BIO230H1 Lecture Notes - Lecture 5: Transmembrane Protein, Notch Signaling Pathway, Morphogen
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BIO230H1 Full Course Notes
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Mechanisms of changing gene expression: asymmetric division (intrinsic, symmetric division (extrinsic) Mechanism: partitioning cell fate determinants between different regions of the cell, which will be pulled apart to form 2 different daughter cells. 1 containing the cell fate determinants, one without. Requires: asymmetric determinants (positioned & partitioned correctly, all determinants are positioned onto one side, spindle alignment, ensures that the pulling apart of the cell splits the determinants. Inhibition: direct lateral inhibition, induction by diffusible signals, regulatory hierarchies. Process: all cells begin equal & are exerting inhibition upon one another. Notch & delta binding inhibits the notch cell. Stage 1 (mutual inhibition, no cell has differentiated) Each cell membrane has multiple notch & delta transmembrane proteins. When notch & delta bind- inhibits cell specialization (differentiation: adjacent cells mutually inhibit each other"s differentiation. The cell turns off its notch transmembrane protein: the other cell cannot inhibit it.
