Genetic Maping Flashcards
What is the most common Caucasian lethal gene disorder
Cystic fibrosis (AR) 70% of patients. Have a mutation of 3 bp causing the loss of one AA from the protein
What is the most common pathogen
Pseudomonas aeruginosa
Positional Cloning
Cloning a gene purely on the basis of its map position
What is gene mapping dependent on
The tendency of two genes to assort together during meiosis
Test for linkage of 2 known loci
Genome scan linkage analysis
A large set of genetic markers are spread out every .5cM and the gene of interest is tested for linkage to each marker
Test for linkage of 2 known loci Candidate gene approach
If a gene is suspected to lie in a particular region you can directly test for linkage to markers in this region
LOD score method
Maximum likelihood allows you to determine if two genes are linked and what the genetic distance is
LOD Score
Log(P of observing genotype in progeny bc of linkage)/(P of observing genotype bc genes are unlinked)
How to interpret LOD scores
LOD>/=3 then the genes are linked
LOD=-2, the genes are unlinked
What is imperative for linkage analysis
Heterozygosity at both loci
Cytogenic map
Places genes into specific cytogenetic bands on a Karotype
Linkage/genetic map
Orders genes and markers by recombination distance cM
Physical map
Orders genes and markers along the DNA strand in the chromosome by kb distances
DNA sequence
Represents the array of all the genes and markers it encodes
Polymorphic
A genetic locus in a population at which the most common allele has a frequency less than .95
