9
Developmental Biology (Subject) / Lecture 2 (Lesson)
- Spearman Organiser acts non-autonomously signals travel through the embryo a hierarchical chain of inductions
- Hippo Pathway Serine/threonine Kinase cascade Hpo phosphorylates the protein kinase Warts (Wts) Hpo is a family of Ste-20 family protein kinases Salvador (Sav) regulates Hpo Mob (Mats) regulates Wts Yorkie (Yki) is a transcriptional coactivator
- Speman organizer secretes Chordin and noggin prevents BMP-4 signaling --> cells become nerve cells
- Morphogens deffinition longe range signaling molecules response is determined by concentration thresholds in conc. describe position
- Morphogens spread amount that is produced diffusion rate clearance (turnover rate)
- Morphogens: High threshold genes and low threshold genes High: expression only takes place if conc. of morphogen is high Low: expression takes place even if conc. of morphogen is low (but also at high conc.)
- Canonical Wnt-signaling pathway Wnt binds to Frizzled releases β-catenin from destruction box β-catenin can enter nucleus and bind to TCF --> gene expression of Myc/cyclin-D1
- Cell polarity can be controlled at 3 levels Single cell: intracellular signal Small group of cells: short range signals from stem cell niche Tissue level: like Wnt or Hedgehog signaling
- How to choose a model organism genetic or transplantation studies Size generation time brood size maintanance
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