Stem Cells

Cell Differentiation

Learning Objectives

Describe the process of differentiation. Define stem cells and explain their importance. Identify the possible benefits and issues relating to stem

cell research.

Defining Differentiation

During the development of an organism, cells differentiate tobecome .specialized

Store sugarTransport materials

Carry out photosynthesis

Mapping Differentiation

25 = 2? =

32

28

256

What Are Stem Cells?

Stem cells are the cells from which differentiated cells develop.

Totipotent: “can do everything”

Pluripotent: “can do most things”

unspecialized

Embryonic Stem Cells

embryonic stem cells

Adult Stem Cells

• Multipotent: “can do many things”

• Give rise to limited number of cell types

• Mainly found in bone marrow, hair follicles

• Also some in brain, heart, and skeletal muscle

Regenerative Medicine

Undifferentiated cells are used to repair or replace damaged cells and tissues.

Ethical Issues

•Human adult stem cell research is rarely controversial because of willing donors.

• Human embryonic stem cell research is controversial because arguments for and against involve ethical issues of life and death.

Cellular Reprogramming

• Induced Pluripotent Stem Cells (iPS)

• May ultimately help society reframe the debate over use of stem cells

Dr. Shinya Yamanaka