1. Stem Cell Research Stem Cell Development Lesson 1
The Science and Ethics of
Stem Cell Research
Stem Cell Development
Lesson 1

2. Stem Cell Development
November 4, 2010

3. Warmup Which of the following is true of stem cells?
(COPY THE ENTIRE STATEMENT FOR THE STATEMENTS YOU THINK ARE TRUE)
Stem cells are able to make more of themselves by dividing
Stem cells can differentiate (give rise to daughter cells that can develop into many types of cells).
Adult human bodies contain roughly 20-30% stem cells.
The word multipotent is used to describe a cell that can become ANY other type of cell in an organism.

4. What will we learn about today?
Where are embryonic stem cells found?
How does their ability to differentiate change over time?

5. NOVA video Stem Cells: Early Research

6. Homework:
Review worksheet on back of the gold sheet

7. An Overview of Early Development modeled with Play-Dough
Fertilized egg
Totipotent
stem cells
Totipotent: Can become any cell in body or placenta
Fate Decision
Pluripotent
stem cells
(3-5 days old)
Blastocyst
Pluripotent: Can become any cell in body
Implantation
Fate Decision
Gastrulation (day 14) leads to
Primary Germ Cells
Endoderm (inner)gdigestive tract, resp. track
Mesoderm (middle)gbones, blood cells, heart
Ectoderm (outer)gskin, CNS
Multipotent: Can become any cell within a specific germ layer or cell lineage
Implantation
Fate Decision
Gastrulation (day 14) leads to
Primary Germ Cells
Endoderm (inner)gdigestive tract, resp. track
Mesoderm (middle)gbones, blood cells, heart
Ectoderm (outer)gskin, CNS
Multipotent: Can become any cell within a specific germ layer or cell lineage
Embryonic stem cells come from inner cell mass of blastocyst.
Multipotent

8. What your zygote might look like:

9. The Zygote

10. What your morula might look like:

11. Early Cell Division
Source: Florida Institute for Reproductive Science and Technologies

12. Four-cell stage 2 days after fertilization
Source: Florida Institute for Reproductive Science and Technologies

13. Eight-cell stage 3 days after fertilization
Courtesy: RWJMS IVF Program
Source: Florida Institute for Reproductive Science and Technologies

14. Morula 4 days after fertilization 16 cells
Source: Florida Institute for Reproductive Science and Technologies

15. What your blastula (blastocyst) might look like:

16. Blastula 5 days after fertilization
Source: Florida Institute for Reproductive Science and Technologies
Courtesy: RWJMS IVF Program

17. Five Day Embryo

18. Blastula (Blastocyst)
This image has been released into the public domain.

19. What your gastrula might look like:

20. Sea Urchin Development
One Cell to Blastula Stage
(courtesy of Dr. J. Hardin, Univ. of Wisconsin)

21. Early Mouse
Development
One Cell to Morula Stage

22. Early Human Development

23. Multipotent
This graphic has been released into the public domain