Epistasis Blog

From the Artificial Intelligence Innovation Lab at Cedars-Sinai Medical Center (www.epistasis.org)

Saturday, September 10, 2005

Simultaneous mapping of epistatic QTL in DU6i x DBA/2 mice

An interesting new paper by Carlborg et al. in Mammalian Genome describes epistatic effects on growth and body composition traits in mouse crosses. Note the interesting patterns of interactions that are described.

Carlborg O, Brockmann GA, Haley CS. Simultaneous mapping of epistatic QTL in DU6i x DBA/2 mice. Mamm Genome. 2005 Jul;16(7):481-94. [PubMed]


We have mapped epistatic quantitative trait loci (QTL) in an F(2) cross between DU6i x DBA/2 mice. By including these epistatic QTL and their interaction parameters in the genetic model, we were able to increase the genetic variance explained substantially (8.8%-128.3%) for several growth and body composition traits. We used an analysis method based on a simultaneous search for epistatic QTL pairs without assuming that the QTL had any effect individually. We were able to detect several QTL that could not be detected in a search for marginal QTL effects because the epistasis cancelled out the individual effects of the QTL. In total, 23 genomic regions were found to contain QTL affecting one or several of the traits and eight of these QTL did not have significant individual effects. We identified 44 QTL pairs with significant effects on the traits, and, for 28 of the pairs, an epistatic QTL model fit the data significantly better than a model without interactions. The epistatic pairs were classified by the significance of the epistatic parameters in the genetic model, and visual inspection of the two-locus genotype means identified six types of related genotype-phenotype patterns among the pairs. Five of these patterns resembled previously published patterns of QTL interactions.

A recent review paper on epistasis by Carlborg and Haley:

Carlborg O, Haley CS. Epistasis: too often neglected in complex trait studies? Nat Rev Genet. 2004 Aug;5(8):618-25. [PubMed]


At 1:55 PM, Blogger Unknown said...

Great post, I enjoyed reading it.

Adding you to favorites, Ill have to come back and read it again later.


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