Chapter 20 DNA Technology and Genomics

Viruses have restriction enzymes to attack and destroy invading viral DNA. Restriction enzymes cut DNA at specific nucleotide sequences leaving “sticky ends.” DNA ligase can seal these ends, making recombinant DNA. Chapter 20 DNA Technology and Genomics

Restriction fragments can be put into plasmids. Gene cloning occurs when cells containing these plasmids reproduce. Genes of interest are marked with a radioactive DNA probe. Chapter 20 DNA Technology and Genomics

If a gene is inserted next to a promoter, the bacteria becomes an expression vector. Eukaryotic chromosomes allow for bigger segments of DNA. Eukaryotic cells can also process polypeptides into proteins. Chapter 20 DNA Technology and Genomics

Chopping up the whole genome of an organism produces many DNA fragments containing many genes. Often, the researcher will save all of them, either in bacteria or in viruses. These collections of bacterial clones are called genomic libraries. Chapter 20 DNA Technology and Genomics

Polymerase chain reaction (PCR) uses DNA polymerase to clone DNA in vitro. In vitro = in a test tube In vivo = in a living organism Chapter 20 DNA Technology and Genomics

DNA Fingerprinting Human DNA contains lots of noncoding sequences that serve no purpose. This “junk DNA” often repeats over and over. No two people (except identical twins) have exactly the same repeats. Chapter 20 DNA Technology and Genomics

DNA Fingerprinting Chapter 20 DNA Technology and Genomics Bill’s chromosome: gene A xxxxx gene B yyy gene C Bob’s chromosome: gene A xx gene B yyyyy gene C

DNA Fingerprinting Restriction enzymes cut DNA at specific places. Chapter 20 DNA Technology and Genomics Bill’s chromosome: gene A xxxxx gene B yyy gene C Bob’s chromosome: gene A xx gene B yyyyy gene C

DNA Fingerprinting Restriction enzymes cut DNA at specific places. Chapter 20 DNA Technology and Genomics Bill’s chromosome: gene A xxxxx gene B yyy gene C Bob’s chromosome: gene A xx gene B yyyyy gene C

DNA Fingerprinting Restriction enzymes cut DNA at specific places. Chapter 20 DNA Technology and Genomics Bill’s chromosome: gene A xxxxx gene B yyy gene C Bob’s chromosome: gene A xx gene B yyyyy gene C

DNA Fingerprinting Restriction enzymes cut DNA at specific places. Chapter 20 DNA Technology and Genomics Bill’s chromosome: Bob’s chromosome:

DNA Fingerprinting Longer fragments travel more slowly through the gel. Chapter 20 DNA Technology and Genomics Bill’s chromosome: Bob’s chromosome:

DNA Fingerprinting Chapter 20 DNA Technology and Genomics Bill’s chromosome: Bob’s chromosome:

DNA Fingerprinting Chapter 20 DNA Technology and Genomics Bill’s chromosome: Bob’s chromosome:

Bill’s chromosome: Bob’s chromosome: DNA Fingerprinting Chapter 20 DNA Technology and Genomics

The southern blot 1.Do DNA fingerprinting on an entire genome. 2.Blot the DNA from the gel to paper with an alkaline solution. This denatures the DNA. 3.Hybridize with a radioactive probe. Chapter 20 DNA Technology and Genomics

The southern blot Chapter 20 DNA Technology and Genomics

The southern blot Chapter 20 DNA Technology and Genomics

RFLPs (“RIF-lips”), or restriction fragment length polymorphisms, are differences in homologous chromosomes that give different length restriction fragments. Chromosome walking means finding where fragments of DNA overlapped in the genome. Chapter 20 DNA Technology and Genomics

Genomics is the systematic study of entire genomes. Proteomics is the study of all the proteins encoded by a genome. Single nucleotide polymorphisms (SNPs) are useful markers for studying variation. Chapter 20 DNA Technology and Genomics

Uses of DNA Technology: Testing for genetic diseases Large scale production of drugs Gene therapy Forensics Genetic engineering Chapter 20 DNA Technology and Genomics