Molecular genetics in aquaculture

Great advances in molecular genetics have deeply changed the way of doing research in aquaculture, as it has already done in other fields. The molecular revolution started in the 1980’s, thanks to the widespread use of restriction enzymes and Polymerase Chain Reaction technology, which allow to easily detect the genetic variability directly at DNA level. In aquaculture, the molecular data are used for several purposes, which can be clustered into two main groups. The first one, focused on individuals, includes the sex identification and parentage assignment, while the second one, focused on populations, includes the wide area of the genetic characterization, aimed at solving taxonomic uncertainties, preserving genetic biodiversity and detecting genetic tags. For the future, the increase in the number of molecular markers and the construction of high density genetic maps, and the implementation of genomic resources (including genome sequenciation), are expected to provide tools for the genetic improvement of aquaculture species through Marked Assisted Selection. In this review the characteristics of different types of molecular markers, along with their applications to a variety of aquaculture issues are presented.