Genetic Mapping in Eukaryotes(Chap 14)

Question 1

Genetic Mapping

Answer 1

• researchers: info on distances b/n genes on chromo + testcross allows link location to be found –> genetic recomb
• uses: genetic recombination exp

Question 2

Early Studies of Genetic Linkage

Answer 2

• Morgan (flies): white eyes/w and minature/m where both on X chromo–> found P#> recomb #… genes on same chromosome

Question 3

Physical proof of Gen Recombin

Answer 3

(1930’s)

• Stern (Drosophila): perform crosses b/n strains that are defined genetic and cytological markers
• Creighton + MMcClintoch (Corn)

Question 4

Contructing Genetic Map

Answer 4

• use linked genes
• independent assortment deviations–> sign= P>rec
• testcross used
• ie: 99%:1% closer and less Crossing over and 50% each = random assort.

Question 5

Cis vs Trans arrgangements

Answer 5

(heterzygous at 2 loci)

• cis/coupling : both mutants on one chromo and wt on the other
• trans/repulsion: each chromo has one of each

-therefor a 1 crossing over b/n trans arrangement results in CIS

Question 6

Crossing over

Answer 6

• crossover frequency: increases with distance b/n genes

- 1%= 1mu = 1 cM

Question 7

Generating a genetic map

Answer 7

• %Recombinant.Frequency= (#observed recom/# observe tota) *100
• -> only an estimation , hotspots exists and double crossover overs b/n 2 loci restore P , previous c.o creates interferences

Question 8

Interference and Coincidence

Answer 8

I=1 –> total interf

-Coefficient of Coin(C)= extent of interference(fre of OBS DCO/fre of EXP DCO) : I=1-C