Marker-assisted selection for aquaculture species

Genetic improvement in fish and other aquaculture species is a relatively new development. Excellent reviews on the progress in many species have been published (e.g., Gjedrem 1997, Benzie 1998, Hulata 2001). While the earliest genetic improvement has used standard methods of selection and cross breeding, developments in molecular genetics have now allowed for the development of molecular markers for parentage control and species identification (e.g., Heath et al. 1995, Norris et al. 2000, Martin and Soleto 2003). Also see Chapter 8 of this book. A number of mapping projects (Alcivar-Warren et al. 1997) have also led to the development of quantitative trait loci (QTL) projects designed to identify regions or genes and markers associated with specific traits in aquaculture species. Once identified these markers could then be used in marker-assisted selection (MAS). Hulata (2001) presented a review of developments that took place prior to the beginning of this decade. The purpose of this chapter is to provide the reader with some background and theory related to MAS and information as it pertains to some other species essential for food production and to present information on recent progress in the field of aquaculture.