C13- Genetic Technology Pp. 336 - 365

Contents 13.1 Applied Genetics 13.2 Recombinant DNA Technology 13.3 The Human Genome

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Applied Genetics Selective Breeding- choosing organisms with the most desired traits to serve as parents of the next generation.

Applied Genetics Inbreeding- mating closely related individuals; results in homozygous offspring Animal breed Plant cultivar

Applied Genetics Hybrids increase productivity and disease resistance in crops Usually larger and stronger than purebred parents Hybrid sorghum

Determining Genotypes Test Crosses- unknown genotype X known genotype Offspring ratios indicate genotype of unknown parent Homozygous dominant if 100% heterozygote Heterozygous if 1:1 ratio P. 340

13.2 Recombinant DNA Technology Genetic Engineering faster & more reliable method to increase the frequency of allele Involves cutting DNA from one organism & inserting it in another Recombinant DNA Technology

Recombinant DNA Technology Transgenic organism has foreign DNA Tobacco plant with firefly DNA

Recombinant DNA Technology Three step process

Recombinant DNA Technology Step 1- isolate foreign DNA fragment to be inserted Step 2- attach DNA fragment to a carrier Step 3- transfer into host organism

Restriction Enzyme Cleaves DNA Restriction enzymes bacterial proteins with ability to cut DNA sequence at specific nucleotide sequence Palindromes-same sequence in opposite orders Hundreds of restriction enzymes Fragments have sticky ends

Vectors Transfer DNA Carrier that transports foreign DNA into host Here a retrovirus serves as vector for engineered bone cells. Can be biological or mechanical Bacterial plasmid is a small ring of DNA Micropipette or DNA coated bullet from a gene gun ML 13.1, p. 343

Gene Cloning Clones are genetically identical copies Each identical recombinant DNA molecule is called a gene clone. Recombinant DNA can be inserted in yeast, plant cells and animal cells.

Animal Cloning Dolly the sheep first cloned animal, 1997 Dewey, first cloned deer, 2003

Polymerase Chain Reaction PCR method to replicate DNA outside an organism Thermocycler uses heat to separate DNA strands Enzyme used to repeatedly replicate DNA Used in crime investigations and diagnosis of infectious disease

Sequencing DNA Sequencing DNA allows scientists to identify mutations Four tubes A, C, T & G tagged with different colors Strands separated by size using gel electrophoresis

Applications of DNA Technology Industrial Produce chemical compounds Indigo for dye Cheese production Laundry detergent Pulp & paper products Sewage treatment

Applications of DNA Technology Medical Production of proteins Human growth hormone Insulin Antibodies Enzymes

Applications of DNA Technology Agriculture Crop development Insect resistance Genetically modified crops Vitamin fortified food Allergy reduction

13.3 The Human Genome In 2003 scientists in the Human Genome Project obtained the DNA sequence of 3 billion base pairs making up the human genome. It is nearly the same (99.9%) in all people.

13.3 The Human Genome Only about 2% of the human genome contains genes which are the instructions for making proteins. Humans have about 30,000 genes; the functions of more than half of them are unknown.

13.3 The Human Genome Almost half of human proteins share similarities with other organisms, underscoring the unity of life. Much is still unknown!

The Human Genome Genetic map that gives the relative location of genes on a chromosome is called a linkage map. Crossover occurs during prophase I of meiosis. Genes that crossover frequently must be farther apart.

The Human Genome Biotechnology increases the efficiency of mapping with new methods such as polymerase chain reaction (PCR) to make millions of copies of DNA fragments

The Human Genome Sequencing the human genome: 1) cleaving DNA into fragments 2) cloning fragments 3) sequences aligned All automated

Applications Diagnosis of genetic disorders Can be diagnosed before birth using amniotic fluid Isolating DNA Using PCR to analyze

Applications Gene Therapy Insertion of normal genes into human cells to correct genetic disorders SCID, cystic fibrosis, sickle cell anemia, hemophilia

Applications New Methods of Crime Detection DNA fingerprints from non-coding DNA segments unique to individual Can be used even with ancient DNA such as mummies or historical figures