A French consortium, coordinated by INRA and including CEA (Genoscope), CNRS and the Ecoles Normales Supérieures of Paris and Lyon, has sequenced and analysed the genome of the rainbow trout (Oncorhynchus mykiss), which constitutes the first published genome of a salmonid (salmons and trouts family). This sequence, published on April 22, 2014 in Nature Communications, introduces a new scenario for the evolution of vertebrate genomes and opens up new prospects for selection in aquaculture.
The rainbow trout is an important aquaculture species bred all around the world. It belongs to the salmonid family, of which numerous species are of major agronomical and ecological interest. The trout is also a model for research and the most studied
A precious resource for genome evolution
This sequence gives new insights into the evolution of vertebrate genomes. Complete genome duplications are events that profoundly molded the content and structure of genomes, including the human genome. Unfortunately, the mechanisms underlying the evolution of a genome after such an event happens are not well understood in animals, and in particular the steps taking place in the tens of millions of years following duplication.
The rainbow trout is a particularly interesting species as its genome was completely duplicated relatively recently (100 million years ago), in the common ancestor of all current salmonids. The surprising conclusion of this study is that the evolution of vertebrate genomes after full duplication is a slow and gradual process. Despite the 100 million years that have passed since this event, the two copies remain well conserved. Not only do the general structure of the two copies remained similar, but the content in genes is highly conserved, and many of the ancestral genes are still there and functional. This result calls into question the commonly accepted hypothesis that the evolution of a genome following a complete duplication implies a rapid evolution of its structure and gene content.tces in aquaculture
This sequence opens up great perspectives in the development of a more efficient and sustainable aquaculture, by accelerating the analysis of important breeding traits, the identification of genes and the implementation of selection programs that are more efficient.
Story source: INRA press release, 22 Apr 2014
Journal reference: Camille Berthelot et al. The rainbow trout genome provides novel insights into evolution after whole-genome duplication in vertebrates. Nature Communications 5, Article number: 3657 doi:10.1038/ncomms4657