Biotech II Lecture 19 - Embryonic Stem Cells

what kind of division do stem cells go through

asymmetric division

what is asymmetric division

when a stem cell divides into two different daughter cells

what are the two types of daughter cells that arise from stem cells

progenitor cell and self-renewal stem cell

what two distinct abilities do stem cells have

proliferation and differentiation

what is differentiation

the process where a cell becomes a specialized cell

what is proliferation

the process of a cell dividing into two cells

what is cell division

another name for proliferation where a cell divides into two

what happens to the cell during proliferation

goes through the cell cycle (M, G1, S, G2)

what happens to the cell during differentiation

cell exits the cell cycle and can remain in a G0 phase

what do disease or injuries do at a cellular level

1. too much cell division (tumors)

2. abnormal cell function (hemophilia don’t produce clotting factors)

3. too little cell division (spinal cord injury(neurons), weakened heart muscles)

traditional treatments for human disease or injury

pharmacologic intervention or surgery

newer ideas for renewal of damaged tissue

stem cell therapy

some benefits of stem cells in medicine

more individualized treatments, more opportunities for disease research

stem cells are important for new cells because they serve as what

a reservoir for new cells needed to replace damaged or dying cells

stem cells have a long lasting ability to do what when called upon

to multiply

pluripotent

stem cells that can give rise to all cells in the body

multipotent

stem cells that can give rise to multiple cell types in the body

unipotent

stem cells that can give rise to one cell type

totipotent

can give rise to all cell types in addition to extraembryonic tissue (placenta and yolk sac)

what type of potency are adult stem cells

multipotent or unipotent

ex. hematopoietic stem cells are multi and spermatogonial are unipotent

what type of potency are fetal stem cells from fetal tissue and progenitor stem cells

multipotent

what type of potency are umbilical cord stem cell

multipotent or pluripotent

what are somatic cell nuclear transfer (SCNT) stem cells

pluripotent stem cells where the nucleus from a somatic cell (fibroblast) is removed and transferred into the enucleated egg from an oocyte where the nucleus was removed

what does the egg from the oocyte and somatic cell develop into

blastocyst

what are induced pluripotent stem cells (iPS) cells

pluripotent stem cell derived in the lab from non-stem cells (somatic cells, such as fibroblasts)

parthenogenetic stem cells

pluripotent stem cells that came from unfertilized egg activated in vitro into a blastocyst

(lmao so women can reproduce on their own w/o yall lame ahh bums)

what are the potencies of most stem cells in adult body compared to stem cells in the blastocyst of the developing embryo

adult body: multipotent

blastocyst: pluripotent

what are embryonic stem cells (ES cells)

pluripotent stem cells isolated from a blastocyst (early stage embryo)

embryogenesis

es cells come from early stage embryos (blastocyst)

embryogenesis stems

A. Ovulated oocyte

B. Fertilization

B-C. Zygote forms, then male and female pronuclei fuse

D-G. Cleavage

H. Morula → blastula

I. Blastocyst formation followed by implantation

what does the blastocyst consist of

inner call mass (ICM) - pluripotent stem cells, trophoblast, blastocoele

what does the blastocyst do to the uterine lining

invades it and develops a gastrula by day 16

where does all tissue in the body come from

the inner cell mass (ICM) of the blastocyst

what does the ICM of the blastocyst develop into

gastrula

3 germ layers of gastrula and their functions

1. endoderm - forms soft tissues (pancreas, liver)

2. mesoderm - becomes muscle, blood, bone

3. ectoderm - forms the skin and nerve cells

potency of gastrula

multipotent (unlike pluripotent ICM)

how do you isolate es cells

fertilization of egg → development into a blastocyst → isolation of ICM cells of blastocyst → culture the cells → cells differentiate along different lineages

es cells have the ability to do what

proliferate and differentiate into specialized cell types