Genetic Engineering Why and how do we manipulate genetics?

Been done for ages Genetic engineering has been done since man first domesticated the dog –Selective breeding: picking animals or plants with desired traits and making them breed in order to highlight that specific trait –Inbreeding brings out the traits even faster….but has genetic downfalls

PCR techniques PCR: polymerase chain reaction –A way of making multiple copies of a particular sequence of DNA –Enzymes replicate the DNA without the use of living cells

Movement in a gel Gel electrophoresis separates out DNA fragments by size and electric charge Fragments move from the negative charge to the positive charge

DNA profiling Also known as DNA fingerprinting Compares DNA from different sources without mapping the entire genome –Used to compare evidence from crime scenes to suspects –Can also be used to determine paternity

Application of DNA profiling Forensic Investigations –Used to match DNA found at a crime scene with DNA from suspect Identification of Remains –Can be used to determine the identity of unknown remains by comparing the DNA from the body to a relative –Looks at DNA patterns that are inherited

Application of DNA profiling Paternity Cases –Based on the concept that a child’s DNA comes from the parents –Each band on the gel must correspond with a band from the mother or the father

Analyzing the results So….did he do it???

Universal Genetic Code The genetic code is the same between species –AUG is the start codon whether it be for a mouse or an elephant Allows genes from one species to be introduced into another species –Human gene for insulin can be put into a bacteria and the bacteria then produce human insulin

Gene Transfer Vectors carry the gene into a host cell The host cell is often bacteria –The genetic information is a large circle of DNA called a plasmid –The new gene is spliced into a plasmid and transferred into a bacteria cell –Bacteria is then cultured (increases the number) Restriction enzymes then cut out the desired DNA –Produced naturally by bacteria cells: prevents attack by some viruses –Ends up with an uneven cut of the DNA: left with sticky ends DNA ligase sticks the DNA fragment into the host DNA using the sticky ends

Uses of genetically modified stuff Called GM – as in GM crops – genetically modified crops Also called transgenic organisms Flavr Savr tomato –Genetically modified to stay fresh longer –A gene was added that blocked the production of the enzyme that causes rotting Bt Corn –A gene was added that makes the corn resistant to insects Golden rice –A gene is added that allows the rice to store vitamin A in the grains –A plus for people who suffered from vitamin a deficiencies

Closer look at BT corn Benefits –Damages caused by insects is greatly reduced –Less expensive than if pesticides are used –Less man power needed in the control of insects –Less insecticide used means less exposure for workers and the environment Harm –Will kill some insects –Insects are becoming resistant –Resistant insects are harder to kill with less damaging sprayed on insecticides –Spread of the genetic modification can not be contained

Outcomes of sequencing the human genome Improved understanding of many genetic disorders –Allows for genetic screening of these diseases –Downside is use by insurance companies to deny coverage Production of medicines to cure diseases or genetic engineering to remove the gene that causes disease Research can now be gene specific Provides evolutionary paths

Clone A genetically identical organism or a group of cells derived from a single cell

Cloning Technique Reproductive cloning creates a new individual –The nucleus from a somatic (body) cell is harvested –An egg is harvested and the nucleus of the egg is removed –The nucleus from the somatic cell is then transferred into the egg –An electric shock causes the cell to replicate –The embryo is now implanted into the uterus to grow into a new individual

Cloning Therapeutic Cloning –Stem cell research –Embryos are produced and allowed to grow into a small ball of unspecialized cells –Can develop into any type of tissue –Aim is to replace damage tissue with new tissue Like nerve cells Bone marrow Visual impairments

Ethical issues In favor of –Ability to cure disease Against –Fear of using the process for reproductive cloning –Creating and destruction of human embryos

Cloning or Not? ah.edu/content/clonin g/cloningornot/ ah.edu/content/clonin g/cloningornot/