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Updated: Mar 25, 2026
12:29
Upright Imaging of Drosophila Egg Chambers
Published on: March 13, 2015
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Bicoid gradient formation and function in the Drosophila pre-syncytial blastoderm
Zehra Ali-Murthy1, Thomas B Kornberg1
1Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States.
Elife
|February 18, 2016
Summary
New findings reveal Bicoid (Bcd) protein production begins earlier than previously thought, starting in stage 14 oocytes and forming gradients in early embryos. This challenges the established timeline for embryonic patterning in Drosophila.
Area of Science:
- Developmental Biology
- Genetics
- Molecular Biology
Background:
- The Bicoid (Bcd) protein gradient is crucial for establishing the anterior-posterior axis in Drosophila embryos.
- Previous understanding suggested Bcd protein synthesis initiates post-fertilization and functions post-nuclear division cycle 9-10.
Purpose of the Study:
- To investigate Bcd protein production and gradient formation in earlier developmental stages (stage 14 oocytes and pre-syncytial blastoderm embryos).
- To re-evaluate the timeline of Bcd gradient establishment and target gene regulation.
Main Methods:
- Development of novel, highly sensitive analytical methods for analyzing stage 14 oocytes and pre-syncytial blastoderm embryos.
- Quantitative analysis of Bcd RNA and protein distribution in early embryos.
Main Results:
- Bicoid (Bcd) protein is synthesized in stage 14 oocytes.
- Matching concentration gradients of bcd RNA and Bcd protein are observed in nuclear cycle 2-6 embryos.
- Bcd's regulation of target gene expression is detectable at nuclear cycle 7, earlier than previously established.
Conclusions:
- Bicoid protein production and gradient formation commence earlier in oogenesis and early embryogenesis than previously understood.
- These findings necessitate a revision of the established model for Drosophila anterior-posterior axis determination.
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