TBL 3 Flashcards
A process of identifying a gene by its product
Functional cloning
A process to identify a gene by its location
Positional cloning (uses linkage of markers to disease alleles)
When does crossing over happen?
Prophase I
What is the tendency of loci to be transmitted together as a unit through meiosis (counter to Mendels law)
Linkage
In linkage analysis, distance is estimated by measuring:
Number of recombinations between marker and gene
What is the theoretical maximum recombination frequency?
50%
If gamates possess the same markers as the parent we consider them:
Parental, non-recombinant
If the recombination frequency is 5-50%, the genes/markers must be:
Unlinked
If the recombination rate is less than %5, the genes must be:
Linked
The closer together the loci, the ____ likely a recombination will occur between them
Less
Theta is equal to:
Number of recombinants/ total progeny
0.01 theta is equal to:
1 centiMorgan (cM) = 1% recombination
1cM is roughly equal to how many base pairs?
1.1 million bp’s
Why do females have higher recombination rates?
Long ass gamatogenesis
Why are recombination hot spots important?
Genes will look like they are farther apart than they are
How many informative meiosis samples are needed for dominant gene mapping? Recessive?
10, 20
What is the mode of inheritance for Dyschromatosis Symmetrica Hereditaria (DSH)
AD
How do we compare the probability of obtaining our loci linkage data (theta) vs the probability that they are not linked (theta > 0)
Lod score
If the Lod score (Z) is >0, the evidence does/does not support linkage
Does
If Z < 0, there is evidence ____ linkage
Against
If Z < -2, there is statistically reliable evidence _____ linkage
Against
If Z > 3 there is statistically reliable evidence _____ linkage
Supporting
What is a haplotype?
Collection of alleles on a chromosome
What are the three possible mechanisms by which a mutation will cause an AD disease?
Haploinsufficiency (-> loss of fx)
Gain of function
Dominant negative
What process allows sequencing of disease genes when linkage isn’t feasible?
Econ sequencing
