To compile a complete linkage map from this crossover data, we need to first determine the order of the linked genes on the chromosome. For this, we will use the percentage of crossovers between different gene pairs. The greater the percentage of crossovers, the further apart the genes are on the chromosome.
Here are the steps to create a linkage map from the given data:
1. Begin with the pairs that have the highest percentage of crossovers:
- In the first set of data, B and C have a 50% crossover rate, so we can assume that they are the furthest apart from each other on the chromosome.
- In the second set of data, B and E have a 50% crossover rate. Since B is already linked to C, we know that E must be further down the chromosome than C and D.
2. Identify pairs that have an intermediate percentage of crossovers:
- In the first set of data, A and B have a 50% crossover rate, but we can't place them yet since we don't know if A is closer to B or to C.
- A and D have a 38% crossover rate, which is lower than the rate for A and C (15%), so we can place D closer to A than C.
- A and E have the lowest crossover rate (8%), so we can assume that A and E are closest to each other on the chromosome.
3. Place the remaining gene pair:
- In the second set of data, C and D have a 50% crossover rate, so we can place them next to each other.
Thus, the order of the linked genes on the chromosome is: A - E - D - C - B
We can also calculate the crossover distances between adjacent genes on the chromosome by subtracting their crossover percentages from 50:
- The distance between A and E is 42 (50 - 8)
- The distance between E and D is 12 (50 - 38)
- The distance between D and C is 0 (50 - 50)
- The distance between C and B is 0 (50 - 50)
Therefore, the complete linkage map for the given crossover data is:
```
A-----42-----E-----12-----D-----0-----C-----0-----B
```