# Identification of stage-and tissue-specific endogenous tick promoters

> **NIH NIH R21** · UNIVERSITY OF NEVADA RENO · 2024 · $237,875

## Abstract

SUMMARY
The lack of a promoter-reporter system in ticks makes functional genomics studies challenging.
A few exogenous promoters that appear to work in tick cell lines are viral (i.e. CAAG/CMV
promoter) and are constitutively expressing. However, not all research questions can be
approached by constitutively expressing a gene. It is useful to gain temporal control over gene
expression. In eukaryotic cells, nuclear DNA and proteins combine to form chromatin, which
then undergoes complex and orderly folding to form chromosomes. For genes to be expressed,
chromatin must be in an open conformation. Open chromatin allows regulatory proteins to bind
to DNA and regulate DNA function. The assay for transposase-accessible chromatin with high-
throughput sequencing (ATAC-seq) enables high-throughput sequencing of open chromatin
regions with the help of transposases. ATAC-seq detects chromatin accessibility of related
genes and indicates their regulatory mechanisms. Thus, genes with chromatin accessibility in
promoters are more likely to be differentially expressed at the mRNA level. Therefore, by
combining the power of ATAC-seq to analyze chromatin accessibility in the promoter regions of
whole genes in ticks’ tissues and life stages and then screening differentially expressed genes
(DEGs) at the mRNA level by transcriptome sequencing technology (RNA-seq), we will obtain
temporally and spatially expressed genes and their promoters. Therefore, our hypothesis/
objective is that by combining gene expression (RNAseq) and open chromatin regions using
ATACseq (Aim 1), and promoter assays (Aim 2), we will identify constitutive and
stage/sex/tissue-specific promoters for gene expression in ticks. Our pioneering work in tick
genome sequencing and CRISPR-Cas9-based genome editing has now made tick gene-editing
possible and this proposal will further help us improve the gene-editing protocol by developing
the promoter-reporter systems that will allow the screening of mutants without the need to
sequence every individual.

## Key facts

- **NIH application ID:** 10896405
- **Project number:** 5R21AI176352-02
- **Recipient organization:** UNIVERSITY OF NEVADA RENO
- **Principal Investigator:** Monika Gulia-Nuss
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $237,875
- **Award type:** 5
- **Project period:** 2023-08-01 → 2026-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10896405

## Citation

> US National Institutes of Health, RePORTER application 10896405, Identification of stage-and tissue-specific endogenous tick promoters (5R21AI176352-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10896405. Licensed CC0.

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