Heterosis refers to the phenomenon in which an F1 hybrid exhibits enhanced growth or agronomic performance. However, previous theoretical studies on heterosis have been based on bi-parental segregating populations instead of F1 hybrids. To understand the genetic basis of heterosis, here we used a subset of F1 hybrids, named a partial North Carolina II design, to perform association mapping for ...

The F1 hybrid between a channel catfish female (Ictalurus punctatus) × a blue catfish (I. furcatus) male outperforms both parental species in most environments. However, reproductive isolating mechanisms between the species made it difficult to mass produce the F1 hybrid for commercialization until recent improvements in hormone usage. This study was undertaken to mix the genomes of the 2 speci...

Hybridization creates novel gene combinations that may generate important evolutionary novelty, but may also reduce existing adaptation by interrupting inherent biological processes, such as genotype-environment interactions. Hybridization often causes substantial change in patterns of gene expression, which, in turn, may cause phenotypic change. Rainbow trout (Oncorhynchus mykiss) and cutthroa...

Diploid hybrids of Saccharomyces cerevisiae and its closest relative, Saccharomyces paradoxus, are viable, but the sexual gametes they produce are not. One of several possible causes of this gamete inviability is incompatibility between genes from different species--such incompatible genes are usually called "speciation genes." In diploid F1 hybrids, which contain a complete haploid genome from...

Gene flow from genetically modified (GM) crops to wild relatives might affect the evolutionary dynamics of weedy populations and result in the persistence of escaped genes. To examine the effects of this gene flow, the growth of F1 hybrids that were formed by pollinating wild soybean (Glycine soja) with glyphosate-tolerant GM soybean (G. max) or its non-GM counterpart was examined in a greenhou...

Interspecific amphihaploid and amphidiploid hybrids between Nicotiana glauca Grah. (2n = 24) and N. tabacum L. (2n = 48) cultivars BY 103 and K 326 were analysed. F1 amphihaploids (2n = 36) were viable and completely self- and cross-sterile, and mostly univalents were present during meiosis (with pairing range from 0 to 5). In some meiocytes, meiotic irregularities were observed, such as sporad...

In this study, the intergeneric hybrids F1, F2, BC1F1, BC1F2, and BC2F1 from Elytrigia elongata and Triticum aestivum crosses were produced to study their chromosome pairing behavior. The average E. elongata chromosome configuration of the two F1 hybrids agreed with the theoretical chromosome configuration of 21I+7II, indicating that the genomic constitution of this F1 hybrid was ABDStStEeEbEx....

A combination of ovarian grafting and fostering was used to study the effects of preand postnatal maternal factors on adult behaviour. Inbred mice (BALB/c and C57BL/6) and F1 hybrids were compared to assess differential sensitivity to early maternal effects. In addition to the peculiar behavioural profile of BALB mice, results revealed the existence of a cognitive process in mice and confirmed ...

Yak are crossed with Bos taurus and Bos indicus cattle, including common local cattle breeds (via natural service) and via artificial insemination of frozen-thawed semen from improved breeds (e.g. Holstein Friesian). Female hybrids reach puberty and mate a year earlier than pure yaks. Nonpregnant F1 females usually have several estrus cycles in the same season and will generally calve every yea...

Interspecific hybridisation between hexaploid and tetraploid wheat species leads to the development of F1 pentaploid hybrids with unique chromosomal constitutions. Pentaploid hybrids derived from bread wheat (Triticum aestivum L.) and durum wheat (Triticum turgidum spp. durum Desf.) crosses can improve the genetic background of either parent by transferring traits of interest. The genetic varia...