04BIS1012012RecombinLect4b

L rodriguez 2012 drosophilia trihybrid cross with

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 00=15.3 1980 23.2 *without multiplying the 4 dc by 2 would give a cv-v distance of 22.97 March 19, 2012 BIS101001, Spring 2012--Genes and Gene Expression, R.L. Rodriguez 2012 39 Interference If crossing over occurs independently in the two regions (i.e., if the occurrence of one exchange does not alter the probability of the second exchange), the probability of simultaneous exchanges in both regions should be the product of the single crossover probabilities as follows: Pcv-ct (0.079) X Pct-v (0.153) = Pcv-v (0.012) or 1.2% (1.2% of 1980 total progeny is 24 dc progeny) Actual results indicate 4 double crossovers (Pcv-v of 0.002) not 24. The reduced number of double crossover progeny, relative to the expected number, is called interference and it can be calculated as follows. BIS101001, Spring 2012--Genes and Gene Expression, R.L. Rodriguez 2012 40 March 19, 2012 Calculating Interference Interference = 1- Coefficient of Coincidence, where Coefficient of Coincidence = % observed double cro...
View Full Document

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.

Ask a homework question - tutors are online