Populational studies of yellowfin tuna (Thunnus albacares) and Serra Spanish mackerel (Scomberomorus brasiliensis) (Perciformes: Scombridae) using the reduced representation library technique

Abstract

Studies of single-nucleotide polymorphisms (SNPs), using the technology of next-generation sequencing (NGS), enable us to reach a great level of cost-effective genotyping of up to thousands of individuals. Within the new technologies exist methodologies employing restriction enzymes, as is the case with the technique of reduced representation library (RRL) which allow a notable reduction in genome sequencing. Upon RRL is possible to sequence a fraction of the common genome of different populations and/or closely related species in the same run using labeled nucleotides, connected to the adapters used to construct the libraries. These methodologies are being applied in marine fish, which are excellent models for studies of adaptation and population analyzes due to their large geographical distribution and their large population sizes. Inside the fish caught for fresh consumption and processed fish stand out the family Scombridae, known generically as tuna, bonito, saws, etc., they constitute an important world fishery resource, being one of the most representative groups within the food industry, and captured and marketed throughout its distribution area. These fish are under extreme anthropogenic pressure and there is an urgent need for the use of genetic tools to identify the structure and boundaries of populations to enable better stock management and conservation. Thus, we intend to find specific SNPs, using the technique of RRL, for two populations of two species: yellowfin tuna and serra Spanish mackerel, collected at two distant points from the coast of Brazil (Rio Grande do Norte and Santa Catarina), in order to seek and analyze the diversity and genetic differentiation of populations in these two geographical areas. The results will provide a better identification of existing populations and delineation of priority areas for conservation and management programs. (AU)