Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Getting the terminology down: C. elegans VulvaSlide 13Inductive and lateral signals induce the vulvaA signal from P6.p actives notch (lin-12) in P5.p and P7.pSlide 16Generation of Different Cell Types From Equivalent Cells in C. elegans: Initial specification of the Anchor Cell also requires NotchSlide 18Slide 19Slide 20Final noon Thursday May 5I will post answers for any remaining questions emailed to me by noon on Tuesday May 3Imprinting results from pre-programmeddifferences in DNA methylation of selected genes in the sperm and eggImprinted genes affect fetal growthInsulin growth factor 2 Insulin growth factor 2 (Igf2) receptor (Igf2r)growth growthWhat happens if dad’s copy of Igf2 is deleted?Insulin growth factor 2 Insulin growth factor 2 (Igf2) receptor (Igf2r)growth growthWhat happens if mom’s copy of Igf2 isn’t imprinted?Insulin growth factor 2 Insulin growth factor 2 (Igf2) receptor (Igf2r)overgrowth growthBeckwith-Weidemann syndromeWhat if mom’s copy of Igf2r is deleted?Insulin growth factor 2 Insulin growth factor 2 (Igf2) receptor (Igf2r)overgrowth growthT F A mouse that inherits a mutant maternal copy of Igf2 exhibits fetal undergrowth.T F A mouse that inherits a mutant Igf2r gene from its mother is born 40% smaller than normal.T F Maternal imprinting of the human Igf2r gene prevents fetal overgrowth.T F Maternal imprinting of the human Igf2 gene prevents fetal overgrowth.T F Mutations in the paternal copy of the mouse Igf2 gene cause mice to be born 40% smaller than normal.Chromatin transferred from myoblasts can transform untreated fat cells. Experiment #2Transformation frequency suggests only one or few of the genes have this abilityC3H/10T cells = fibroblast cells (make connective tissue, synthesize the extracellular matrix and collagen)If treated with azacytadine, C3H/10T cells can be induced to form muscle, fat and cartilage cells.Ultimately a single gene was identified-myoD-whose expression could convertany other cell type into muscle cellsGetting the terminology down: C. elegans VulvaFigure 6.27Anchor cell (AC)GonadVPCsEarly larval stageP3.p-P8.p are the Vulva Precursor Cells (VPCs)ACBasement membraneGonadLater larval stageP5.p,P6.p and P7.p lineages make the vulvaP3.p,P4.p and P8.p lineages non-vulval1°2°2° 3°3°P6.p P7.pP5.pP3.p P4.p P8.p3°The Ras pathway is abnormally activated in many human tumorseg: pancreatic cancer, colorectal cancer, lung adenocarcinoma, gall bladder cancer, bile duct cancer and thyroid cancersignal(VPC cells)LIN-3Another representation of the RAS pathwayInductive and lateral signals induce the vulvagonadAnchor cellVPCsP3P4P5P6P7P8VPCs after induction1°3°3°3°2°2°The primary and secondary cells form the vulvaA signal from P6.p actives notch (lin-12) in P5.p and P7.pFigure 6.27Both membrane and receptor are membrane bound!The transmembrane receptor is the Lin-12 protein, a receptor protein related to Notch “ Primary cell”“ Secondary cells”Generation of Different Cell Types From Equivalent Cells in C. elegans: Initial specification of the Anchor Cell also requires NotchFigure 6.28The signal:lag-2 (delta)The receptor: lin-12 (notch)gonadanchorcell3° cell3° cell 3° cellIf anchor cell signaling is disrupted, all VPCs cells adopt a non-vulva fate3° cell3° cell3° cellno
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