Related Experiment Video

Updated: May 11, 2026

A Protocol for Genetic Induction and Visualization of Benign and Invasive Tumors in Cephalic Complexes of Drosophila melanogaster
07:23

A Protocol for Genetic Induction and Visualization of Benign and Invasive Tumors in Cephalic Complexes of Drosophila melanogaster

Published on: September 11, 2013

The Drosophila tuberous sclerosis complex gene homologs restrict cell growth and cell proliferation

N Tapon1, N Ito, B J Dickson

  • 1Massachusetts General Hospital Cancer Center, Charlestown, MA 02129, USA.

Cell
|May 12, 2001
PubMed

Insights

Tuberous sclerosis, a genetic disorder, arises from mutations in TSC1 or TSC2. Inactivating these genes in Drosophila causes identical phenotypes, including enhanced growth and cell size, offering insights into human disease mechanisms.

Area of Science:

  • Genetics
  • Developmental Biology
  • Cell Biology

Background:

  • Tuberous sclerosis is an inherited human disease characterized by hamartomatous tumors.
  • Mutations in the TSC1 or TSC2 genes are the known causes of tuberous sclerosis.
  • The TSC1 and TSC2 proteins form a complex that regulates cell growth and proliferation.

Purpose of the Study:

  • To characterize the function of Tsc1 and Tsc2/gigas genes in Drosophila.
  • To investigate the cellular mechanisms underlying tuberous sclerosis.
  • To explore the role of cell cycle regulators in TSC pathogenesis.

Main Methods:

  • Inactivating mutations were introduced into Drosophila Tsc1 and Tsc2/gigas genes.
  • Phenotypic analysis of mutant Drosophila was performed, focusing on growth and cell size.
  • Cell cycle progression and cyclin levels were analyzed in mutant cells.

Main Results:

  • Inactivating mutations in either Tsc1 or Tsc2/gigas resulted in an identical phenotype: enhanced growth and increased cell size without changes in ploidy.
  • Mutant cells exhibited reduced time spent in the G1 phase of the cell cycle.
  • Coexpression of Tsc1 and Tsc2 restricted tissue growth, reduced cell size, and decreased cell proliferation.
  • Elevated levels of Cyclin E and Cyclin A were observed in postmitotic mutant cells, suggesting inappropriate cell cycle re-entry.

Conclusions:

  • Drosophila Tsc1 and Tsc2/gigas genes play crucial roles in regulating cell growth, size, and proliferation.
  • Loss of Tsc1 or Tsc2 function leads to cell cycle dysregulation, mimicking aspects of human tuberous sclerosis.
  • Cyclin levels are critical in modulating the phenotype associated with Tsc1/Tsc2 mutations.

More Related Videos

The Drosophila Imaginal Disc Tumor Model: Visualization and Quantification of Gene Expression and Tumor Invasiveness Using Genetic Mosaics10:31

The Drosophila Imaginal Disc Tumor Model: Visualization and Quantification of Gene Expression and Tumor Invasiveness Using Genetic Mosaics

Published on: October 6, 2016

Induction and Diagnosis of Tumors in Drosophila Imaginal Disc Epithelia08:14

Induction and Diagnosis of Tumors in Drosophila Imaginal Disc Epithelia

Published on: July 25, 2017

Related Concept Videos

Negative Regulator Molecules01:23

Negative Regulator Molecules

Positive regulators allow a cell to advance through cell cycle checkpoints. Negative regulators have an equally important role as they terminate a cell’s progression through the cell cycle—or pause it—until the cell meets specific criteria.
Inhibition of Cdk Activity02:34

Inhibition of Cdk Activity

The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...
Replicative Cell Senescence02:15

Replicative Cell Senescence

Replicative cell senescence is a property of cells that allows them to divide a finite number of times throughout the organism's lifespan while preventing excessive proliferation. Replicative senescence is associated with the gradual loss of the telomere — short, repetitive DNA sequences found at the end of the chromosomes. Telomeres are bound by a group of proteins to form a protective cap on the ends of chromosomes. Embryonic stem cells express telomerase — an enzyme that adds the telomeric...
Abnormal Proliferation02:23

Abnormal Proliferation

Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
mTOR Signaling and Cancer Progression03:03

mTOR Signaling and Cancer Progression

The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
Cancer-Critical Genes II: Tumor Suppressor Genes01:05

Cancer-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...