Book : Molecular Biology
posted by
Posted by: CHELSEA
posted by
Writer CHELSEA

Double Crossovers

image about


Overview

If all three markers are in the same linkage group, that is, on the same chromosome, then we can observe an ABC/abc undergoing two recombination events, one between A and B, and another between B and C, to give AbC/aBc. This is what is going on in cells 7 and 8 of the earlier example. If we had been looking only at dihybrid test cross data, then we would not be able to detect these double recombinants. One notices that double recombinants are not very common, so the effect on the estimates of the percent recombination is not large. The corollary of this is that most chromosomes will experience only zero or one recombinants. The estimated double recombination rate does add to our estimate of the distance between the more distant loci (A and C in the example). Trow's formula states that: cAC = cAB+cBC-2cABcBC



related articles

DNA Replication

DNA Replication

  • Basics
  • posted Date:2017 Sep, 16

DNA Replication is Semi-Conservative...

read more
Mitochondrial inheritance

Mitochondrial inherita...

  • Basics
  • posted Date:2017 Sep, 16

OverviewMitochondria are...

read more
The Structure of tRNA

The Structure of tRNA

  • Basics
  • posted Date:2017 Sep, 16

OverviewTransfer RNA molecules vary in length between 60 and 95...

read more

Subscribe With Us For Daily Reading Lesson Materials