Genetics double recombination counted twice in terms of RF

[despues357]

When mapping out re-combinations of a crossed trihybrid you have to account for the proportion of the offspring who do not share parental genotypes.

Of the 8 possible genotypes stemming from this mating, 6 will be recombinant and two will be of parental genotypes.

Your idea is to Map out the distance between each Subject allele that crossed over by counting their recombinant frequency value as map units (centrimorgans).I'm not sure why you would count double recombinants as twice their frequency simply because there were two cross overs. more like, I can't visualize how that could be interpreted as doubling the perceived distance between these two loci...

 

[Ygggdrasil]

To figure out the distance between two genes, you need to figure out the recombination frequency, which is the number of crossover events that happen between the two genes divided by the total number of progeny tested. In the double recombinant, there are two crossover events happening between the V and CV genes. Therefore, you need to take this into account when calculating the recombination frequency.