Embryo Cloning One embryo splits into 2 identical embryos May occur from 2 cell stage up to 14 days After 14 days results in conjoined twins Happens naturally and artificially

Natural Embryo Cloning 1 in 75 pregnancies spontaneously clone Blastula (ball of cells) splits in 1st 14 days Monozygotic twins = clones

Natural Triplets – 1 in 8,100 births Natural Quadruplets – 1 in 729,000 All quads - 1 in 571,787 Multiple Births Canada (MBC): 90% of quad pregnancies result from fertility assistance. At $100,000 a try The incidence of quad birth rose more than 400% in the last quarter of the 20th century

Dr. Papiernik said at his hospital, half the babies in neonatal intensive care are from fertility-enhanced pregnancies. The cost of such care has led countries with national health care like England and France to restrict the number of embryos placed during in vitro fertilization to three. Multiples spend up to 10 weeks in neonatal intensive care at $7,000 a day

Artificial Twinning Embryo cloning where embryos from desirable parents encouraged to spilt into clones. Embryos implanted into surrogate mothers. Ex. Genetically engineered low fat pork High quality beef cattle

Adult Cloning DNA from adult it placed in an egg Called Nuclear Transfer 1) nucleus of egg is removed 2) nucleus from adult cell placed in the egg 3) egg shocked (chemicals or electricity) 4) shocked egg reacts like it was fertilized 5) growing embryo implanted in surrogate mother.

Cloning 1 A microneedle 2 The microneedle has emptied the sheep egg of its own nucleus. 3 DNA from a donor cell is about to be deposited in the enucleated egg. 4 An electric spark will stimulate the egg to enter mitotic cell division. the first cloned sheep Fig. 13-9, p.214

Impacts, Issues: Goodbye Dolly Ian Wilmut was the first to produce a cloned sheep, which he named Dolly Dolly experienced health problems similar to other mammals cloned from adult DNA

Goodbye Dolly Fig. 13-1a, p.206

Impacts, Issues: Goodbye Dolly The risk of defects in clones is huge Possible benefit – patients in desperate need of organ transplants Genetically modified cloned animals may produce organs that human donors are less likely to reject Cloning humans – ethical?

Impacts, Issues Video D:\PowerLecture\Media\PowerLectures\chapter13\animations\csDolly.html Goodbye Dolly

D:\PowerLecture\Media\PowerLectures\chapter13\animations\csDolly.html

Cloning Making a genetically identical copy of an individual Researchers have been creating clones for decades These clones were created by embryo splitting

Cloning How Dolly was created

Dolly: Cloned from an Adult Cell Showed that differentiated cells could be used to create clones Sheep udder cell was combined with enucleated egg cell Dolly is genetically identical to the sheep that donated the udder cell

Dolly: Cloned from an Adult Cell Fig. 13-9, p.214

Cloning vs. Sexual Reproduction

More Clones Mice Cows Pigs Goats Guar (endangered species)

Fig. 13-10, p.215

Fig. 13-10, p.215

Therapeutic Cloning SCNT – Somatic Cell Nuclear Transfer Transplant DNA of an adult somatic cell into a stem cell (undifferentiated cell)

1: under the microscope, the DNA of the patient is introduced into the egg, through a microscopic glass tube. After 5-6 days, the egg has developed into a ball of cells, the blastocyst, of which is removed the inner cell mass. After culture in a plastic dish, the inner cell mass has grown to aggregates which contain the embryonic stem cells that match the patients immunologic profile.

Theraputic Cloning by Nuclear transfer of patients DNA

Cloned cells will not be rejected by the patient's immune system. These embryonic stem cells can now be used to generate cells and tissues for the patient.

Embryonic Stem Cells http://www.dnalc.org/resources/animations/stemcells.html Sources of stem cells…. unwanted embryos from fertility treatment Embryos created by nuclear transfer from egg

Congress twice passed the Stem Cell Research Enhancement Act with strong bipartisan support both times President Bush vetoed the bill. President Barack Obama lifted the restrictions on federal funding for ESCR on March 9, 2009 by an Executive Order. http://www.ncsl.org/IssuesResearch/Health/EmbryonicandFetalResearchLaws/tabid/14413/Default.aspx