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28 Cards in this Set
- Front
- Back
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hemangioblasts
enriched in___during embryogenesis 3 markers commitments of it initiated in___of mouse mebryo |
-bipotential precursors of hemopoietic stem cells and angioblasts
-primitive streak -Flk-1 (VEGFR2), brachyury (T gene),and Eng -primitve streak |
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brachyury___marker
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mesodermal
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how do we find out the 2 markers of hemangioblasts
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-blast colony assay
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-blast colony assay
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take cells from primitive streak
-add GFP to brachury locus -shows co expression of brachury and Flk-1 |
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co expression of brachury and Flk-1 distributes into (2)
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extra-embryonic mesoderm
intra‐embryonic mesoderm. |
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2 important consideration
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-critical functional need for specific hemopoeitic cells
-maturation and expansion if HSCs for postnatal renewing hemopoesis |
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-____is frist hemopoeitic tissue with temporary hemopoeissis (little dHSC production)
-______invlved in expansion,maturation of definitive HSC for postnatal hemopoesis |
yolk sac
embryonic sites (aorta-gonad-mesenopheric region, liver, bone marrow) |
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hemangioblasts distirbuted to extra embryonic also identified by sites of (2)
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blood islet formation
vessel formation |
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_____another possible early marker within hemangioblast
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endoglin
*required for proper hemopoeitic development |
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Eng (endoglin) identifies first hemopoeitic progenitors durin development, recepto needed for interpetation of____signals
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TGF/BMP signals
ie Eng regulator of TGF/BMP signalling at hematopoeisis origin |
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hemangioblast express brachury,Flk 1, Eng (markers for extra embryonic hemopoesis) then migratory cells mature/distribute as
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Flk-1+ and Eng+ cells in yolk sac chorioallantoic regions (early placental regions)
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Utero-placental circulaton inefficient for further
growth and is replaced by a closed Primitive Circulatory system with active primitive heart. Angioblasts (2) |
form vessels in the extra-‐embryonic
mesenchyme and join those forming in the embryo |
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primitve closed circulatory need differentiation of___tubes connected to heart tube
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endothelial
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heart tube functional as early as
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21-22 day
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mechanical force of moving blood, plays role in_____
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intravacular (hemogenic endothelial) formation of blood
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primitive closed circ system:
1) 2) 3) |
- hemangioblast distribution, yolk sac has hemopoeisis in islets on surface, other sites many vessles
-heart beats (day 21-22) propel blood, have circulating dorsal aortic blood via placenta before returning to heart -caudal end of heart tube get blood from: embryo body, yolk sace (vitelline veins), placents (umbilical veins) pump blood through paired dorsal aorte through umbilical arteries to placenta for gas exchange |
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underlying yolk sac endoderm gives essential factors (1) for formation of (2)
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indian hedgehog (IHH)
blood islets/vessels |
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first wave of primitive hemopoeisis makes (4)
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primitive erythrocytes,
HSCs megakaryocytes monocytes, |
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fluid and___(from endoderm) added to primitive blood
nucleated erythroblasts large and faciliaate |
alpha fetoprotein
opening of forming compact vessel |
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angiogenesis of Flk-1+ forms
which will then which will then |
-vessel networks on yolk sac surface
-join vessel in other extra embryonic sites, connecting stalk(future umbilical vessels) , chorion -join intra embryonic vessls to form intra mebryonic hemangiblasts |
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yolk sac _____produce all the same hemopoeitic cell types *listen
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DOES NOT
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1) hemangioblast-->angioblast (unipotent)-->flk 1--> _____ -->______-->recruits ______(2)--> lry capillary plexus
or hemngioblast --> angioblast-->-__ |
endothelia
mitosis sprouting smooth muscle/pericytes HSC |
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2) hemangioblast-->pluripotent stem cell --> (5)
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erythrocytes
megakaryocytes granulocytes macrophages lymphocytes (B and T) |
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primitve streak_has (2) sites __and___mesenchymal
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extra
intra |
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Vasculogenesis=
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earliest phase of formation of angioblasts from the
primitive mesenchymal precursors |
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Angiogenesis=
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early phase of formation of vessels from angioblasts (angioblasts to endothelial vessels)
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circulation pathway of embryo and indicate primitive hemopoeitic sites
start from primitive heart *=primitive hemopoesis |
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is placenta source of HSC
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yes
*has hemangioblasts gets HSC also from AGM |
