of non-coding screens to date. We evaluated the most common design and analysis platforms and observed that functional elements are enriched at DHS/H3K27ac sites, while the strongest sgRNAs target the DHS summit. Additionally, we discovered a subtle, previously undescribed target DNA strand-bias for CRISPRi in transcribed regions. Our dataset represents a broad resource for the community, establishes a standardized data format, provides guidelines for screen implementation, and uncovers fundamental insights into gene regulation.

Description

Type of resource text
Form electronic resource; remote; computer; online resource
Extent 1 online resource.
Place California
Place [Stanford, California]
Publisher [Stanford University]
Copyright date 2023; ©2023
Publication date 2023; 2023
Issuance monographic
Language English

Creators/Contributors

Author Yao, David
Degree supervisor Bassik, Michael
Thesis advisor Bassik, Michael
Thesis advisor Engreitz, Jesse
Thesis advisor Greenleaf, William James
Thesis advisor Kundaje, Anshul, 1980-
Degree committee member Engreitz, Jesse
Degree committee member Greenleaf, William James
Degree committee member Kundaje, Anshul, 1980-
Associated with Stanford University, School of Medicine
Associated with Stanford University, Department of Genetics

Subjects

Genre Theses
Genre Text

Bibliographic information

Statement of responsibility David Yao.
Note Submitted to the Department of Genetics.
Thesis Thesis Ph.D. Stanford University 2023.
Location https://purl.stanford.edu/vk828vb5651

Access conditions

Copyright
© 2023 by David Yao
License
This work is licensed under a Creative Commons Attribution 3.0 Unported license (CC BY).

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