A sequence-specific DNA-binding protein that activates fushi tarazu segmentation gene expression

Area of Science:

• Developmental Biology
• Genetics
• Molecular Biology

Background:

• The Drosophila segmentation gene fushi tarazu (ftz) exhibits dynamic striped expression during the cellular blastoderm stage.
• A specific DNA sequence, the zebra element, upstream of the ftz gene, directs this striped expression pattern.

Purpose of the Study:

• To identify and characterize DNA-binding factors regulating the expression of the fushi tarazu (ftz) gene.
• To investigate the role of identified factors in the striped expression pattern of ftz during Drosophila embryogenesis.

Main Methods:

• Purification of a sequence-specific DNA-binding factor, FTZ-F1, from Drosophila embryo extracts.
• In vitro DNA-binding assays to determine FTZ-F1 binding sites within the ftz gene regulatory regions (zebra element and protein-coding sequence).
• Analysis of lacZ reporter gene expression in transgenic Drosophila embryos with mutated FTZ-F1 binding sites.

Main Results:

• FTZ-F1 was purified and found to bind to specific sites within the ftz zebra element and coding sequence.
• FTZ-F1 DNA-binding activity correlates temporally with ftz stripe expression in early embryos.
• Mutations in FTZ-F1 binding sites within the zebra element significantly reduce lacZ expression intensity in specific stripes.

Conclusions:

• FTZ-F1 is a sequence-specific DNA-binding protein that plays a critical role in regulating fushi tarazu (ftz) gene expression.
• FTZ-F1 acts as a transcriptional activator, essential for establishing the precise striped expression pattern of ftz during Drosophila segmentation.