Embryo transfers were used to demonstrate that the genotype of the mother providing the uterine developmental environment significantly influences postnatal growth and adult body size of her progeny. Irrespective of their own genotype, mouse embryos transferred into the uterus of an inbred strain with large body size (C3H) had greater body weights, longer tails and higher growth rates than thos...

By using both numerical and analytical approaches, we have shown that heterosis alone is not a mechanism for maintaining many alleles segregating at a locus. Even when all heterozygous are more fit than all homozygotes, the proportion of fitness arrays that will lead to a stable, feasible equilibrium of more than 6 or 7 alleles is vanishingly small. More alleles can be maintained if, in additio...

In plants, genes may disperse through both pollen and seeds. Here we provide a first theoretical study of the mechanisms and consequences of the joint evolution of pollen and seed dispersal. We focus on hermaphroditic self-compatible species distributed in structured populations, assuming island dispersal of pollen and seeds among small patches of plants within large populations. Three traits a...

Understanding the relative importance of heterosis and outbreeding depression over multiple generations is a key question in evolutionary biology and is essential for identifying appropriate genetic sources for population and ecosystem restoration. Here we use 2455 experimental crosses between 12 population pairs of the rare perennial plant Rutidosis leptorrhynchoides (Asteraceae) to investigat...

The genetic distance between hybridizing parents affects heterosis; however, the mechanisms for this remain unclear. Here we report that this genetic distance correlates with natural variation and epigenetic regulation of circadian clock-mediated stress responses. In intraspecific hybrids of Arabidopsis thaliana, genome-wide expression of many biotic and abiotic stress-responsive genes is diurn...

tomato as a highly nutritious vegetable crop is widely grown in the world. hybrid seed is preferably used for tomato production. identification of superior hybrid combination is one of the most important steps in the hybrid breeding programs. breeding of high yielding hybrids is expensive and involves testing large numbers of hybrid combinations in multi-environment trials. successful predictio...

The Brahman (American Zebu) has been evaluated in numerous crossbreeding studies throughout the Southern United States. Brahman females producing straightbred calves have usually been found to have a lower calving percentage, calf survival rate and weaning rate than other contemporary straightbreds, although they have been reported to be superior or competitive in some studies. Birth weights of...

The genetic basis of heterosis has not been elucidated. Previously, a congenic mouse strain with a 44-Mb genomic region of proximal chromosome 2 containing the allele derived from wild Mus musculus castaneus at Pbwg1, a quantitative trait locus (QTL) for body weight and growth, has been developed. In this study, to fine-map and characterize body weight QTLs on the congenic region, QTL analysis ...