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Directed Differentiation of Primitive and Definitive Hematopoietic Progenitors from Human Pluripotent Stem Cells
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Published on: November 1, 2017

Early origins of definitive erythroid cells in the chick embryo

I Dardick, G Setterfield

    Tissue & Cell
    |January 1, 1978
    PubMed

    Insights

    Definitive erythroid cells in chick embryos originate from early precursors in the yolk sac. These cells mature within sinusoids before entering the embryonic circulation.

    Area of Science:

    • Developmental biology
    • Hematopoiesis
    • Embryology

    Background:

    • Erythropoiesis is the process of red blood cell production.
    • Definitive erythroid cells are crucial for oxygen transport in vertebrates.
    • Understanding early erythroid development is key to developmental biology.

    Purpose of the Study:

    • To investigate the origin and early maturation of definitive erythroid cells in chick embryos.
    • To identify the timing and location of definitive erythroid cell precursor development.
    • To describe the cellular dynamics of erythroblast development within the yolk sac.

    Main Methods:

    • Light microscopy of chick yolk sac membrane.
    • Electron microscopy of yolk sac mesoderm.
    • Observation of embryonic circulation during incubation.

    Main Results:

    • Definitive erythroid cell precursors identified in yolk sac mesoderm by day 2 of incubation.
    • Immature erythroblasts form sequestered populations within sinusoids between days 2.5-6.
    • Erythroblasts initially associate with endothelium before entering free circulation.

    Conclusions:

    • Early precursors for definitive erythroid cells are present by day 2 of chick embryonic development.
    • Yolk sac sinusoids serve as sites for erythroblast maturation and sequestration.
    • The transition to free circulation involves association with endothelial cells.

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