Recombinant inbred (RI) strains are sets of organisms which have been
derived by inbreeding F2 progeny from a cross of two inbred strains. For
RI strains of mice, which are created by sib-mating, Haldane and Waddington
showed that
r = R/(4-6R)
where r is the estimated probability of recombination between two Mendelian
loci and R is the proportion of RI strains which are recombinant for those
loci. For RI strains of plants, which are created by self-pollination,
Haldane and Waddington showed that
r = R/(2-2R)
Green showed that, for RI strains of mice, the variance of r is given by
v = r(1+2r)(1+6r)^2/4N
where v is the estimated variance, N is the number of strains in the set,
and ^ indicates exponentiation.
By analogy with Green's derivation, I find that the variance of r for selfed
RI strains is given by
v = r(1+2r)^2/2N
I'm sure I am not the first to derive this formula. However, not being a
plant geneticist and not having easy access to most of the plant genetics
literature, I don't know how to find who did derive it. Can anyone help
me with a reference?
Ken Manly
cammanly at ubvms.cc.buffalo.edukmanly at mcbio.med.buffalo.edu