tailieunhanh - Báo cáo sinh học: " Precision of methods for calculating identity-by-descent matrices using multiple mar"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học thế giới đề tài: Precision of methods for calculating identity-by-descent matrices using multiple mar | 557 Genet. Sel. Evol. 34 2002 557-579 INRA EDP Sciences 2002 DOI gse 2002023 Original article Precision of methods for calculating identity-by-descent matrices using multiple markers Anders Christian S0RENSENa b c Ricardo PoNG-WoNGa Jack J. WiNDiGd John A. WooLLiAMSa a Roslin Institute Edinburgh Roslin Midlothian EH25 9PS UK b Department of Animal Breeding and Genetics Danish Institute of Agricultural Science . Box 50 8830 Tjele Denmark c Department of Animal Science and Animal Health Royal Veterinary and Agricultural University Grpnnegardsvej 2 1870 Frederiksberg C Denmark d Institute for Animal Science ID-Lelystad . Box 65 8200 AB Lelystad The Netherlands Received 13 November 2001 accepted 22 April 2002 Abstract - A rapid deterministic method DET based on a recursive algorithm and a stochastic method based on Markov Chain Monte Carlo MCMC for calculating identity-by-descent IBD matrices conditional on multiple markers were compared using stochastic simulation. Precision was measured by the mean squared error MSE of the relationship coefficients in predicting the true IBD relationships relative to MSE obtained from using pedigree only. Comparisons were made when varying marker density allele numbers allele frequencies and the size of full-sib families. The precision of DET was 75-99 relative to MCMC but was not simply related to the informativeness of individual loci. For situations mimicking microsatellite markers or dense SNP the precision of DET was 95 relative to MCMC. Relative precision declined for the SNP but not microsatellites as marker density decreased. Full-sib family size did not affect the precision. The methods were tested in interval mapping and marker assisted selection and the performance was very largely determined by the MSE. A multi-locus information index considering the type number and position of markers was developed to assess precision. It showed a marked empirical relationship with the observed precision for DET and MCMC .