Unformatted text preview: ce: The distance between gene loci on a chromosome can be measured in terms of the recombination frequency (RF), produced by crossing over between two loci during meiosis. Roughly, 1% recombination equals 1 map unit (m.u.) for short distances (e.g., 1 to 15% RF). Gene order and the 3 factor cross (trihybrid cross) : Interlocus map distances based on recombination measurements are roughly additive and can be used to determine gene order. Interference: One crossover can influence the occurrence of a second crossover in an adjacent region. Interference distorts map distances. Mapping function: For recombination frequencies (RF) larger than 15%, the 1 to 1 relationship between RF and m.u. breaks down. For example, an RF of 27.5% actually equals 40 m.u. March 19, 2012 BIS101001, Spring 2012--Genes and Gene Expression, R.L. Rodriguez 2012 3 Linkage Genes are linked to other genes. What does this mean for Mendelian inheritance and how can linkage be used to understand gene and chromosome structure? March 19, 2012 BIS10...
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- Genetic linkage, Chromosomal crossover, R.L. Rodriguez ©2012