Quantitative traits are conditioned by several genetic determinants. Since such genes influence many important complex traits in various organisms, the identification of quantitative trait loci (QTLs) is of major interest, but still encounters serious difficulties. We detected four linked genes within one QTL, which participate in controlling sporulation efficiency in Saccharomyces cerevisiae. ...

R/qtl is an R package for mapping quantitative trait loci (genetic loci that contribute to variation in quantitative traits) in experimental crosses. Its development began in 2000. There have been 38 software releases since 2001. The latest release contains 35k lines of R code and 24k lines of C code, plus 15k lines of code for the documentation. Challenges in the development and maintenance of...

Airway hyperresponsiveness (AHR) is a key physiological component of asthma, and the genetic basis of this complex trait has remained elusive. We created recombinant congenic mice with increased naive AHR by serially backcrossing A/J mice (which have elevated naive AHR) with C57BL/6J mice and selecting for mice with an elevated naive AHR phenotype. The seventh backcross-generation hyperresponsi...

New alleles are constantly accumulated during intentional crop selection. The molecular understanding of these alleles has stimulated new genomic approaches to mapping quantitative trait loci (QTL) and haplotype multiplicity of the genes concerned. A limited number of quantitative trait nucleotides responsible for QTL variation have been described, but an acceleration in their rate of discovery...

Daylength controls flowering in many plant species. Early in the twentieth century, Garner and Allard (1920) first described the phenomenon of plants that flower only when daylength is longer or shorter than a particular threshold, named long-day and shortday plants, respectively. Rice is a shortday plant; flowering (termed “heading” in rice and other cereals) is promoted by short daylength. Ho...

Daylength controls flowering in many plant species. Early in the twentieth century, Garner and Allard (1920) first described the phenomenon of plants that flower only when daylength is longer or shorter than a particular threshold, named long-day and shortday plants, respectively. Rice is a shortday plant; flowering (termed “heading” in rice and other cereals) is promoted by short daylength. Ho...

Telomere length is a quantitative trait important for many cellular functions. Failure to regulate telomere length contributes to genomic instability, cellular senescence, cancer, and apoptosis in humans, but the functional significance of telomere regulation in plants is much less well understood. To gain a better understanding of telomere biology in plants, we used quantitative trait locus (Q...

The confirmation of the segregation of experimentally discovered quantitative trait loci (QTL) in a variety of commercial populations is required before their commercial significance can be fully realized. The use of complex pedigrees in the design of such confirmation experiments has the potential to increase the probability of the QTL segregating within the pedigree while maintaining the powe...

Genetic influences on anxiety disorders are well documented; however, the specific genes underlying these disorders remain largely unknown. To identify quantitative trait loci (QTL) for conditioned fear and open field behavior, we used an F2 intercross (n = 490) and a 34th-generation advanced intercross line (AIL) (n = 687) from the LG/J and SM/J inbred mouse strains. The F2 provided strong sup...

While the machinery of quantitative genetics can blissfully function in complete ignorance of any of the underlying genetic details, we are certainly interested (at least one some level) on the genetic basis of trait variation. At the most practical level, if a gene of major effect is segregating in our population of interest, we would certainly like to not only to be aware of this, but also to...