Sequencing and characterization of the anadromous steelhead (Oncorhynchus mykiss) transcriptome and its application for expression analyses in hatchery and wild fish

Steelhead are the anadromous (ocean-going) form of Oncorhynchus mykiss and their populations have been steadily declining. These large-scale population declines have led to the design and implementation of numerous salmon hatchery programs that either enhance fishery production or supplement endangered runs. However, it has recently been found that even first-generation hatchery salmon exhibit much lower fitness in the wild than their wild-born counterparts. Furthermore, the differences in fitness have been demonstrated to be heritable and the result of inadvertent domestication selection (i.e., adaptation to the captive environment). Thus, identifying the loci under selection and the traits involved could be of tremendous value to hatchery managers. Salmonids are the focus of a vast amount of research due to their immense economic, ecological and cultural importance.