Comp Exam (Midterm info) flashcards.txt

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  1. Autonomous specification vs conditional specification
    • Autonomous specification: pre-determined cells
    • Can be seen to have autonomous specification if cells are isolated and persist as the same cell type(ie: red cells) when transplanted into new cells
    • Conditional specification: ie red cells that are transplanted to new embryos turning a different color, due to PARACRINE SIGNALS of NEIGHBORING cells of the new embryo
  2. vg1 and role/contribution
    • MESODERM inducing signal
    • Located in the VEGETAL cytoplasm of embryo, where MESODERM formation occurs
    • Present from: MATERNAL contribution
  3. B-catenin and role/contribution
    • DORSAL MESODERM-inducing signal
    • MATERNALLY Expressed: for axes formation
    • Acts after cortical rotation of Dishevelled to DORSAL side..Dsh inhibits GSK-3 so B-catenin is STABLE on DORSAL side!
    • Wnt pathway activates Frizzled, then Dishevelled, and Dsh BLOCKS GSK-3 from degrading (Phosphorylating) B-catinn
  4. What happens if you target MESODERM-inducing signals for DEGRADATION?
    • This loss of signal, such as Vg1, causes DELAYED GASTRULATION.
    • If you knock down a lot of it(via RNAi for example), can arrest development and stop MESODERM from forming
  5. Role of Organizer genes examples, where expressed and role
    • Chordin and cerebus: Expressed in the organizer (near the dorsal-side of the mesoderm)
    • Inhibits Nodal, BMP and Wnt signaling: thereby allowing for ECTOPIC HEAD formation
  6. Characteristics of EMT
    • Cell contacts are lost as PRIMITIVE streak is formed during gastrulation..trans. to mesenchym cells
    • TGF-b (leading to Phos. of SMAD2/3) and Ras signaling required
    • SNAIL (TF) also aids in EMT by repressing E-cad, Claud, Occludin
  7. Snail-SMAD3/4 complex role
    • Aids in Endothelial to mesenchymal transition (EMT): by REPRESSING E-cadherin, Claudin, CAR and Occludin (Cell JUNCTION components)
    • Neg. regulated by GSK-3
    • SNAIL: Acts as a substrate for GSK-3, so when GSK-3 is inhibited, SNAIL expression should decrease, thereby decreasing repression of CAR and cad.
  8. Snail activation role in CANCER
    • It allows for the EMT transition, repressing EPITHELIAL markers CLAUDIN, occludin (cell jxn components) and enhancing mesenchymal markers (ie Vimentin)
    • This EMT allows for:
    • 1. LOSS of cell polarity
    • 2. ability for cell migration
    • 3. DeLAMINATION from neighboring cells
  9. Snail involvement with Wnt signaling
    • Snail interacts with b-catenin to PROMOTE Wnt dependent target gene expression
    • Snail acts to Decrease E-cadherin and Occludin and claudin, but is not needed to Increase Wnt activity by binding to B-catenin
    • End result of Wnt activation is to increase tumor growth
  10. Hox genes
    • Hox genes: such as Abd, can act to target TFs and molecules (ie ems, sal) result in the expression of REALIZATOR genes (cads) involved with:
    • 1. cell adhesion
    • 2. cell polarity
    • 3. cytoskeleton regulation
  11. Bicoid and caudal mechanism (with d4EHP)
    • Bicoid: expressed at the anterior region
    • Bicoid mRNA makes bicoid protein (translation triggered by fertilization), which binds to caudal UTR region: inhibiting translation of caudal
    • d4EHP: drosophila homolog that binds to bicoid to act to repress caudal mRNA
    • Caudal: expressed at the posterior
    • end result of bicoid mRNA: no caudal at anterior
  12. ERK signaling
    Involved in signaling in Anteriorization: NEGATIVELY regulated by B-catenin
  13. Epistatic
    Priot to (when looking at a pathway)
  14. Primitive streak / Hensen's node formation in chick embryo
    • Lays down the A/P axis.
    • Begins on marginal zone, mesoderm and endoderm internalize here
    • Once it gets long enough, anterior REGRESSES back to the posterior end, making HENSEN's Node
    • As cells enter primitive streak: become MESENCHYMAL cells
  15. Co-IP assay
    • Co-immunoprecipitation: Allows for the formation of two interacting proteins to appear on a blot, showing the two proteins together, with the single proteins and corresponding sizes used as a control
    • The molecular weight should be increased to show this interaction, thereby indicating the interaction has occurred
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Comp Exam (Midterm info) flashcards.txt
2014-11-13 01:56:42
Analysis Development Midterm review Comp

Analysis of Development Midterm review for Comp
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