progenitor cell

(noun)

a biological cell that, like a stem cell, has a tendency to differentiate into a specific type of cell, but is already more specific than a stem cell and is pushed to differentiate into its "target" cell.

Related Terms

Examples of progenitor cell in the following topics:

  • Cellular Differentiation

    • Three basic categories of cells make up the mammalian body: germ cells, somatic cells, and stem cells.
    • Pluripotent stem cells undergo further specialization into multipotent progenitor cells that then give rise to functional cells.
    • Examples of stem and progenitor cells include:
    • Epithelial stem cells (progenitor cells) that give rise to the various types of skin cells
    • Muscle satellite cells (progenitor cells) that contribute to differentiated muscle tissue

  • Gene Expression in Stem Cells

    • In adult organisms, stem cells and progenitor cells act as a repair system for the body by replenishing adult tissues.
    • Asymmetric division, on the other hand, produces only one stem cell and a progenitor cell with limited self-renewal potential.
    • Progenitors can go through several rounds of cell division themselves before terminally differentiating into a mature cell. .
    • This diagram illustrates stem cell division and differentiation, through the processes of (1) symmetric stem cell division, (2) asymmetric stem cell division, (3) progenitor division, and (4) terminal differentiation.
    • Stem cells are indicated by (A), progenitor cells by (B), and differentiated cells by (C).

  • Establishing Body Axes during Development

    • The neural tube patterns along the dorsal-ventral axis establish defined compartments of neural progenitor cells that lead to distinct classes of neurons.
    • Other factors shown to provide positional information to the neural progenitor cells include Fibroblast growth factors (FGF) and Retinoic Acid.
    • These cell types are specified by the secretion of Shh from the notochord (located ventrally to the neural tube), and later from the floor plate cells.
    • The different combinations of expression of transcription factors along the dorsal-ventral axis of the neural tube are responsible for creating the identity of the neuronal progenitor cells.
    • Summarize the mechanisms and cell types that establish the body axes

  • Cytotoxic T Lymphocytes and Mucosal Surfaces

    • Most cells in the blood are red blood cells.
    • Recall that cells of the immune system originate from stem cells in the bone marrow.
    • B cell maturation occurs in the bone marrow, whereas progenitor cells migrate from the bone marrow and develop and mature into naïve T cells in the organ called the thymus.
    • Lymph nodes scattered throughout the body house large populations of T and B cells, dendritic cells, and macrophages .
    • The spleen houses B and T cells, macrophages, dendritic cells, and NK cells .

  • Skeletal Muscle Fibers

    • The highly specialized structure of myocytes has led to the creation of terminology which differentiates them from generic animal cells.
    • Each myocyte contains multiple nuclei, due to their derivation from multiple myoblasts (a progenitor cell that gives rise to myocytes), which are located to the periphery of the myocyte and flattened so as not to impact myocyte contraction.
    • A skeletal muscle cell is surrounded by a plasma membrane called the sarcolemma with a cytoplasm called the sarcoplasm.

  • Cell Theory

    • Cell theory states: living things are composed of one or more cells; the cell is the basic unit of life; cells arise from existing cells.
    • The unified cell theory states that: all living things are composed of one or more cells; the cell is the basic unit of life; and new cells arise from existing cells.
    • "All cells only arise from pre-existing cells.
    • Cells carry genetic material passed to daughter cells during cellular division
    • The cell is the basic unit of life and the study of the cell led to the development of the cell theory.

  • The Role of the Cell Cycle

    • In other words, that original single cell is the ancestor of every other cell in the body.
    • Single-celled organisms use cell division as their method of reproduction.
    • While there are a few cells in the body that do not undergo cell division, most somatic cells divide regularly.
    • A somatic cell is a general term for a body cell: all human cells, except for the cells that produce eggs and sperm (which are referred to as germ cells), are somatic cells.
    • The cell cycle is an ordered series of events involving cell growth and cell division that produces two new daughter cells.

  • Natural Killer Cells

    • After a pathogen enters the body, infected cells are identified and destroyed by natural killer (NK) cells, which are a type of lymphocyte that can kill cells infected with viruses or tumor cells (abnormal cells that uncontrollably divide and invade other tissue).
    • As such, NK cells offer a complementary check for unhealthy cells, relative to T cells.
    • NK cells are always active; an interaction with normal, intact MHC I molecules on a healthy cell disables the killing sequence, causing the NK cell to move on.
    • After the NK cell detects an infected or tumor cell, its cytoplasm secretes granules comprised of perforin: a destructive protein that creates a pore in the target cell.
    • Phagocytic cells then digest the cell debris left behind.

  • Regulation of the Cell Cycle by External Events

    • External factors can influence the cell cycle by inhibiting or initiating cell division.
    • Each cell is produced as part of its parent cell.
    • Some cells do live longer than others, but eventually all cells die when their vital functions cease.
    • Crowding of cells can also inhibit cell division.
    • Another factor that can initiate cell division is the size of the cell; as a cell grows, it becomes inefficient due to its decreasing surface-to-volume ratio.

  • Mechanics of Cellular Differentation

    • How does a complex organism such as a human develop from a single cell—a fertilized egg—into the vast array of cell types such as nerve cells, muscle cells, and epithelial cells that characterize the adult?
    • A multipotent stem cell has the potential to differentiate into different types of cells within a given cell lineage or small number of lineages, such as a red blood cell or white blood cell .
    • Finally, multipotent cells can become further specialized oligopotent cells.
    • Adult bone marrow has three distinct types of stem cells: hematopoietic stem cells, which give rise to red blood cells, white blood cells, and platelets ; endothelial stem cells, which give rise to the endothelial cell types that line blood and lymph vessels; and mesenchymal stem cells, which give rise to the different types of muscle cells.
    • The multipotent hematopoietic stem cells give rise to many different cell types, including the cells of the immune system and red blood cells.