Sorting and Analyzing DNA gel electrophoresis is used to separate molecules according to mass and charge used to separate fragments of DNA TO BEGIN Solution containing DNA is apllied to one end of a gel

electrophoresis Electric current is added so one end has positive and one end has a negative charge DNA is negative so will migrate toward positive end of the gel Smaller fragment move more quickly so will travel farther. Fragment form a pattern of bands called a DNA fingerprint

Restriction enzymes and gel elctrophoresis help researchers analyze and compare DNA samples Ex #1. Forensics (DNA sample from a crime scene can be cut with restriction enzymes and turned into a DNA fingerprint that can be compared to possible suspects DNA fingerprints to identify a match. Ex #2. Parentage.

Do a Venn Diagram for RNA and DNA

Genetics and Society Section 18.4

Biotechnology Using natural biological systems to create new technologies and products Computers store enormous amounts of genetic information (gene banks, DNA libraries) Potential to change the way we live: Diagnose and treat diseases, food, industries, air we breathe

PCR Polymerase Chain Reaction Used to make many copies of a specific strand of DNA VERY quickly! ANIMATION

Gathering and managing Genetic information DNA microarray Chip with a grid of thousands of microscopic cells Each cell contains a nucleic acid that can bind with one mRNA molecule transcribed during gene expression

The microarray is scanned and analyzed to compare the pattern of gene expression in each cell sample can analyze thousands of genes at the same time Genes in same cell in different environments Pinpoint genes reponsible for a particular function, interections among genes, relationship between envirnoment and gene expression ANIMATION

STEM CELLS Stem Cell School

Public Benefits of Genetic Research Human medicine Developing drugs tailored to particular gene expression associated with particular disorders and unique human genome All research about Human Gnome project is public

Ownership of Genetic Information Who owns volunteered DNA Genographic Project

Patenting organisms and genes Roundup-Ready canola Resistant to herbicide Roundup Patented by Monsanto, who controls how it can be used, so they can make a profit Concerned farmers What happens with breast cancer gene?

Biotechnology Products We know how to import foreign DNA into bacteria, when it is imported into plants and animals it produces a transgenic organism. Uses for biotechnology products…..

Medicinal Bacteria Human insulin synthesized by transgenic bacteria Why bacteria? Bioremediation – using living cells (bacteria) to clean up environment: oil spills, remove heavy metals from water, remove polychlorinated biphenyls (PCBs) from soil

Transgenic Plants ½ crop plants are transgenic to become more resistant to herbicides, insect pests, and viruses Plants can be more tolerant of drought and colder temperatures Higher yields Also can be more nutritious Ie. rice

Cloned and Transgenic Animals Clones- genetically identical (twins), arise naturally in nature Researcher Ian Wilmut successfully cloned a a sheep, Dolly, from and adult somatic cell. Clones have a higher mortality rate, high incidence of disease, premature aging, etc.

Cloning Genes Sometimes we clone genes and not more complex organisms Can you think of and example? ANIMATION

GMO”S

Transgenic Animals Goats can be made to secrete pharmaceutical products Goats can secrete human polypeptide in their milk Research trying to make animals viable organ donors for humans So far, limited success due to immune response in humans

Assessing the risks Transgenic products must be reviewed by government agencies for approval. Social, economic, and environmental cost and benefit Biological characteristics of transgenic vs natural plant Potential health effects, including that the product may contain toxins or allergens

Risks Cited Environmental: Herbicide resistant crops  more herbicide used  contaminated water as well as “superweeds” and “superbugs” Health: not enough understood about genetically modified foods Social/economic: help provide food for the poor or wastes money on research?

Diagnosis and Treatment of Genetic Disorders Prenatal Diagnosis and Genetic Screening Ultrasound: sound waves sent through amniotic fluid bounce off the developing fetus and create a cross-sectional image Can reveal physical abnormalities

Amniocentesis: genetic makeup is found by sample tissue from the amniotic fluid in uterus Cells multiply and researchers prepare karyotype Can only be done after the 14 th week

Chorionic villi sampling 9 th week of pregnancy Sample taken from chorion (which are fetal cells) Can get a karyotype

Genetic markers A characteristic that provides information about the genotype of an individual Can be a sequence of nucleotides that is known to associate with, or be part of the gene of interest Can be found using a DNA probe

DNA Probe DNA molecule with a nucleotide sequence complimentary to marker sequence “marked” with a chemical tag DNA from sample is placed in suspension with probe If DNA sample contains gene of interest, probe will bind to the marker sequence Tag will verify presence or absence of gene

Treating Human Genetic Disorders Gene therapy: the process of changing the function of a gene in order to treat or prevent a genetic disorder Some disorders (diabetes, Parkinson’s) can be combated by targeting their genetic causes, rather than simply treating symptoms.

DNA Vector Carries foreign DNA into target cells in the patient. Often a modified form of virus Viruses can target specific cells and insert their DNA into the genomes of these cells Viruses can be genetically altered to carry a desired gene using restriction endonucleases

Risks with viral vectors Viral protein coat can trigger an immune response, including high fever and organ failure Some researchers fear virus may regain some pathogenic properties if it comes into contact with other viruses Due to risks, researchers are looking into artificial chromosomes as vectors

What is Gene Therapy? Link

Ethics Gene Therapy So far, mainly somatic gene therapy aimed at correcting genetic disorders in somatic cells Which may improve the health of a patient, but does not prevent disorder from being passed on to next generation

Germ-line Therapy More controversial, can modify information carried in egg or sperm cell. Theoretically, could eliminate inherited genetic disorders Realistically, could have unforeseen effects on future generations Currently-banned in Canada

Questions raised What genetic conditions are “disorders” that deserve treatment? How much control should parents have to “design” there child? Potential benefits must be balanced with public interest and beliefs.

Virtual labs Go to Search and do the following labs Gel Electrophoresis Click and Clone Space Doctor (at least one patient and 2 vectors) PCR Virtual Lab