title: Detecting parent of origin and dominant QTL in a two-generation commercial poultry pedigree using variance component methodology.
abstract: BACKGROUND
  Variance component QTL methodology was used to analyse three candidate regions on chicken chromosomes 1, 4 and 5 for dominant and parent-of-origin QTL effects. Data were available for bodyweight and conformation score measured at 40 days from a two-generation commercial broiler dam line. One hundred dams were nested in 46 sires with phenotypes and genotypes on 2708 offspring. Linear models were constructed to simultaneously estimate fixed, polygenic and QTL effects. Different genetic models were compared using likelihood ratio test statistics derived from the comparison of full with reduced or null models. Empirical thresholds were derived by permutation analysis.
  
  
  RESULTS
  Dominant QTL were found for bodyweight on chicken chromosome 4 and for bodyweight and conformation score on chicken chromosome 5. Suggestive evidence for a maternally expressed QTL for bodyweight and conformation score was found on chromosome 1 in a region corresponding to orthologous imprinted regions in the human and mouse.
  
  
  CONCLUSIONS
  Initial results suggest that variance component analysis can be applied within commercial populations for the direct detection of segregating dominant and parent of origin effects.
authors.affiliation: Roslin Institute and R(D)SVS, University of Edinburgh, Midlothian, UK. Suzanne.Rowe@Roslin.ed.ac.uk
authors.forename: Suzanne J
authors.initials: SJ
authors.lastname: Rowe
authors.forename: Ricardo
authors.initials: R
authors.lastname: Pong-Wong
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Haley
authors.forename: Sara A
authors.initials: SA
authors.lastname: Knott
authors.forename: Dirk-Jan
authors.initials: DJ
authors.lastname: De Koning
mesh_terms: D000818:Animals; D001835:Body Weight; D002645:Chickens / Q000235:genetics*; D002874:Chromosome Mapping; D002875:Chromosomes / Q000235:genetics; D003433:Crosses, Genetic; D005260:Female; D018392:Genomic Imprinting; D006801:Humans; D008297:Male; D051379:Mice; D010375:Pedigree; D040641:Quantitative Trait Loci