-
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.
-
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.
-
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.
-
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
-
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
-
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
-
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.
-
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
-
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)
-
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
-
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
-
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
-
What
are needed to induce embryonic stem cells to differentiate into different
lineages?
Embryonic stem cells candifferentiate into different lineages given appropriate factors
-
What
are some uses of cultured pluripotent stem cells?
-
Give
one example of an adult stem cell therapy
bone marrow transplant
-
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.
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