Post on 04-Jan-2016
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Chapter 20DNA 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 20DNA 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 20DNA 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 20DNA 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 20DNA 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 20DNA Technology and Genomics
DNA FingerprintingHuman 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 20DNA Technology and Genomics
DNA Fingerprinting
Chapter 20DNA 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 FingerprintingRestriction enzymes cut DNA at specific places.
Chapter 20DNA 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 FingerprintingRestriction enzymes cut DNA at specific places.
Chapter 20DNA 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 FingerprintingRestriction enzymes cut DNA at specific places.
Chapter 20DNA 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 FingerprintingRestriction enzymes cut DNA at specific places.
Chapter 20DNA Technology and Genomics
Bill’s chromosome:
Bob’s chromosome:
DNA FingerprintingLonger fragments travel more slowly through the gel.
Chapter 20DNA Technology and Genomics
Bill’s chromosome:
Bob’s chromosome:
DNA Fingerprinting
Chapter 20DNA Technology and Genomics
Bill’s chromosome:
Bob’s chromosome:
DNA Fingerprinting
Chapter 20DNA Technology and Genomics
Bill’s chromosome:
Bob’s chromosome:
Bill’s chromosome:
Bob’s chromosome:
DNA Fingerprinting
Chapter 20DNA Technology and Genomics
Chapter 20DNA 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 20DNA Technology and Genomics
The southern blot
Chapter 20DNA Technology and Genomics
The southern blot
Chapter 20DNA 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 20DNA 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 20DNA Technology and Genomics
Uses of DNA Technology:
Testing for genetic diseases
Large scale production of drugs
Gene therapy
Forensics
Genetic engineering
Chapter 20DNA Technology and Genomics