In the case of three genes it is just a simple extension of two genes.

Let f=0.2 which is the frequency of crossing over between a and b and

let g=0.1 which is the frequency of crossing over between b and c.

Description genotype P

f=.2
g=.1

 N=1000

Parental type one

 a+ b+ c+ (1-f-g)/2 0.35 350
Parental type two a b c (1-f-g)/2 0.35 350

Region I Recombinant

a+ b c

 f(1-g)/2 0.09 90
Region I Recombinant a b+ c+ f(1-g)/2 0.09 90
Region II Recombinant abc+ g(1-f)/2 0.04 40
Region II Recombinant a+b+c g(1-f)/2 0.04 40
Double C/O a+bc+ f*g/2 0.01 10
Double C/O ab+c f*g/2 0.01 10

 

Text iGenetics by Peter J. Russell

This web site is provided for instruction in Botany and Zoology 342

by Kenneth G. Wilson,
Professor of Botany
Miami University
wilsonkg@muohio.edu