Heterosis, one of the most important biological phenomena, refers to the phenotypic superiority of a hybrid over its genetically diverse parents with respect to many traits such as biomass, growth rate and yield. Despite its successful application in breeding and agronomic production of many crop and animal varieties, the molecular basis of heterosis remains elusive. The classic genetic explana...

Heterosis is important for agriculture; however, little is known about the mechanisms driving hybrid vigor. Ultimately, heterosis depends on the interactions of specific alleles and epialleles provided by the parents, which is why hybrids can exhibit different levels of heterosis, even within the same species. We characterize the development of several intraspecific Arabidopsis (Arabidopsis tha...

To assess the value of DNA fingerprints for the prediction of heterosis in chickens, retrospective analyses of data from three crossbreeding experiments and DNA fingerprints (DEP) of parental strains were conducted using two minisatellite and one middle-repetitive DNA probes. DEP bands were assessed on pooled DNA samples of 10-15 individuals per parental genetic group. The number of DEP bands e...

The genetic basis of heterosis has implications for many problems in genetics and evolution. Heterosis and inbreeding depression affect human genetic diseases, maintenance of genetic variation, evolution of breeding systems, agricultural productivity, and conservation biology. Despite decades of theoretical and empirical studies, the genetic basis of heterosis has remained unclear. I mapped via...

Heterosis is important for agriculture; however, little is known about the mechanisms driving hybrid vigor. Ultimately, heterosis depends on the interactions of specific alleles and epialleles provided by the parents, which is why hybrids can exhibit different levels of heterosis, even within the same species. We characterize the development of several intraspecific Arabidopsis (Arabidopsis tha...

Crossbred steer and heifer progeny from 5-, 6- and 7-yr-old dams produced in a four-breed diallel crossing experiment involving the Brown Swiss, Red Poll, Hereford and Angus maternal grandsires and maternal granddams were evaluated for postweaning growth and carcass traits to estimate breed mean maternal heterosis, maternal heterosis for specific breed cross females, average maternal heterosis ...

LTHOUGH exploitation of heterosis in hybrid maize is so far the most successful A single achievement of applied genetics, understanding of the causes responsible for this phenomenon remains still unsatisfactory. Much of the work on heterosis has been purely empirical and descriptive. Analytical studies have been conspicuously rare, and this in spite of the fact that heterosis is a term which, a...

Sixteen "isogenic" lines of Atlas 46 barley differing in one to four short chromosome segments, and 16 heterozygotes obtained by crossing these lines to male-sterile Atlas, were used to study the effect of level of heterozygosity on performance. In field tests conducted in four environments (two planting dates in two years) significant differences were found among the homozygous isogenic lines ...

Heterosis and breed differences were estimated for milk yield traits, somatic cell score (SCS), and productive life (PL), a measure of longevity. Yield trait data were from 10,442 crossbreds and 140,421 purebreds born since 1990 in 572 herds. Productive life data were from 41,131 crossbred cows and 726,344 purebreds born from 1960 through 1991. The model for test-day yields and SCS included eff...