Related Experiment Video
Updated: May 9, 2026
10:10
Dissection and Immunostaining of Imaginal Discs from Drosophila melanogaster
Published on: September 20, 2014
Contribution of distinct homeodomain DNA binding specificities to Drosophila embryonic mesodermal cell-specific gene
Brian W Busser1, Stephen S Gisselbrecht, Leila Shokri
1Laboratory of Developmental Systems Biology, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States of America.
Plos One
|August 8, 2013
Summary
Homeodomain (HD) transcription factors (TFs) control development, but their similar DNA binding poses challenges. This study modified enhancers to clarify specific HD subclass roles in Drosophila mesoderm development, revealing distinct inputs and regulatory network targeting.
Area of Science:
- Developmental Biology
- Genetics
- Molecular Biology
Background:
- Homeodomain (HD) proteins are crucial transcription factors (TFs) for development.
- Many HD TFs recognize similar DNA sequences, complicating the study of individual roles.
- Drosophila embryonic mesoderm development relies on various HD TFs, including Hox, NK-2, and Six families.
Purpose of the Study:
- To investigate the specific roles of different HD TF subclasses in Drosophila embryonic mesoderm development.
- To determine how HD TF binding site modifications affect enhancer function.
- To elucidate the contribution of individual HD subclasses to gene regulatory networks.
Main Methods:
- Utilized protein binding microarrays (PBMs) to determine DNA binding specificities of diverse HDs.
- Modified nucleotide sequences of mesodermal enhancers to be recognized by specific HD subclasses.
- Assayed enhancer function in transgenic reporter assays in Drosophila embryos.
Main Results:
- Individual mesodermal enhancers receive distinct transcriptional input from Identity HDs (I-HDs) and Hox subclasses.
- Enhancers regulating upstream components of the mesodermal regulatory network are targeted by Six class HDs.
- NK-2 HD binding sequences are essential for activating gene expression in multiple mesodermal tissues, suggesting a pioneer role for Tinman (Tin).
Conclusions:
- HD TFs from multiple subclasses play critical roles in specifying mesodermal cell identity and coordinating gene regulatory networks.
- Understanding specific HD-DNA interactions is key to deciphering complex developmental processes.
- This research provides insights into the functional diversification of HD TFs in orchestrating mesoderm development.
Related Concept Videos
02:23Master Transcription Regulators
Master transcription regulators are regulatory proteins that are predominantly responsible for regulating the expression of multiple genes. Often these genes work in concert to drive a complex process. Activation of a master transcription regulator can lead to a cascade of transcriptional activation necessary for that outcome. These regulators can directly bind to the regulatory sequences of the various genes involved, or they can indirectly regulate transcription by binding to regulatory...
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.
01:30General Transcription Factors
Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of...
02:45The Ratio of X Chromosome to Autosomes
In most organisms, sex is determined by the ratio of X and Y chromosomes. However, in some organisms, such as Drosophila and C.elegans, sex is determined by the ratio of the number of X chromosomes to the number of sets of autosomes. The Y chromosome in Drosophila is active but does not determine sex. It contains genes responsible for the production of sperms in adult flies.
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
02:33Combinatorial Gene Control
Combinatorial gene control is the synergistic action of several transcriptional factors to regulate the expression of a single gene. The absence of one or more of these factors may lead to a significant difference in the level of gene expression or repression.
The expression of more than 30,000 genes is controlled by approximately 2000-3000 transcription factors. This is possible because a single transcription factor can recognize more than one regulatory sequence. The specificity in gene...
The expression of more than 30,000 genes is controlled by approximately 2000-3000 transcription factors. This is possible because a single transcription factor can recognize more than one regulatory sequence. The specificity in gene...
00:57Cellular Differentiation
How does a complex organism such as a human develop from a single cell? It all starts from a single fertilized egg which gives rise to a vast array of cell types, such as nerve cells, muscle cells, and epithelial cells that characterize the adult? Throughout development and adulthood, cellular differentiation leads cells to assume their final morphology and physiology. Differentiation is the process by which unspecialized cells become specialized to carry out distinct functions.
A zygote is a...
A zygote is a...