BIOC19H3 Lecture Notes - Lecture 6: Rna, Epiphyseal Plate, Sertoli Cell
Document Summary
Signal transduction pathways in development: rtk. Morphogen gradient: morphogen concentration can determine which genes are being expressed at a given time, experiment: place beads containing a morphogen (e. g. activin) on unspecified cells (e. g. early xenopus embryo) High [activin] expression of goosecoid gene; is a t. f. for dorsal structures in frog. Low [activin] expression of xbra gene (t. f. Below threshold no activation of xbra or goosecoid (cid:494)default(cid:495) gene expression leading to formation of heart and blood vessels. Signals transduction in development: ligand receptor cellular response, some developmentally important signalling pathways are: Receptor tyrosine kinase pathway: hspg: heparin sulfate proteoglycans, fgf: fibroblast growth factor (ligand, gef: gtp exchange factor (aka guanine nucleotide releasing factor , gap: gtpase-activating protein. Gnrp: raf: protein kinase that phosphorylates at amino acids s and t, mek: mitogen-activated protein kinase kinase (mapkk, erk: extracellular signal regulated kinase (mapk, after fgf binding, it causes phospryl. of receptor. Gap or gef can now bind to tail.
