DNA Technology and Genomics Chapter 12 DNA Technology and Genomics

DNA and Crime Scene Investigations DNA and Crime Scene Investigations Many violent crimes go unsolved For lack of enough evidence If biological fluids are left at a crime scene DNA can be isolated from them

DNA fingerprinting is a set of laboratory procedures DNA fingerprinting is a set of laboratory procedures That determines with near certainty whether two samples of DNA are from the same individual That has provided a powerful tool for crime scene investigators Investigator at one of the crime scenes (above), Narborough, England (left)

BACTERIAL PLASMIDS AND GENE CLONING 12.1 Plasmids are used to customize bacteria: An overview Plasmid-a small DNA molecule that is physically separate from, and can replicate independently of, the chromosomal DNA within a cell. Gene cloning is one application of DNA technology Methods for studying and manipulating genetic material

And insert those plasmids into bacteria Researchers can insert desired genes into plasmids, creating recombinant DNA And insert those plasmids into bacteria Bacterium 1 Plasmid isolated Cell containing gene of interest 2 DNA isolated 3 Gene inserted into plasmid Bacterial chromosome Plasmid Recombinant DNA (plasmid) DNA Gene of interest 4 Plasmid put into bacterial cell Recombinant bacterium 5 Cell multiplies with gene of interest Copies of gene Copies of protein Gene for pest resistance inserted into plants Clone of cells Protein used to make snow form at higher temperature Figure 12.1 Gene used to alter bacteria for cleaning up toxic waste Protein used to dissolve blood clots in heart attack therapy

If the recombinant bacteria multiply into a clone The foreign genes are also copied

CONNECTION 12.6 Recombinant cells and organisms can mass-produce gene products Applications of gene cloning include The mass production of gene products for medical and other uses Table 12.6

Different organisms, including bacteria, yeast, and mammals Different organisms, including bacteria, yeast, and mammals Can be used for this purpose Figure 12.6

12.7 DNA technology is changing the pharmaceutical industry CONNECTION 12.7 DNA technology is changing the pharmaceutical industry DNA technology Is widely used to produce medicines and to diagnose diseases

Therapeutic hormones In 1982, humulin, human insulin produced by bacteria Became the first recombinant drug approved by the Food and Drug Administration Figure 12.7A

Diagnosis and Treatment of Disease Diagnosis and Treatment of Disease DNA technology Is being used increasingly in disease diagnosis

Vaccines DNA technology Vaccines DNA technology Is also helping medical researchers develop vaccines Figure 12.7B

Vaccine Vaccine-a substance containing all or part of a harmless version of a pathogen that physicians introduce into the body to produce immunity to disease.

12.12 DNA technology is used in courts of law CONNECTION 12.12 DNA technology is used in courts of law

DNA fingerprinting can help solve crimes DNA fingerprinting can help solve crimes Blood from defendant’s clothes Defendant’s blood Victim’s blood Figure 12.12A Figure 12.12B

CONNECTION 12.13 Gene therapy may someday help treat a variety of diseases Gene therapy Is the alteration of an afflicted individual’s genes Cloned gene (normal allele) 1 Insert normal gene into virus Viral nucleic acid Retrovirus 2 Infect bone marrow cell with virus 3 Viral DNA inserts into chromosome Bone marrow cell from patient Bone marrow Figure 12.13 4 Inject cells into patient

Gene therapy May one day be used to treat both genetic diseases and nongenetic disorders Unfortunately, progress is slow

GENOMICS CONNECTION 12.15 The Human Genome Project is an ambitious application of DNA technology The Human Genome Project, begun in 1990 and now largely completed, involved Genetic and physical mapping of chromosomes, followed by DNA sequencing Figure 12.15

The data are providing insight into Development, evolution, and many diseases

12.16 Most of the human genome does not consist of genes 12.16 Most of the human genome does not consist of genes The haploid human genome contains about 25,000 genes And a huge amount of noncoding DNA

Much of the noncoding DNA consists of repetitive nucleotide sequences And transposons that can move about within the genome

Differentiation-a cell becomes specialized in structure and function.

Cloning A clone is an individual created by asexual reproduction and thus is genetically identical to a single parent.

Nuclear Transplantation Nuclear Transplantation-the introduction of a nucleus from a body cell into an egg cell to generate an organism identical to the nucleus donor

Nucleus from donor cell Implant blastocyst in surrogate mother Clone of donor is born (reproductive cloning) Remove nucleus from egg cell Add somatic cell from adult donor Grow in culture to produce an early embryo (blastocyst) Remove embryonic Stem cells from blastocyst and grow in culture Induce stem cells to form specialized cells (therapeutic cloning) Figure 11.10

Reproductive Cloning Reproductive cloning-the type of cloning which results in birth of a new individual. Reproductive cloning of nonhuman mammals is useful in research, agriculture, and medicine.

Therapeutic Cloning Therapeutic cloning-when the major aim is to produce embryonic stem cells for therapeutic treatments. Embryonic stem cells-give rise to the different kinds of specialized cells of the body. Embryonic stem cells can perpetuate themselves in culture and give rise to differentiated cells.

12.17 The science of genomics compares whole genomes CONNECTION 12.17 The science of genomics compares whole genomes The sequencing of many prokaryotic and eukaryotic genomes Has produced data for genomics, the study of whole genomes

Besides being interesting themselves Besides being interesting themselves Nonhuman genomes can be compared with the human genome Table 12.17

Proteomics Is the study of the full sets of proteins produced by organisms

GENETICALLY MODIFIED ORGANISMS CONNECTION 12.18 Genetically modified organisms are transforming agriculture

gene within plant chromosome Recombinant DNA technology Can be used to produce new genetic varieties of plants and animals, genetically modified (GM) organisms Agrobacterium tumefaciens DNA containing gene for desired trait Plant cell 1 2 3 Ti plasmid Recombinant Ti plasmid Insertion of gene into plasmid using restriction enzyme and DNA ligase Introduction into plant cells in culture Regeneration of plant T DNA carrying new gene within plant chromosome T DNA Plant with new trait Restriction site Figure 12.18A

Transgenic organisms Are those that have had genes from other organisms inserted into their genomes Figure 12.18B

A number of important crops and plants Are genetically modified A number of important crops and plants Are genetically modified

Genetically Modified Organism Genetically modified organisms-an organism that has acquired one or more genes by artificial means rather than by traditional breeding methods.

Agricultural Applications To feed the planet’s hungry population, biologists have made crop plants that are more tolerant to environmental conditions. The plants are protected from serious damage and yield more food.

12.19 Could GM organisms harm human health or the environment? CONNECTION 12.19 Could GM organisms harm human health or the environment? Development of GM organisms Requires significant safety measures Figure 12.19A

Genetic engineering involves risks Genetic engineering involves risks Such as ecological damage from GM crops Figure 12.19B

CONNECTION 12.20 Genomics researcher Eric Lander discusses the Human Genome Project Genomics pioneer Eric Lander Points out that much remains to be learned from the Human Genome Project Figure 12.20

12.17 The science of genomics compares whole genomes 12.17 The science of genomics compares whole genomes The sequencing of many prokaryotic and eukaryotic genomes Has produced data for genomics, the study of whole genomes