Genetic Linkage

Genotype Observed Type of Gamete

v cv⁺ct⁺
580
Parental

v⁺cv ct
592
Parental

v cv ct⁺
45
Single-crossover between genes ct and cv

v⁺cv⁺ct
40
Single-crossover between genes ct and cv

v cv ct
89
Single-crossover between genes v and ct

v⁺cv⁺ ct⁺
94
Single-crossover between genes v and ct

v cv⁺ct
3
Double-crossover

v⁺cv ct⁺
5
Double-crossover

Total
1448

Genotype	Observed	Type of Gamete
v cv⁺ct⁺	580	Parental
v⁺cv ct	592	Parental
v cv ct⁺	45	Single-crossover between genes ct and cv
v⁺cv⁺ct	40	Single-crossover between genes ct and cv
v cv ct	89	Single-crossover between genes v and ct
v⁺cv⁺ ct⁺	94	Single-crossover between genes v and ct
v cv⁺ct	3	Double-crossover
v⁺cv ct⁺	5	Double-crossover
Total	1448

Determine the parental genotypes

The most abundant genotypes are v cv⁺ct⁺ and v⁺cv ct.

Determine the gene order

Allele ct is paired with v and cv⁺. This is a different pairing than the parental genotype. Therefore gene ct is in the middle.

Determine the linkage distance

v-ct = 100*((89+94+3+5)/1448) = 13.2 cM
ct-cv = 100*((45+40+3+5)/1448 = 6.4 cM