Stem cell research Bryan Spiegelberg x7651

True/False President Bush declared research on embryonic stem cells illegal in the U.S.

True/False Embryonic stem cell research is not funded by Federal money

True/False President Bush created new restrictions on the use of Federal funds for embryonic stem cell research.

True/False The widespread use of stem cells in medical treatments is a long way off.

True/False The widespread use of embryonic stem cells in medical treatments is a long way off.

True/False Most major religions officially oppose research on embryonic stem cells.

True/False It is necessary to destroy an embryo to obtain embryonic stem cells.

True/False Embryonic stem cell research might lead to human cloning.

“Cloning” Production of multiple genetically identical organisms

True/False Routine cloning of organisms is stuff of science fiction.

True/False OK, but higher organisms can’t be cloned.

Dolly ( ): genetically identical to her adult mother Since: mice, cats, pigs, cattle, rats…no primates, yet…

True/False No human clones exist.

True/False Most Americans support research on embryonic stem cells

ABC News poll: Legality of stem cell research: 58% pro/30% con Funding SCR: 60% pro/31% con

International Communications Research (ICR) poll Support stem cell research if it means an embryo is destroyed? 24% pro/70% con

CYTOPLASM -energy production -biomolecule factories -etc. NUCLEUS -genetic material: information storage -info helps define cell’s characteristics shape, rate of growth, etc.

Nucleus/Genetic information –Link between a cell and its ancestor Information: DNA → book chromosomes → chapters genes → words

DNA vs. Proteins Words → don’t mean much without action PROTEINS → main actors derived from and taking direction from the DNA Individuality derives ultimately from the DNA

Cells → Tissues → Organs → Organisms ~ trillion (10 14 ) total cells in your average human ~200 types of specialized cells Blood cells Neuron

Blood cells/neurons, etc. are terminally differentiated (a.k.a. post-mitotic) –Typically stop dividing/growing Focus on specialty –When lost → damage/old age Often need to be replaced: How? “Like” cells dividing OR Stem cell progenitors ADULT Stem Cells: Why?

STEM CELL Undifferentiated Cell division TWO DAUGHTER CELLS Two different fates 1.UNDIFFERENTIATED Self-renewal 2.DIFFERENTIATED Replace lost cell

Stem cells by definition 1.Non-terminally differentiated cell that can give rise to specialized cells 2.Able to divide without limit 3.Self-renewal: Undergo asymmetric cell division

A: Stem cell B: Progenitor cell C: Specialized cell

Single cell → Fertilized egg/zygote 10 trillion adult cells PROLIFERATION 200 specialized types of cells SPECIALIZATION EMBRYONIC Stem Cells: What? Why?

+ FERTILIZED EGG Is it “human”? Nervous system Skin cells Germ cells Placenta etc. Founding cell must be a totipotent stem cell

Totipotent: unlimited potency Able to generate all cells of the developing organism: placenta, somatic cells, germ line Pluripotent: some loss of potency eg. potential progenitor of somatic cells, germ line, but not the placenta Multipotent: limited potency only generate related specialized cells eg. hematopoietic stem cells differentiate into red/white blood cells, platelets, etc. Unipotent: generate a single type of cell (but still self-renewing)

Development ZYGOTE MORULA BLASTOCYST (internal cavity) 2-3 days in mice

Blastocyst INNER CELL MASS toti/pluripotent TROPHECTODERM placenta UTERINE WALL mom BLASTOCOEL

Inner cell mass: highly potent Formation of a teratoma upon injection –“monster tumor” –disorganized differentiation upon implantation Skin, bones, glandular tissues, hair, etc.