Related Experiment Video

Updated: May 19, 2026

Sealable Femtoliter Chamber Arrays for Cell-free Biology
13:44

Sealable Femtoliter Chamber Arrays for Cell-free Biology

Published on: March 11, 2015

Dynamics of protein noise can distinguish between alternate sources of gene-expression variability

Abhyudai Singh1, Brandon S Razooky, Roy D Dar

  • 1Department of Chemistry and Biochemistry, University of California, San Diego, CA, USA.

Molecular Systems Biology
|August 30, 2012
PubMed

Insights

This study introduces a new method to distinguish gene expression noise sources. The findings suggest promoter fluctuations are the main driver of noise in HIV-1 expression.

Area of Science:

  • Molecular Biology
  • Systems Biology
  • Genetics

Background:

  • Gene expression noise arises from mRNA and promoter fluctuations.
  • Distinguishing these sources is difficult with standard methods, especially at high cellular mRNA concentrations.
  • Existing techniques like mRNA single-molecule fluorescence in situ hybridization (smFISH) have limitations.

Purpose of the Study:

  • To develop and validate a novel perturbation method to differentiate between mRNA birth/death and promoter fluctuations.
  • To apply this method to the HIV-1 gene expression system.
  • To provide a complementary approach to smFISH for noise source identification.

Main Methods:

  • A perturbation approach measuring transient changes in protein variance.
  • Utilizing transcriptional blockage to observe differential noise increases.
  • Experimental validation in the HIV-1 model system.
  • Operating effectively in conditions of high molecular numbers.

Main Results:

  • The perturbation method successfully discriminates between mRNA and promoter noise sources.
  • The study found that promoter fluctuations are the predominant source of noise in HIV-1 expression.
  • The method proved effective even at high cellular mRNA concentrations.

Conclusions:

  • Promoter fluctuations are identified as the primary source of noise in HIV-1 gene expression.
  • The developed perturbation method is a valuable tool complementing smFISH.
  • This approach can be integrated with existing GFP-tagged libraries for broader noise analysis.

More Related Videos

Processing of Primary Brain Tumor Tissue for Stem Cell Assays and Flow Sorting08:14

Processing of Primary Brain Tumor Tissue for Stem Cell Assays and Flow Sorting

Published on: September 25, 2012

Determining Genome-wide Transcript Decay Rates in Proliferating and Quiescent Human Fibroblasts07:03

Determining Genome-wide Transcript Decay Rates in Proliferating and Quiescent Human Fibroblasts

Published on: January 2, 2018

Related Concept Videos

mRNA Stability and Gene Expression02:51

mRNA Stability and Gene Expression

The structure and stability of mRNA molecules regulates gene expression, as mRNAs are a key step in the pathway from gene to protein. In eukaryotes, the half-life of mRNA varies from a few minutes up to several days. mRNA stability is essential in growth and development. The absence of the proteins regulating its stability, such as tristetraprolin in mice, can cause systemic issues, including bone marrow overgrowth, inflammation, and autoimmunity.
Cis-acting Elements involved in mRNA stability
mRNA Stability and Gene Expression02:51

mRNA Stability and Gene Expression

The structure and stability of mRNA molecules regulates gene expression, as mRNAs are a key step in the pathway from gene to protein. In eukaryotes, the half-life of mRNA varies from a few minutes up to several days. mRNA stability is essential in growth and development. The absence of the proteins regulating its stability, such as tristetraprolin in mice, can cause systemic issues, including bone marrow overgrowth, inflammation, and autoimmunity.
Cis-acting Elements involved in mRNA stability
Structure of a Gene01:30

Structure of a Gene

A gene is the fundamental unit of heredity. Every individual has two copies of each gene, one inherited from each parent. Although most people contain the same genes, there is a small fraction that is slightly different amongst people. A gene with a small difference in its sequence of DNA bases forms different alleles, contributing to different phenotypes.
However, only 1% of the DNA is composed of genes that encode proteins; the rest, 99% is non-coding DNA. This non-coding DNA performs...
What is Gene Expression?01:36

What is Gene Expression?

A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is comprised  of nucleotides and proteins are comprised of amino acids, a mediator is required to convert the information encoded in DNA into proteins. This mediator is the messenger RNA (mRNA). mRNA copies the blueprint from DNA by a process called transcription. In eukaryotes, transcription occurs in the nucleus by complementary base-pairing with the DNA template. The mRNA is then processed and...
What is Gene Expression?01:42

What is Gene Expression?

Overview
Gene expression is the process in which DNA directs the synthesis of functional products, that is, proteins. Cells can regulate gene expression at various stages. It allows organisms to generate different cell types and enables cells to adapt to internal and external factors.
Genetic Information Flows from DNA to RNA to Protein
A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is made up of nucleotides and proteins consist of amino...
What is Gene Expression?01:42

What is Gene Expression?

Overview
Gene expression is the process in which DNA directs the synthesis of functional products, that is, proteins. Cells can regulate gene expression at various stages. It allows organisms to generate different cell types and enables cells to adapt to internal and external factors.
Genetic Information Flows from DNA to RNA to Protein
A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is made up of nucleotides and proteins consist of amino...