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Gene Trapping Using Gal4 in Zebrafish
Published on: September 29, 2013
Gene trapping identifies transiently induced survival genes during programmed cell death
1Laboratory for Molecular Hematology, University of Frankfurt Medical School, 60590 Frankfurt am Main, Germany.
Genome Biology
|August 23, 2001
Summary
Hematopoietic cells activate survival genes to impede apoptosis when growth factors are withdrawn, demonstrating that cell death is a conflict between survival and death signals, not a default process.
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- Cells possess a constitutive death machinery, often repressed by survival factors, leading to default cell death upon their absence.
- However, apoptosis induction by inhibitors suggests transcriptional activity can impede cell death in some cases.
- Investigating transcriptional interference with cell death and survival mechanisms is crucial.
Purpose of the Study:
- To identify transcriptional mechanisms that interfere with cell death and survival.
- To isolate genes involved in preventing apoptosis in hematopoietic cells.
Main Methods:
- Utilized gene trap mutagenesis combined with the Cre/loxP site-specific recombination system.
- Infected interleukin-3 (IL-3)-dependent hematopoietic cell line FLOXIL3 with U3Cre gene trap virus.
- Screened for clones exhibiting factor independence upon IL-3 withdrawal.
Main Results:
- Isolated 125 clones that became independent of IL-3 after its withdrawal from a library of ~2x10^6 proviral integrations.
- Analysis of integration sites revealed 17% mapped to known genes, 11% to ESTs/cDNAs of unknown function, and 72% had no database matches.
- A majority of identified known genes encoded proteins with known survival functions.
Conclusions:
- Hematopoietic cells activate survival genes that actively impede cell death following IL-3 withdrawal.
- This activation reduces apoptosis and enhances cell survival when exposed to transient apoptotic stimuli.
- Apoptosis in these cells results from a balance between competing death and survival signals, not simply passive default death.
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