stem cells

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stem cells
2013-11-04 00:03:31

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  1. What
    is in vitro fertilization?
    • In the IVF procedure, sperm and eggs
    • “interact” in a dish leading to insemination.

    • They literally swim up to the egg and
    • burrow toward the nucleus.

    • The first one to get there wins, and
    • all others are blocked out.
  2. What
    is a morula? At approximately how many days of human development is it?
    • On day 4, the cells
    • have divided several times more and are indistinct. They’re still identical.
  3. What
    is a blastocyst? At approximately how many days of human development is it?
    • Day 5 is a big day.
    • Now, fluid builds up inside the ball of cells, making it look hollow like a
    • soccer ball. This structure is called a blastocyst. 
    • No, they are not.. The outer layer of the blastocyst is made up of cells that are destined to become the
    • placenta. There is a clump of cells sitting inside the blastocyst, that is destined to
    • become the fetus. However, this is definitely not a fetus yet.
  4. Which
    part of the blastocyst will give rise to the placenta (name that layer)? Which
    part will give rise to the embryo?
    • •Blastocyst has
    • a thin outer layer of cells called the trophoblast
    • –Will later form the placenta
    • •Inner cell mass will develop into the fetus.
    • •A blastocyst contains approximately 120 cells
  5. What
    are the three germ layers of a developing embryo? What are some tissue types
    that are developed from each germ layer?
    • Endoderm
    • Thymus 
    • Thyroid,
    • parathyroid glands
    • Larynx,
    • trachea, lung
    • Urinary
    • bladder, vagina, urethra
    • Gastrointestinal
    • (GI) organs (liver, pancreas)
    • Lining
    • of the GI tract
    • Lining
    • of the respiratory tract
    • Mesoderm
    • Bone marrow (blood)
    • Adrenal
    • cortex
    • Lymphatic
    • tissue
    • Skeletal, smooth, and
    • cardiac muscle
    • Connective tissues
    • (including bone, cartilage)
    • Urogenital system
    • Heart and blood vessels (vascular syste

    • Ectoderm
    • Skin
    • Neural tissue (neuroectoderm)
    • Adrenal
    • medulla
    • Pituitary
    • gland
    • Connective
    • tissue of the head and face
    • Eyes,
    • ears
  6. What
    are two properties of stem cells?
    • •Self-renewal
    • –the ability to go through numerous cycles of cell division
    • while maintaining the undifferentiated state of the cell
    • •Unlimited
    • potency
    • –the capacity to differentiate into any mature cell type
    • •stem cells can be totipotent
    • or pluripotent
    • •some multipotent and/or unipotent progenitor cells are referred to
    • as stem cells
  7. What
    is asymmetric cell division? What does this process achieve?
    When the stem cell divides, it gives rise to two cells that are different from each other.

    • One of the cells remains a stem cell, demonstrating self-renewal, and the other 
    • differentiates into a progenitor cell.
  8. Define
    totipotent, pluripotent, multipotent, and unipotent. Give an example of cells
    that exhibit each type of potency.
    • –Totipotent stem cells
    • •cells produced in the first few
    • divisions after fertilization of oocyte by
    • sperm
    • •capacity to differentiate into
    • embryonic and extraembryonic cell types
    • –Pluripotent stem cells
    • •descendants of totipotent cells (inner cell mass)
    • •ability to differentiate into
    • cells derived from any of the three germ layers
    • –endoderm, mesoderm, ectoderm
    • –Multipotent stem cells
    • •produce only cells of a closely
    • related family of cells
    • –hematopoietic stem cells
    • differentiate into WBCS, RBCs, platelets, etc.
    • –Unipotent cells
    • •produce only one cell type
    • •ability to self-renewal which
    • distinguishes them from non-stem cells
    • spermatogonial stem cells differentiate into spermatozoans
  9. What
    are two sources of embryonic stem cells? Know in general how each procedure is carried
    out and how the two procedures differ.
    • •In Vitro Fertilization (embryonic stem cells)
    • •Nuclear Transfer (embryonic stem cells)
  10. What
    are adult stem cells? How are they different from embryonic stem cells? In
    which organ do adult stem cells reside?
    • •An adult stem cell is an undifferentiated (or partially-differentiated) cell found in
    • tissues and organs
    • •They can self-renew and differentiate to become most or all of the specialized cell types within their specific tissue
    • lineage.
    • •Adult stem cells
    • –Maintain cell populations
    • –Help you heal
    • Play a role in aging
    • •Blood
    • •Skin
    • •Lining of gut
    • •Liver
    • Muscle
  11. What
    are the four types of adult stem cells? To which differentiated cell types does
    each give arise?
    • Hematopoietic stem cells: blood and immune
    • system 
    • Mesenchymal
    • stem cells: bone, cartilage, fat, muscle, tendon/ligament
    • Neural stem cells: neurons, glial
    • cells
    • Epithelial stem cells: skin, linings
  12. What
    are induced pluripotent stem cells? How do you generate them? Why would the
    production of such cells be important in stem cell research?
    • •iPS cells are a type of pluripotent
    • stem cell
    • –Artificially derived from a non-pluripotent
    • cell (adult somatic cell)
    • –Inducing a “forced” expression of specific pluripotency genes
    • •Oct-3/4, SOX2, c-Myc, and
    • Klf4
    • –C-Myc is oncogenic and caused 20% of the chimeric mice to develop cancer
    • –obtain pluripotent stem cells without using embryos
    • •Isolate/culture donor
    • cells
    • •Transfect cells with stem
    • cell-associated genes using viral vectors (red cells express exogenous genes)
    • •Harvest and culture cells
    • on mitotically-inactivated
    • feeder cells
    • •A subset of transfected
    • cells become iPS
    • cells generating ES-like colonies
  13. What
    are needed to induce embryonic stem cells to differentiate into different
    Embryonic stem cells candifferentiate into different lineages given appropriate factors
  14. What
    are some uses of cultured pluripotent stem cells?
  15. Give
    one example of an adult stem cell therapy
    bone marrow transplant
  16. Why
    might one want to “bank” the umbilical cord blood cells? (see Notes section for
    slide 54.
    • Umbilical
    • cord, the tissue connecting baby to mother before birth, is a rich source of
    • hematopoietic (hee-mat-oh-poetic) stem
    • cells. The umbilical cord is usually thrown away after a baby is born, but some
    • people choose to “bank” the umbilical cord blood cells in case the child needs
    • to use those stem cells later on. Hematopoietic stem cells from umbilical cord
    • do not have the same immune-rejection issues as hematopoietic stem cells from
    • bone marrow, which makes them ideal for therapies.