Ch 20 Genomics I: analysis of DNA Flashcards
(41 cards)
Genome
total genetic composition of organism or species
Genomics
molecular analysis of an entire genome of a species
Functional Genomics
examining genes to discover how thye interact to produce traits of an organism
Structural Genomics
looking at proteins to see how genes interact to produce traits of an organism
Proteomics
analysis of proteins of an entire genome
Mapping
figuring out relative location of genes or segments of DNA on a chromosome
Three ways to determine the organization of a genome?
Cytogenic Mapping, PHysical mapping, linkage mapping
Cytogenetic Mapping
Determines location of gene along intact chromsome
In what instance is cytogenetic mapping used?
With eukyotes because they have large chromsomes that can be looked at microscopically and individually categorized based on banding pattern of chromsomeos
How accurate is cytogenetic mapping
Not super accurate becase it is only as good as the resolution of the microscope. Limit of approx. 5 mil base pairs. This is like a preliminary step for locating genes before physical mapping is used.
FISH
Flourescence in situ hybridization
-Used to detect location of gene on chromsomes. that is HELD IN PLACE.
How does FISH work?
1) Treat chromsomes of interest with agent that makes them swell and FIX to slide
2) Denature chromsomes
3) Add SINGLE STRANDED dna probes that have biotin
4) Add floresently labeled avidin that bind to biotin
5) View with microscope
* USually have two spots at each location because bound to both chromatids!
Molecular Markers
Small segements of DNA that have unique qualities that can be seen under microscope or recognized by PCR and gel electrophoreses. Serve as guidlines along chromsomes to locate relative position of other genes
Polymorphic Molecular Markers
Used in analysis of pedigrees to find mutant genes causing diseases
How are restriciton enzymes used in physical mapping?
Used to create restriction fragments. Recognize palindromes and break chromsome into many smal pieces depending on spacing of palindromes
How does random mutation effect palindromes?
In can either create or destroy palindromes
EcoRi
Example of a restriction enzyme that recognizes 5-GAATC and digestes the chromosome into small pieces respectivly
RFLP
Restriction fragment length polymorphism. Looking at chromsomes of different individuals in a pop. and seeing different lengths of restriction fragments due to loss or gain of palindromes
Sourthern Blotting uses
used to deterime polymorphism fragments
Microsatellites
Also reffered to as STR’s (Short tandem repeats) are short repetitive sequences interspersed throughout the genome
Most common microsatellite in humans?
CAn (n is anywhere from 5-50 bp)
*found in every 10,000 base pairs
What is sequece Tagged Site and how is it made?
Amplified microsatellite
*amplified using PCR
How are STS sites made in detail?
STS is made using PCR.
1) add PCR primers that specifically target a sequence of a particular chromsome.
2) Many cycles of PCR produce the DNA fragment between the two primers.
3) Use gel electrophoresis that shows the microsatellites
What are the two types of STS instances?
In homozygous individuals two microsatellites will be produced that are identical in length.
In Heterozygous the microsatellites might differ in length