BIO341 Meiotic mapping of whole genomes (methods for

simultaneously evaluating linkage relationships among

large numbers of loci)

From: Principles of Genetics. 1997. Snustad et al.

From: Principles of Genetics. 1997. Snustad et al.

Linkage analysis of Elliptocytosis and Rh factor

From: Principles of Genetics. 1997. Snustad et al.

Summary

• LOD score analysis of linkage compares two possibilities: two loci are (a) linked at some specified recombination frequency and (b) are unlinked (rec. =50%). LOD = log10(probability of a genotype under a/ probability of the same genotype under b)

• Each progeny individual makes a positive or negative contribution to LOD.

• LOD scores of progeny from different families or crosses can be combined.

• A LOD score total of 3.0 or greater is generally considered strong evidence of linkage.

• Recombination frequency itself can be estimated by calculating LOD for different recombination values. The recombination frequency resulting in the maximum LOD score is treated as the most likely.