TitleUnmasking activation of the zygotic genome using chromosomal deletions in the Drosophila embryo.
Publication TypeJournal Article
Year of Publication2007
AuthorsDe Renzis, S, Elemento, O, Tavazoie, S, Wieschaus, EF
JournalPLoS Biol
Date Published2007 May
KeywordsAnimals, Base Sequence, Chromosome Deletion, Down-Regulation, Drosophila melanogaster, Drosophila Proteins, Female, Gene Expression Profiling, Gene Expression Regulation, Developmental, RNA, Messenger, RNA-Binding Proteins, Transcriptional Activation, Zygote

During the maternal-to-zygotic transition, a developing embryo integrates post-transcriptional regulation of maternal mRNAs with transcriptional activation of its own genome. By combining chromosomal ablation in Drosophila with microarray analysis, we characterized the basis of this integration. We show that the expression profile for at least one third of zygotically active genes is coupled to the concomitant degradation of the corresponding maternal mRNAs. The embryo uses transcription and degradation to generate localized patterns of expression, and zygotic transcription to degrade distinct classes of maternal transcripts. Although degradation does not appear to involve a simple regulatory code, the activation of the zygotic genome starts from intronless genes sharing a common cis-element. This cis-element interacts with a single protein, the Bicoid stability factor, and acts as a potent enhancer capable of timing the activity of an exogenous transactivator. We propose that this regulatory mode links morphogen gradients with temporal regulation during the maternal-to-zygotic transition.

Alternate JournalPLoS Biol.