We have used the results of an experiment mapping quantitative trait loci (QTL) affecting milk yield and composition to estimate the total number of QTL affecting these traits. We did this by estimating the number of segregating QTL within a half-sib daughter design using logic similar to that used to estimate the "false discovery rate" (FDR). In a half-sib daughter design with six sire familie...

Knowing the large difference in daily feed intake (DFI) between Large White (LW) and Piétrain (PI) growing pigs, a backcross (BC) population has been set up to map QTL that could be used in marker assisted selection strategies. LW × PI boars were mated with sows from two LW lines to produce 16 sire families. A total of 717 BC progeny were fed ad libitum from 30 to 108 kg BW using single-place e...

From simulation studies it is known that the allocation of experimental resources has a crucial effect on power of QTL detection as well as on accuracy and precision of QTL estimates. In this study, we used a very large experimental data set composed of 976 F(5) maize testcross progenies evaluated in 19 environments and cross-validation to assess the effect of sample size (N), number of test en...

Quantitative trait locus (QTL) mapping is usually performed using markers that follow a Mendelian segregation ratio. We developed a new method of QTL mapping that can use markers with segregation distortion (non-Mendelian markers). An EM (expectation-maximization) algorithm is used to estimate QTL and SDL (segregation distortion loci) parameters. The joint analysis of QTL and SDL is particularl...

Abstract Phenotypes of sessile organisms, such as plants, rely not only on their own genotypes but also those neighboring individuals. Previously, we incorporated neighbor effects into a single-marker regression using the Ising model ferromagnetism. However, little is known regarding how should be in quantitative trait locus (QTL) mapping. In this study, propose new method for interval QTL mapp...

An F2 cross between Duroc and Large White pigs was carried out in order to detect quantitative trait loci (QTL) for 11 meat quality traits (L*, a* and b* Minolta coordinates and water-holding capacity (WHC) of two ham muscles, ultimate pH of two ham and one loin muscles), 13 production traits (birth weight, average daily gain during post-weaning and fattening periods, carcass fat depths at thre...

Carlborg, Ö. 2002. New Methods for Mapping Quantitative Trait Loci. Doctoral dissertation. ISSN 1401-6257, ISBN 91-576-6362-9 This thesis presents and discusses the use of various genetic models, high performance computing, global optimization algorithms and statistical methods for mapping Quantitative Trait Loci (QTL). The aim of the work has been to develop statistically powerful and computat...

A QTL study was performed in large half-sib families to characterize the genetic background of variation in pork quality traits as well as to examine the possibilities of including QTL in a marker-assisted selection scheme. The quality traits included ultimate pH in LM and the semimembranosus, drip loss, and the Minolta color measurements L*, a*, and b* representing meat lightness, redness, and...

Molecular mapping of Fusarium head blight (FHB) resistance quantitative trait loci (QTL) and marker-assisted selection of these QTL will aid in the development of resistant cultivars. Most reported FHB resistance QTL are from 'Sumai 3' and its derivatives. 'Wangshuibai' is a FHB-resistant landrace that originated from China and is not known to be related to 'Sumai 3'. A mapping population of 13...