Cell Transformation, Transgenic Organisms &

Cloning

Cell Transformation, Transgenic Organisms, & Cloning

• Put DNA back into living cells

• Transformation – cell takes in DNA from outside the cell. This external DNA becomes part of the cell’s DNA

Transforming Plant Cells

• When cell walls removed, plant cells will sometimes take up DNA on their own

• DNA can also be injected into cells

• Cells transformed by either process can be cultured to produce adult plants

• If transformation is successful, the recombinant DNA is integrated into one of the chromosomes of cell

Transforming Animal Cells

• Can be transformed in some of same ways as plant cells

• Egg cells large enough to inject DNA

• Enzymes responsible for DNA repair (DNA Polymerase) help to insert foreign DNA into chromosomes

• Through transformation, it is possible to replace genes

Transgenic Organisms & Cloning

• Organisms that contain genes from other organisms using transformation techniques = transgenic organism

Transgenic Plants

• Important part of food supply

• Genetically modified foods – 45% of corn grown in US

• Plants contain a natural insecticide or resist weed-killing chemicals

• May soon produce human antibodies to help fight disease

Transgenic Animals

• Study genes and improve food supply

• Growth hormone gene in livestock to grow faster and produce less fatty meat

• May soon produce supply of human proteins in milk

Cloning

• Clone is a member of a population of genetically identical cells produced from a single cell

• Nucleus of egg removed and fused with a cell from another organism. Fused cell divides and embryo placed into a foster mother

• May find use in medical and scientific research, but raises serious ethical issues…

Cloning

A body cell is taken from a donor animal.

An egg cell is taken from a donor animal.

The fused cell begins dividing, becoming an embryo.

The nucleus is removed from the egg.

The body cell and egg are fused by electric shock.

The embryo is implanted into the uterus of a foster mother.

The embryo develops into a cloned animal.

CloningA donor cell is taken from a sheep’s udder. Donor

Nucleus

These two cells are fused using an electric shock.

Fused Cell

The fused cell begins dividing normally.

EmbryoThe embryo is placed in the uterus of a foster mother.Foster

Mother

The embryo develops normally into a lamb—Dolly

Cloned Lamb

Egg Cell

An egg cell is taken from an adult female sheep.

The nucleus of the egg cell is removed.

Cloning