tailieunhanh - Báo cáo khoa hoc:" Abstract - Two methods are presented that use "

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học thế giới đề tài: Abstract - Two methods are presented that use | Genet. Sei. Evol. 31 1999 375-394 Inra Elsevier Paris 375 Original article Marker assisted estimation of breeding values when marker information is missing on many animals Theo . Meuwissena Mike E. Goddardb a Research Institute of Animal Science and Health Box 65 8200 AB Lelystad the Netherlands b Institute of Land and Food Resources University of Melbourne Parkville Victoria 3052 Australia Received 15 December 1998 accepted 4 June 1999 Abstract - Two methods are presented that use information from a large population of commercial animals which have not been genotyped for genetic markers to calculate marker assisted estimates of breeding value MA-EBV for nucleus animals where the commercial animals are descendants of the marker genotyped nucleus animals. The first method reduced the number of mixed model equations per commercial animal to one instead of one plus twice the number of marked quantitative trait loci in conventional MA-EBV equations. Without this reduction the time taken to solve the mixed model equations including markers could be very large especially if the number of commercial animals and the number of markers is large. The solutions of the reduced set of equations were exact and did not require more iterations than the conventional set of equations. A second method was developed for the situation where the records of the commercial animals were not directly available to the nucleus breeding programme but conventional non-MA-EBVs and their accuracies were available for nucleus animals from a large scale . national breeding value evaluation which uses nucleus and commercial information. Using these non-MA-EBV the MA-EBV of the nucleus animals were approximated. In an example the approximated MA-EBV were very close to the exact MA-EBV. Inra Elsevier Paris marker assisted selection breeding value estimation quantitative trait loci DNA markers Resume - Evaluation génétique assistée par marqueurs quand I information sur les marqueurs est rare. On .