© 2015 Pearson Education, Inc. PowerPoint Lectures Campbell Biology: Concepts & Connections, Eighth Edition REECE TAYLOR SIMON DICKEY HOGAN Chapter 11 Lecture by Edward J. Zalisko How Genes Are Controlled

© 2015 Pearson Education, Inc. Learning Objectives 1.Explain how nuclear transplantation can be used to clone animals. 2.Describe some of the practical applications of reproductive cloning and the process and goals of therapeutic cloning.

© 2015 Pearson Education, Inc. CLONING OF PLANTS AND ANIMALS

© 2015 Pearson Education, Inc Plant cloning shows that differentiated cells may retain all of their genetic potential When cells undergo differentiation, they become specialized in structure and function, with each type of cell fulfilling a different role In plants, a differentiated cell can undergo cell division and give rise to all the tissues of an adult plant.

© 2015 Pearson Education, Inc Plant cloning shows that differentiated cells may retain all of their genetic potential When the cells from a carrot are transferred to a culture medium, a single cell can divide and grow into an adult plant. On a larger scale, this technique can be used to produce hundreds or thousands of genetically identical plants from the cells of a single plant. Such an organism, produced through asexual reproduction from a single parent, is called a clone. The term clone refers to an individual created by asexual reproduction.

© 2015 Pearson Education, Inc SCIENTIFIC THINKING: Biologists can clone animals via nuclear transplantation Animal cloning can be achieved using nuclear transplantation. In this process, the nucleus of an egg cell or zygote is replaced with a nucleus from an adult somatic cell. About 5 days after transplantation, repeated cell divisions form a blastocyst, a hollow ball of about 100 cells. If the animal being cloned is a mammal, the blastocyst is then implanted into the uterus of a surrogate mother. This type of cloning is called reproductive cloning because it results in the birth of a new living individual.

© 2015 Pearson Education, Inc SCIENTIFIC THINKING: Biologists can clone animals via nuclear transplantation Click and Clone: ckandclone/ ckandclone/

© 2015 Pearson Education, Inc SCIENTIFIC THINKING: Biologists can clone animals via nuclear transplantation Nuclear transplantation was first performed in the 1950s using cells from frog embryos. It was first used in mammals in 1996 to produce the sheep Dolly. Dolly demonstrated that the differentiation of animal cells is achieved by changes in gene expression, rather than by permanent changes in the genes themselves. Researchers have since cloned many other mammals, including mice, cats, horses, cows, mules, pigs, rabbits, ferrets, and dogs.

© 2015 Pearson Education, Inc CONNECTION: Therapeutic cloning can produce stem cells with great medical potential A blastocyst can provide embryonic stem cells (ES cells), which can differentiate in an embryo to give rise to all the specialized cell types of the body or divide indefinitely when grown in laboratory culture. When ES cells are use in therapeutic treatments, this process is called therapeutic cloning. The goal is to supply cells for the repair of damaged or diseased organs.

© 2015 Pearson Education, Inc. Figure Blood cells Nerve cells Heart muscle cells Different types of differentiated cells Different culture conditions Cultured embryonic stem cells Adult stem cells in bone marrow Embryonic stem cells removed from blastocyst

© 2015 Pearson Education, Inc CONNECTION: Therapeutic cloning can produce stem cells with great medical potential The adult body also has stem cells, which serve to replace nonreproducing specialized cells as needed. Because adult stem cells are farther along the road to differentiation than ES cells, they can give rise to only a few related types of cells.

© 2015 Pearson Education, Inc. This American Life: Cloning

© 2015 Pearson Education, Inc. Figure 11.UN02 Clone of the donor Surrogate mother An early embryo resulting from nuclear trans- plantation Nucleus from a donor cell Egg cell or zygote with nucleus removed

© 2015 Pearson Education, Inc. Figure 11.UN03 An early embryo resulting from nuclear trans- plantation Nucleus from a donor cell Egg cell or zygote with nucleus removed Embryonic stem cells in culture Specialized cells