Gene Mapping Flashcards
When do cross-overs happen?
Occur in almost all meioses
When are cross-overs detectable?
If one parent is heterozygous for two or more genes
How are cross-overs quantified?
With a test cross
True or false: A chromosome can only be 50 mu long
False
What is unique about male Drosophila?
Crossovers do not occur
When do RF’s max out?
At 50% no matter how far apart two genes are
What is a genetic marker?
A mutation at a known location on a chromosome
What if RF is more than 50%
Who knows?
Do SNPs cause missense or frameshift mutations?
SNPs don’t cause either of those
SNPs cause bp substitutions between genes
What are SNPs used for?
As genetic markers
What was the original method of gene mapping?
RFLP mapping
We don’t use it anymore because it was slow, expensive, radioactive, and fussy
What is the current method of gene mapping?
GWAS = genome-wide association study
Isolate DNA from many people and analyze it with a DNA microarray reader
How do we graph GWAS results?
The probability that the mutation is less than 10 mu from each SNP
What does a single peak indicate on a manhattan plot?
One gene is involved in the mutation
What do multiple peaks indicate on a manhattan plot?
Multiple genes are involved in a mutation
