MCD BIO 138 Lecture Notes - Lecture 16: Catenin, Ephrin, Ephrin Receptor
15 Dec 2016
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Cilia in node generate directional flow of ec fluid (same polarity) Directional flow leads to asymmetric gene expression in meso on other sides of embryo. Mutations in dynein disrupt ciliary function -> random organ location. Loss of cdx2 -> intestinal cells gain stomach cell characteristics b/c it is the more anterior cell type. Overexpression of cdx2 -> stomach cells transformed into intestinal cells. Regional specificity of induction depends on lateral plate mesoderm. Hox gene boundaries correlate w/ morphological boundaries in gut tube. Specific hox gene mutations -> specific gut tube structures affected. Apical constriction, change cadherin expression -> pinch cells apart. Localize proliferation, migration of cells in epithelial sheet, ecm breakdown and resynthesis to allow movement. Mesenchyme affects stem cells b/c of its secreted signals. Off in villus - no proliferation, has differentiated cells. Bmp that inhibit stem cell renewal + promote differentiation. Wnt + wnt receptor -> b catenin free to enter nucleus -> form complex w/ tcf (tf)
