Parameters controlling transcriptional activation during early Drosophila development
Cell
|March 28, 1986
Summary
During Drosophila development, gene transcription begins around mitotic cycle 11 or 12. All genes become ready for activation by cycle 10, but nuclear division functions suppress their expression.
Area of Science:
- Developmental Biology
- Molecular Biology
- Genetics
Background:
- Early Drosophila development involves rapid mitotic cycles.
- Understanding gene transcription regulation is crucial for developmental processes.
Purpose of the Study:
- To investigate the timing of gene transcription during early Drosophila development.
- To identify when different gene classes become transcriptionally active.
- To determine factors influencing the onset of high transcriptional activity.
Main Methods:
- In vivo RNA pulse-labeling in Drosophila embryos.
- Gel electrophoresis to analyze synthesized RNA.
- Manipulation of cell cycle duration using cycloheximide.
Main Results:
- Synthesis of rRNA, tRNAs, 5S RNAs, snRNAs, poly(A)+ RNAs, and histone mRNAs begins in cycle 11 or 12.
- Histone genes activate during S phase, peaking in cycle 12.
- Nonhistone genes activate during G2, peaking in cycle 14.
- High transcriptional activity of cycle 14 can be induced earlier with cycloheximide, but not before cycle 10.
Conclusions:
- All gene classes acquire competence for activation by cycle 10.
- Nuclear division functions differentially suppress gene activation.
- Differential gene expression timing is critical for Drosophila development.
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