chapter 19 - chromatin dna packagingdna packaging histone proteinhistone protein...
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Chapter 19 - ChromatinChapter 19 - Chromatin
•DNA PackagingDNA Packaging•histone protein histone protein
•NucleosomeNucleosome •””beads on a string” basic beads on a string” basic unit of DNA packingunit of DNA packing
•HeterochromatinHeterochromatin•highly condensed highly condensed interphase DNA interphase DNA
•(can not be transcribed)(can not be transcribed)•EuchromatinEuchromatin
•less compacted interphase less compacted interphase DNA DNA (can be transcribed)(can be transcribed)
Recombinant DNARecombinant DNA Def:Def: DNA in which DNA in which
genes from 2 different genes from 2 different sources are linkedsources are linked
Genetic engineering:Genetic engineering: direct manipulation of direct manipulation of genes for practical genes for practical purposespurposes
Biotechnology:Biotechnology: manipulation of DNA manipulation of DNA or organisms to or organisms to perform practical perform practical tasks or provide tasks or provide useful productsuseful products
DNA CloningDNA Cloning Restriction enzymes (endonucleasesRestriction enzymes (endonucleases):):
– in nature, these enzymes protect bacteria from in nature, these enzymes protect bacteria from intruding DNA; they cut up the DNA intruding DNA; they cut up the DNA (DNA (DNA scissors)scissors) very specificvery specific
Restriction siteRestriction site::– recognition sequence for a particular recognition sequence for a particular
restriction enzymerestriction enzyme Restriction fragmentsRestriction fragments::
– segments of DNA cut by restriction enzymes in segments of DNA cut by restriction enzymes in a reproducable waya reproducable way
Sticky endSticky end::– short extensions of restriction fragmentsshort extensions of restriction fragments
DNA ligaseDNA ligase: : – enzyme that can join the sticky ends of DNA enzyme that can join the sticky ends of DNA
fragmentsfragments Cloning vectorCloning vector: :
– DNA molecule that can carry foreign DNA into DNA molecule that can carry foreign DNA into a cell and replicate there (usually bacterial a cell and replicate there (usually bacterial plasmids)plasmids)
Steps for eukaryotic gene cloningSteps for eukaryotic gene cloning
Isolation of (bacterial plasmid / Isolation of (bacterial plasmid / cloning vectorcloning vector) & gene-source ) & gene-source DNA (gene of interest)DNA (gene of interest)
Insertion of DNA into the cloning Insertion of DNA into the cloning vector using the same vector using the same restriction enzyme; bind the restriction enzyme; bind the fragmented DNA with DNA fragmented DNA with DNA ligaseligase
Introduction of cloning vector Introduction of cloning vector into cells into cells (transformation by (transformation by bacterial cells)bacterial cells)
Cloning of cells Cloning of cells (and foreign (and foreign genes)genes)
Identification of cell clonesIdentification of cell clones
DNA Analysis & GenomicsDNA Analysis & Genomics
PCR PCR (polymerase chain (polymerase chain reaction)reaction)
Gel Gel electrophoresiselectrophoresis Restriction fragment Restriction fragment
analysis (RFLPs)analysis (RFLPs) Southern blottingSouthern blotting DNA sequencingDNA sequencing Human genomeHuman genome projectproject
Polymerase chain reaction (PCR)Polymerase chain reaction (PCR)
Amplification of any Amplification of any piece of DNA without piece of DNA without cells (in vitro)cells (in vitro)
Materials: heat, DNA Materials: heat, DNA polymerase, polymerase, nucleotides, single-nucleotides, single-stranded DNA primersstranded DNA primers
Applications: fossils, Applications: fossils, forensics, prenatal forensics, prenatal diagnosis, etc.diagnosis, etc.
DNA AnalysisDNA Analysis
Gel electrophoresisGel electrophoresis: separates nucleic acids or proteins on the : separates nucleic acids or proteins on the basis of size or electrical charge creating DNA bands of the basis of size or electrical charge creating DNA bands of the same lengthsame length
Restriction fragment analysisRestriction fragment analysis
Restriction fragment length polymorphisms (RFLPs)Restriction fragment length polymorphisms (RFLPs) Southern blottingSouthern blotting: process that reveals sequences and : process that reveals sequences and
the RFLPs in a DNA sequencethe RFLPs in a DNA sequence DNA FingerprintingDNA Fingerprinting
DNA SequencingDNA Sequencing
Determination of Determination of nucleotide sequences nucleotide sequences (Sanger method, (Sanger method, sequencing machine)sequencing machine)
Genomics: the study of Genomics: the study of genomes based ongenomes based onDNA sequencesDNA sequences
Human Genome Human Genome ProjectProject
Practical DNA Technology UsesPractical DNA Technology Uses
Diagnosis of diseaseDiagnosis of disease Human gene therapyHuman gene therapy Pharmaceutical products Pharmaceutical products
(vaccines)(vaccines) ForensicsForensics Animal husbandry Animal husbandry
(transgenic organisms)(transgenic organisms) Genetic engineering in plantsGenetic engineering in plants Ethical concerns?Ethical concerns?
O.J. Simpson murder case - 1995 Odds of blood in Ford Bronco not being R. Goldman’s:
6.5 billion to 1 Odds of blood on socks in bedroom not being N. Brown-Simpson’s:
8.5 billion to 1 Odds of blood on glove not being from R. Goldman, N. Brown-Simpson, and O.J. Simpson:
21.5 billion to 1 Number of people on planet earth:
7+ billion Odds of being struck by lightning in the U.S.:
2.8 million to 1 Odds of winning the Ohio lottery:
76 million to 1 Odds of getting killed driving to the gas station to buy a lottery ticket
4.5 million to 1 Odds of seeing 3 albino deer at the same time:
85 million to 1 Odds of having quintuplets:
85 million to 1 Odds of being struck by a meteorite:
10 trillion to 1