Chromosomal rearrangements can be triggered by recombination between distinct but related regions. Brassica napus (AACC; 2n = 38) is a recent allopolyploid species whose progenitor genomes are widely replicated. In this article, we analyze the extent to which chromosomal rearrangements originate from homeologous recombination during meiosis of haploid B. napus (n = 19) by genotyping progenies o...

To date, all linkage maps of hexaploid oat (Avena sativa L.) have been constructed using recombinant inbred lines (RILs). Doubled haploids (DHs), however, have the advantage over RILs of their comprehensive homozygosity. DHs have been used for mapping in several cereal species, but in oats the production of large DH populations has only recently become an option. A linkage map of hexaploid oat ...

Barley is an attractive vehicle for producing recombinant protein, since it is a readily transformable diploid crop species in which doubled haploids can be routinely generated. High amounts of protein are naturally accumulated in the grain, but optimal endosperm-specific promoters have yet to be perfected. Here, the oat GLOBULIN1 promoter was combined with the legumin B4 (LeB4) signal peptide ...

The increased usage of whole-genome selection (WGS) and other molecular evaluation methods in plant breeding relies on the ability to genotype a very large number of untested individuals in each breeding cycle. Many plant breeding programs evaluate large biparental populations of homozygous individuals derived from homozygous parent inbred lines. This structure lends itself to parent-progeny im...

Tobacco (Nicotiana tabacum L.) has become a model system for tissue culture and genetic engineering over the past several decades and continues to remain the 'Cinderella of Plant Biotechnology', An ill vitro culture medium (Murashige and Skoog, 1962), based on the studies with tobacco tissue cultures, has now been widely used as culture medium formulation for hundreds of plant species. Studies ...

Generation of clonal zebrafish will facilitate large-scale genetic screening and help us to overcome other biological and biotechnological challenges due to their isogenecity. However, protocols for the development of clonal lines have not been optimized. Here, we sought to develop a novel method for generation of clonal zebrafish by androgenesis induced by cold shock. Androgenetic zebrafish do...

A study was made of tissues of diploid and haploid Xenopus laevis larvae by electron microscopy. The comparison of the two types of larvae was both quantitative and qualitative. Haploid cells contain fewer similarly sized mitochondria and/or cilia (compared with the diploid), commensurate with their smaller cell size. Cellular differentiation is retarded in haploids and the degree of retardatio...

Little is known about the genetics controlling the rate of embryonic development in salmonids, despite the fact that this trait plays an important role in the life history of wild and cultured stocks. We investigated the genetics of embryonic development rate by performing an analysis of quantitative trait loci (QTL) on two families of androgenetically derived doubled haploid rainbow trout prod...

HEN Habrobracon eggs are X-rayed at metaphase I and subsequently fertiw l i z e d , the decreased hatchability is attributed to dominant lethal mutation, in the same sense in which the term is used when sperm are irradiated. This is justified by WHITING'S demonstration (1946, 1948, 1949, 1950, 1955) that cytoplasmic injury is not lethal a t the doses employed. In unfertilized eggs, which develo...