Stem Cells!

Please have the cell differentiation ws out

different types of cells. 2- about 50 divisions from fertilized egg to adult billion cells make up the adult body 4- types of cells that continue to divide: skin, intestinal wall, blood (stem) cells, liver 5- cells that do not continue to divide: nerve,, kidney, heart, many others.

6a- a germ line is a cell line that, early in development, becomes differentiated from the somatic cell line and has the potential to form gametes. 6b- germ cells need to be separated early in development because they produce the gametes (sperm/egg). These gametes need to be unspecialized so they can eventually become the 230 specialized cells in the body. If you were even slightly differentiated then there would be issues in completing all of the 230 cells

7- Blastula is the stage before blastocyote. A blastula is a hollow ball of cells. A blastocyte is also a hollow ball but contains the inner mast cells or the embryoblast. The embryobast are the cells used for embryonic stem cell research.

8-Endoderm – Ectoderm – mesoderm

9- Once cells begin to differentiate even if they are not completely differentiated, they have some “programming” thus are not as viable as embryonic stem cells which are “clean slates” that can be “re-programmed” more easily.

Stem cell biology basics

A life story…

stem cell What is a stem cell? stem cell SELF-RENEWAL (copying) specialized cell e.g. muscle cell, nerve cell DIFFERENTIATION (specializing)

What is a stem cell? Identical stem cells Stem cell SELF-RENEWAL (copying) Stem cell Specialized cells DIFFERENTIATION (specializing)

1 stem cell Self renewal - maintains the stem cell pool 4 specialized cells Differentiation - replaces dead or damaged cells throughout your life Why self-renew AND differentiate? 1 stem cell

Where are stem cells found? embryonic stem cells blastocyst - a very early embryo tissue stem cells fetus, baby and throughout life

Types of stem cell: 1) Embryonic stem cells

Embryonic stem (ES) cells: Where we find them embryonic stem cells taken from the inner cell mass culture in the lab to grow more cells fluid with nutrients

Embryonic stem (ES) cells: What they can do embryonic stem cells PLURIPOTENT all possible types of specialized cells differentiation

neurons grow under conditions B Embryonic stem (ES) cells: Challenges embryonic stem cells skin grow under conditions A blood grow under conditions C liver grow under conditions D ?

Types of stem cell: 2) Tissue stem cells

Tissue stem cells: Where we find them muscles skin surface of the eye brain breast intestines (gut) bone marrow testicles

Tissue stem cells: What they can do MULTIPOTENT blood stem cell found in bone marrow differentiation only specialized types of blood cell: red blood cells, white blood cells, platelets

Types of stem cell: 3)Induced pluripotent (iPS) stem cells

Today's videos examines embryonic stem cell research, cloning, and the ethics surrounding the use of embryonic stem cells in the recent past pbs.org/wgbh/nova/sciencenow/3209/04.html 2004 pbs.org/wgbh/nova/sciencenow/3209/04.html pbs.org/wgbh/nova/sciencenow/3302/06.html 2006 pbs.org/wgbh/nova/sciencenow/3302/06.html Qw 2012 ips cells Qw

Induced pluripotent stem cells (iPS cells) cell from the body ‘genetic reprogramming’ = add certain genes to the cell induced pluripotent stem (iPS) cell behaves like an embryonic stem cell Advantage: no need for embryos! all possible types of specialized cells culture iPS cells in the lab differentiation

Induced pluripotent stem cells (iPS cells) cell from the body (skin) genetic reprogramming pluripotent stem cell (iPS) differentiation

Stem cell jargon Potency A measure of how many types of specialized cell a stem cell can make Pluripotent Can make all types of specialized cells in the body Embryonic stem cells are pluripotent Multipotent Can make multiple types of specialized cells, but not all types Tissue stem cells are multipotent

Cloning

There are two VERY different types of cloning: Reproductive cloning Use to make two identical individuals Very difficult to do Illegal to do on humans Molecular cloning Use to study what a gene does Routine in the biology labs gene 1 gene 2

Reproductive cloning remove nucleus and take the rest of the cell egg take the nucleus (containing DNA) cell from the body Clone identical to the individual that gave the nucleus Dolly the sheep

Molecular cloning: Principles gene 1 gene 2 2) Make a new piece of DNA gene 1 gene 2 1) Take DNA out of the nucleus cell 1cell 2 gene 1 gene 2 3) Put new DNA into a test cell and grow copies gene 1 cell divides Daughter cells contain same DNA: Genes 1 and 2 have been cloned gene 2 insert new DNA

Molecular cloning: Applications Normal mouse embryo gene A missing remove a gene to see if anything works differently Loss of function gene is involved in giving the eye its colour eye Reporter gene add a gene that shows us when another gene is working gene is active in blue areas only Lineage tracing mark a group of cells to see where their daughter cells end up gene is passed on to cells all over the body

-r0 BBC stem cell -r0 HW: tissue review packet and animal tissue worksheet, has tissue engineering in it