Rainbow trout Oncorhynchus mykiss Whole Genome Assembly. Oncorhynchus mykiss

The rainbow trout is a major aquaculture species of great economic importance raised in both hemispheres and on all continents. It is the main freshwater aquaculture fish species in many countries and a member of the Salmonid family that is of major ecological interes worldwide. In addition to the 2 rounds of whole genome duplication (WGD) shared by all vertebrates, and the teleost-specific 3rd WGD (Ts3R) that occurred 300 Myrs ago, salmonids species have undergone an additional round of WGD; the Salmonid-specific genome duplication (Ss4R) that occurred approximately 50 Myrs ago. Genome duplications are believed to be driving forces of evolution. They are also believed to be rapidly followed by major genomic rearrangements leading to re-diploidization. To date, these mechanisms have been poorly investigated due to the lack of genome sequence in a species undergoing re-diploidization after WGD. Here we present the draft sequence of the 2.4-Gb genome of an Oncorhynchus mykiss doubled-haploid (YY) genotype allowing subsequent analysis of genome evolution after recent WGD.