文档介绍：Chapter 18 Gene Regulation during Development
Outline
Topic 1 Three Strategies by which Cells Are Instructed to Express Specific Sets of Genes during Development
Topic 2 Examples of the Three Strategies for Establishing Differential Gene Expression
Topic 3 The Molecular Biology of Drosophila Embryogenesis
Topic 1: Three Strategies by which Cells Are Instructed to Express Specific Sets of Genes during Development
Three Strategies:
mRNA localization
Cell-to-cell contact
Signaling through the diffusion of secreted signaling molecules
Some mRNAs e Localized within Eggs and Embryos due to an Intrinsic Polarity in the Cytoskeleton
The asymmetrically distributed mRNA is transported along element of the cytoskeleton from – to the growing + end.
Adaptor protein binds to 3’untranslated trailer (3’UTR) region of the mRNA, has two domains: one recognizes the 3’ UTR,the other associates with myosin.
Cell-to-Cell Contact and Secreted Cell Signaling Molecules both Elicit changes in Gene Expression in Neighboring Cells
Cell-to-Cell Contact: signaling molecules remain on the surface control gene expression only in cells which are directly, physically contact with the signaling cell.
A given signal is recognized by a specific receptor on the surface of recipient cells, triggers changes in gene expression in them.
Then signal transduction pathways is involved in munication from the cell surface receptor to the nucleus.
Signal Transduction Pathways
Ligand-receptor interaction induces kinase cascade that modifies regulatory proteins present in nucleus.
Activated receptor cause the release of DNA-binding protein so it can enter the nucleus, regulate gene transcription.
The intracytoplasmic domain of the activated receptor is cleaved to enter the nucleus and interact with DNA-binding protein.
Gradient of Secreted Signaling Molecules
Two concepts:
Positional information:
a cell’s development is influenced by its location within the developing embryo.
Morphogens:
signal