Related Experiment Video
Updated: Jul 11, 2026
10:31
The Drosophila Imaginal Disc Tumor Model: Visualization and Quantification of Gene Expression and Tumor Invasiveness Using Genetic Mosaics
Published on: October 6, 2016
Cosuppression, flower color patterns, and metastable gene expression States
Science (New York, N.Y.)
|May 5, 1995
Summary
Plant transgenes trigger cosuppression, a nonlinear gene silencing mechanism. This phenomenon, influenced by flower structure, leads to stable, heritable changes in gene expression and plant traits.
Area of Science:
- Plant molecular biology
- Gene regulation
- Developmental biology
Background:
- Transgenes in plants can induce cosuppression, a phenomenon where homologous endogenous genes are silenced.
- Cosuppression is a nonlinear response to increased gene expression or dosage, leading to significant phenotypic changes.
- This gene silencing is organized by plant morphology and is sensitive to developmental and physiological factors.
Purpose of the Study:
- To investigate the organization and regulation of cosuppression patterns in plants.
- To understand the role of transgene transcription states in mediating cosuppression.
- To explore how morphological features influence gene silencing patterns and their stability.
Main Methods:
- Utilizing pigment transgenes to visualize and analyze cosuppression patterns.
- Observing the organization of cosuppression by flower morphology.
- Investigating the metastable nature and regulatory states of cosuppression.
- Examining the transmission of regulatory states through plant development.
Main Results:
- Pigment transgenes induce metastable cosuppression patterns that are organized by flower morphology.
- Pattern organization and metastability are linked to regulatory states, likely transgene transcription states.
- These regulatory states respond to morphological cues and are influenced by plant physiology and development.
- Shifts between regulatory states can be highly ordered and stably maintained throughout plant growth.
Conclusions:
- Cosuppression in plants is a complex regulatory process influenced by transgene dosage, morphology, and developmental state.
- Metastable patterns of gene silencing can be stably inherited, impacting plant phenotypes.
- Understanding cosuppression provides insights into gene regulation and transgene behavior in plants.
Related Concept Videos
01:43Incomplete Dominance
Gregor Mendel's work (1822 - 1884) was primarily focused on pea plants. Through his initial experiments, he determined that every gene in a diploid cell has two variants called alleles inherited from each parent. He suggested that amongst these two alleles, one allele is dominant in character and the other recessive. The combination of alleles determines the phenotype of a gene in an organism.
01:05Cancer-Critical Genes II: Tumor Suppressor Genes
Genes usually encode proteins necessary for the proper functioning of a healthy cell. Mutations can often cause changes to the gene expression pattern, thereby altering the phenotype.
When the function of certain critical genes, especially those involved in cell cycle regulation and cell growth signaling cascades, gets disrupted, it upsets the cell cycle progression. Such cells with unchecked cell cycles start proliferating uncontrollably and eventually develop into tumors.
Such genes that act...
When the function of certain critical genes, especially those involved in cell cycle regulation and cell growth signaling cascades, gets disrupted, it upsets the cell cycle progression. Such cells with unchecked cell cycles start proliferating uncontrollably and eventually develop into tumors.
Such genes that act...
01:12Loss of Tumor Suppressor Gene Functions
Tumor suppressor genes are normal genes that can slow down cell division, repair DNA mistakes, or program the cells for apoptosis in case of irreparable damage. Hence, they play an essential role in preventing the proliferation of damaged cells.
When the tumor suppressor genes develop mutations or are lost, cells start growing out of control, leading to cancer. However, a single functional copy of the tumor suppressor gene is enough for the cells to maintain their normal functions and cell...
When the tumor suppressor genes develop mutations or are lost, cells start growing out of control, leading to cancer. However, a single functional copy of the tumor suppressor gene is enough for the cells to maintain their normal functions and cell...
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.
01:22MicroRNAs
MicroRNA (miRNA) are short, regulatory RNA transcribed from introns (non-coding regions of a gene) or intergenic regions (stretches of DNA present between genes). Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself, forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA...
01:22MicroRNAs
MicroRNA (miRNA) are short, regulatory RNA transcribed from introns—non-coding regions of a gene—or intergenic regions—stretches of DNA present between genes. Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA ends...