title: Multiallelic epistatic model for an out-bred cross and mapping algorithm of interactive quantitative trait loci.
abstract: BACKGROUND
  Genetic mapping has proven to be powerful for studying the genetic architecture of complex traits by characterizing a network of the underlying interacting quantitative trait loci (QTLs). Current statistical models for genetic mapping were mostly founded on the biallelic epistasis of QTLs, incapable of analyzing multiallelic QTLs and their interactions that are widespread in an outcrossing population.
  
  
  RESULTS
  Here we have formulated a general framework to model and define the epistasis between multiallelic QTLs. Based on this framework, we have derived a statistical algorithm for the estimation and test of multiallelic epistasis between different QTLs in a full-sib family of outcrossing species. We used this algorithm to genomewide scan for the distribution of multiallelic epistasis for a rooting ability trait in an outbred cross derived from two heterozygous poplar trees. The results from simulation studies indicate that the positions and effects of multiallelic QTLs can well be estimated with a modest sample and heritability.
  
  
  CONCLUSIONS
  The model and algorithm developed provide a useful tool for better characterizing the genetic control of complex traits in a heterozygous family derived from outcrossing species, such as forest trees, and thus fill a gap that occurs in genetic mapping of this group of important but underrepresented species.
authors: Center for Statistical Genetics, The Pennsylvania State University, Hershey, PA 17033, USA.
authors: Chunfa
authors: C
authors: Tong
authors: Bo
authors: B
authors: Zhang
authors: Zhong
authors: Z
authors: Wang
authors: Meng
authors: M
authors: Xu
authors: Xiaoming
authors: X
authors: Pang
authors: Jingna
authors: J
authors: Si
authors: Minren
authors: M
authors: Huang
authors: Rongling
authors: R
authors: Wu
mesh_terms: D000465:Algorithms; D003433:Crosses, Genetic; D004843:Epistasis, Genetic; D008957:Models, Genetic; D009010:Monte Carlo Method; D032107:Populus / Q000235:genetics; D040641:Quantitative Trait Loci; D012984:Software