Tissue-specific regulation of cyclin E transcription during Drosophila melanogaster embryogenesis.
Cyclin E is an essential regulator of S phase entry. We have previously shown that transcriptional regulation of the gene that encodes Drosophila cyclin E, DmcycE, plays an important role in the control of the G(1) to S phase transition during development. We report here the first comprehensive analysis of the transcriptional regulation of a G(1 )phase cell cycle regulatory gene during embryogenesis. Analysis of deficiencies, a genomic transformant and reporter gene constructs revealed that DmcycE transcription is controlled by a large and complex cis-regulatory region containing tissue- and stage-specific components. Separate regulatory elements for transcription in epidermal cells during cell cycles 14-16, central nervous system cells and peripheral nervous system cells were found. An additional cis-regulatory element drives transcription in thoracic epidermal cells that undergo a 17th cell cycle when other epidermal cells have arrested in G(1 )phase prior to terminal differentiation. The complexity of DmcycE transcriptional regulation argues against a model in which DmcycE transcription is regulated simply and solely by G(1) to S phase transcription regulators such as RB, E2F and DP. Rather, our study demonstrates that tissue-specific transcriptional regulatory mechanisms are important components of the control of cyclin E transcription and thus of cell proliferation in metazoans.
Jones
L
L
Centre for the Molecular Genetics of Development and Department of Molecular Biosciences, University of Adelaide, South Australia, Australia.
Richardson
H
H
Saint
R
R
D000818:Animals; D030801:Animals, Genetically Modified; D002453:Cell Cycle / Q000502:physiology*; D019927:Cyclin E / Q000235:genetics*; D004251:DNA Transposable Elements; D004331:Drosophila melanogaster / Q000196:embryology* / Q000235:genetics; D004625:Embryo, Nonmammalian / Q000502:physiology; D000078404:Epidermal Cells; D004817:Epidermis / Q000196:embryology; D005260:Female; D016193:G1 Phase; D018507:Gene Expression Regulation, Developmental; D018392:Genomic Imprinting; D008297:Male; D009024:Morphogenesis; D009420:Nervous System / Q000166:cytology / Q000196:embryology; D009928:Organ Specificity; D012045:Regulatory Sequences, Nucleic Acid; D015183:Restriction Mapping; D016196:S Phase; D014158:Transcription, Genetic
D019927:Cyclin E; D004251:DNA Transposable Elements