Unformatted text preview: s done by comparing parental phenotypes to double crossover phenotypes. From the gene order, recombinant progeny produced by recombination between loci can be calculated and these calculations will take into account double crossover progeny. If double crossover progeny are not accounted for, the map distances will not add up properly.
BIS101001, Spring 2012--Genes and Gene Expression, R.L. Rodriguez 2012 27 March 19, 2012 3 Approaches to Constructing Genetic Maps Approach 1. Determining gene order using multiple, two factor crosses involving overlapping loci. Gene order will be revealed by consistent map distances. March 19, 2012 BIS101001, Spring 2012--Genes and Gene Expression, R.L. Rodriguez 2012 28 3 Factor Test Cross without Double Crossovers Approach 2. Perform a 3-factor test cross (F1 x tester) and determine genetic distances first. As above, gene order will be revealed by consistent map distances between the three loci. This approach can be performed without rare double crossover progeny. 3-Factor Crosses without double cr...
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- Genetic linkage, Chromosomal crossover, R.L. Rodriguez ©2012