Related Experiment Video
Updated: May 21, 2026
10:13
Immunofluorescent Staining for Visualization of Heterochromatin Associated Proteins in Drosophila Salivary Glands
Published on: August 21, 2021
[Drosophila Fab-7 insulator effectively blocks polycomb-mediated repression in transgenic lines]
Genetika
|June 12, 2012
Summary
The bithorax complex (BX-C) utilizes insulators like Fab-7 to separate active and repressed gene domains. Fab-7, with GAF-binding sites, protects transcription from Polycomb-mediated silencing.
Area of Science:
- Developmental Biology
- Genetics
- Epigenetics
Background:
- The bithorax complex (BX-C) regulates Drosophila development with nine parasegment-specific enhancers.
- Polycomb (Pc)-mediated repression creates active and repressed gene domains, separated by insulators.
Purpose of the Study:
- To investigate the function of insulators in separating active and repressed gene domains within the BX-C.
- To determine if the Fab-7 insulator can block Polycomb-dependent silencing.
Main Methods:
- Utilized transgenic model systems to identify and test insulator function.
- Assessed the ability of the Fab-7 insulator to protect the yellow gene from a potent silencer in the Ultra-bithorax (Ubx) regulatory domain.
Main Results:
- Identified three insulators in the BX-C capable of blocking enhancers in transgenic systems.
- Demonstrated that the Fab-7 insulator protects yellow gene transcription from a powerful Polycomb-dependent silencer.
- Confirmed that GAF-binding sites are essential for Fab-7's barrier activity.
Conclusions:
- Fab-7 functions as a barrier element, preventing the spread of Polycomb-mediated repression.
- Insulators play a crucial role in maintaining distinct epigenetic domains within the BX-C.
Related Concept Videos
01:52Eukaryotic Transcription Inhibitors
Certain biochemical processes, such as embryonic development and cell growth regulation, depend on the repression of specific genes. DNA binding proteins known as eukaryotic transcription inhibitors regulate the repression of gene expression in eukaryotes. The presence of these inhibitors at the required location and time in the cell is triggered by the presence of hormones and additional signals from other cells.
Eukaryotic transcription inhibitors usually contain two distinct domains, a DNA...
Eukaryotic transcription inhibitors usually contain two distinct domains, a DNA...
02:32Position-effect Variegation
In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.