Patterning Development in the Early Embryo Eric Wieschaus, February 5, 2009 HHMI & Molecular Biology Department, Princeton University

Lecture Overview Following fertilization, the single celled embryo undergoes a number of mitotic divisions to produce a ball of cells called a blastula or blastoderm. Although these cells are all genetically identical, they gradually begin to express different gene products that reflect the regions of the adult body they will form. In my first lecture I discuss how these initial patterns of gene expression arise. In Drosophila, a maternally supplied transcription factor called Bicoid plays a particularly important role. Bcd RNA is anchored at the anterior end of the egg but is only translated after fertilization. From that anterior source, Bcd protein is thought to diffuse through the egg, establishing a concentration gradient that activates different genes at different thresholds.

Part 1: Where does pattern come from? Click image above to start seminar in 320x240 format Click here to view in larger 640x480 format*   QuickTime 7 Required    * System Requirements (there may be a few seconds delay before seminars start) Downloads in alternative formats: (To Save, Right Click a link below and select "Save Target/Link As") QuickTime     MP4     iPod/iPhone Video PowerPoint Slides Format Descriptions Download Accelerator/Resume Broken Downloads Software

Part 2: Stability of Morphogen Gradients & Movement of Molecules   Part 3: Evolution of Bicoid-based Patterning in the Diptera Speaker Bio    Related Articles