04BIS1012012RecombinLect4b

L rodriguez 2012 19 mapping genes on chromosomes

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Unformatted text preview: mosomes Since the breakage-reunion events (crossovers ) between two loci on non-sister chromatids are independent events, it follows that the probability (p) of a crossover occurring will be related to the distance between the two loci. As shown below, there are more potential crossovers sites between loci B and C than between A and B. Therefore a map based on recombination frequency (RF) should be wider (i.e., more map units -- m.u.) between loci B and C than A and B. A a B b C c An odd number of crossovers is needed to recombine loci March 19, 2012 BIS101001, Spring 2012--Genes and Gene Expression, R.L. Rodriguez 2012 20 Relationship between RF and Gene Distance March 19, 2012 BIS101001, Spring 2012--Genes and Gene Expression, R.L. Rodriguez 2012 21 Double Crossovers involving 3 loci In the example below, a trihybrid cross is performed involving three loci; vestigial (v), cut (ct) and crossveinless (cv). A double crossover occurs between v and cv. Note that only the middle (ct) of the 3 loci switches...
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This note was uploaded on 03/18/2012 for the course BIS 101 taught by Professor Simonchan during the Winter '08 term at UC Davis.

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