Stem Cell Development

Lesson 1

The Science and Ethics of Stem Cell Research

An Overview of Early Development modeled with Play-Dough

Fertilized egg

Totipotentstem cells

Totipotent: Can become any cell in body or placenta

Fate Decision

Pluripotentstem cells(3-5 days old)

Blastocyst

Pluripotent: Can become any cell in body

Implantation

Fate DecisionGastrulation (day 14) leads toPrimary Germ CellsEndoderm (inner)digestive tract, resp. trackMesoderm (middle)bones, blood cells, heartEctoderm (outer)skin, CNS

Multipotent: Can become any cell within a specific germ layer or cell lineage

Embryonic stem cells come from inner cell mass of blastocyst.

Implantation

Fate DecisionGastrulation (day 14) leads toPrimary Germ CellsEndoderm (inner)digestive tract, resp. trackMesoderm (middle)bones, blood cells, heartEctoderm (outer)skin, CNS

Multipotent: Can become any cell within a specific germ layer or cell lineage

Multipotent

What your zygote might look like:

The Zygote

What your morula might look like:

Early Cell Division

Source: Florida Institute for Reproductive Science and Technologies

Four-cell stage 2 days after fertilization

Source: Florida Institute for Reproductive Science and Technologies

Eight-cell stage3 days after fertilization

Courtesy: RWJMS IVF Program

Source: Florida Institute for Reproductive Science and Technologies

Morula 4 days after fertilization 16 cells

Source: Florida Institute for Reproductive Science and Technologies

What your blastula (blastocyst) might look like:

Blastula5 days after fertilization

Courtesy: RWJMS IVF Program

Source: Florida Institute for Reproductive Science and Technologies

Five Day Embryo

http://www.nationalgeographic.com/ngm/

Blastula (Blastocyst)

This image has been released into the public domain.

What your gastrula might look like:

http://www.luc.edu/depts/biology/dev/urchindv.htm (courtesy of Dr. J. Hardin, Univ. of Wisconsin) http://www.exploratorium.edu/imaging_station/gallery.php?Asset=celldiv&Category=seaurchins&Type=video

Sea Urchin DevelopmentOne Cell to Blastula Stage

Early Mouse Development

One Cell to Morula Stage

Early Human Development

This graphic has been released into the public domain

Multipotent