Sollars - Gene Mapping

Question 1

Gene Mapping

Answer 1

Assignment of genes to specific chromosome locations

Question 2

Genome Scan Linkage Anlysis

Answer 2

Aren’t sure, bumping against strandard–casting a wide net

Question 3

Candidate Gene Approach

Answer 3

Gene suspected to lie in a particular region. Used to rule out or rule in suspected disease gene that has already been mapped.

Have an idea, specific testing–soda straw

Question 4

Genetic Map: Cytogenic Map

Answer 4

Places genes into specific cytogenetic bands of karyotype

Question 5

Genetic Maps: Linkage or Genetic Map

Answer 5

Orders genes and genetic markers by recombinatyion distance (cM)

Question 6

Genetic Maps: Physical Map

Answer 6

Orders genes and geneteic markers along the DNA strand of a chromosome; d measure in kb

Question 7

Genetic Maps: DNA Sequence

Answer 7

Array of all genes and markers it encodes

Sort of a map..

Question 8

What are some important usage of genetic mapping?

Answer 8

Understand function of human genome

Segregation of genetic disease

Gene therapy strategy development

Clinically useful linkage information

Question 9

What is required for loci to be informative in genetic mapping?

Answer 9

Need heterozygosity at the marker locus and disease gene locus

Question 10

If Phase is known, what is result of statistical power?

Answer 10

Doubled

Need heterozygosity and haplotypes for at least three generations

Question 11

What can throw off calculated genetic distance vs actual physical distances?

Answer 11

Not all regions form chiasmatas with equal efficiences (interference)

Question 12

LOD Score (Z) Method of Determining Linkage

Answer 12

Log of ratio of likelihood that a given pedigree can be obtained given a recombination frequency, theta, compared to the likelihood that the pedigree arose with no linkage.

Allows determination if genes are linked and the distance between them (cM)

Z must be >3 to assume linkage

Does NOT require phase, but knowing it can double the power

Question 13

Restriction Fragment Length Polymorphisms (RFLPs)

Answer 13

Variations occuring within a species in the lngth of DNA fragments generated by specific endonuclease. Creat or abolish recognition sites for these enzymes.

Question 14

What must you know for RFLP analysis?

How is it commonly used (disease-wise)?

Answer 14

Genotype for disease and RFLP locus

Phase

Distance between loci in cM

Determination of PKD1, PKD2

Question 15

Cystic Fibrosis

Answer 15

Autosomal Recessive Pattern

Most common leathal disorder in caucasians; first identified using positional cloning

Question 16

Positional cloning

Answer 16

Cloning a gene on basis of it’s map position, without knowing what gene does or its molecular function