# Death-Seq, a Method for Genome-wide Identification of Functional Silencer Elements

> **NIH NIH R21** · CINCINNATI CHILDRENS HOSP MED CTR · 2020 · $159,000

## Abstract

Title: Death-Seq, a Method for Genome-wide Identification of Functional Silencer
Elements
Summary
The human genome contains an estimated 98.5% of non-coding DNA 1. Little is known about the function of this
non-coding DNA, and limited tools are available to assay for functional non-coding regions. These non-coding
regions contain essential regulatory elements (e.g., enhancers, silencers, insulators) that are paramount during
normal human development and whose dysregulation is implicated in numerous human diseases. Mapping
regulatory elements in our genome currently relies upon structural assays, location of transcription factor
binding sites or chromatin marks and a few functional assays, including STARR-Seq (a self-transcribing reporter
assay to measure enhancer functionality). Despite increasing knowledge of the function and location of
enhancers, no tool exists to functionally assay silencer elements.
We propose a novel method, termed Death-Seq, to interrogate genome-wide DNA for functional silencer ability
by negative selection. Briefly, genomic libraries for interrogation will regulate expression of a suicide gene within
a transfectable vector. Under the control of an enhancer element, the suicide gene will express and induce cell
death, leading to vector depletion. A silencer element will repress suicide gene expression, leading to cell (and
vector) survival. After selection, plasmids from the surviving cells will be sequenced and are expected to contain
only functional silencer elements. Aim 1 proposes to identify constitutive silencers using a Caspase 9- based
suicide gene to induce apoptosis. Aim 2 describes a variation the approach, allowing for silencer interrogation at
user-defined timepoints (for detection of silencers dependent on inducible repressors). This tool addresses an
unmet need in the gene regulation community, as no current technique allows for genome-wide study of silencer
function. Additionally, Death-Seq may be used in future investigations to test diverse hypotheses; its versatility
allows for interrogation of varied input libraries (e.g., genomic or ATAC/ChIP-Seq), and its transfectability
allows for study of silencers in diverse cell types.
Death-Seq will allow for the cataloguing of genomic silencer elements, both cell-type specific and universal. The
location of a functional silencer will enhance understanding of transcriptional and chromatin regulation by
transcription factors. Identifying novel silencer motifs, as well as genome-wide characteristics of silencer
locations, will benefit the community of genomic research broadly. Identifying silencer element locations in non-
coding results of genome-wide association studies (GWAS) will yield directions for future rational research into
the mechanisms of human disease. We believe that the tool developed through this proposal, Death-Seq, will
provide an innovative yet feasible solution to investigating silencer biology.

## Key facts

- **NIH application ID:** 9979291
- **Project number:** 1R21GM135634-01A1
- **Recipient organization:** CINCINNATI CHILDRENS HOSP MED CTR
- **Principal Investigator:** Artem Barski
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $159,000
- **Award type:** 1
- **Project period:** 2020-06-01 → 2022-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9979291

## Citation

> US National Institutes of Health, RePORTER application 9979291, Death-Seq, a Method for Genome-wide Identification of Functional Silencer Elements (1R21GM135634-01A1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9979291. Licensed CC0.

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