What is MAS?

Individual fish show natural variation in the sequences of genes which can affect their value for farming.  Once the relationship between sequence variation and trait value is established then simple genetic tests can be used to select broodstock for breeding. This approach which is known as Marker Assisted Selection (MAS) has the potential to bring more rapid change in desirable characteristics than can be obtained with family selection alone. In MAS genetic assays are used to identify fish with favourable sequence variation in gene(s) which have a large effect on the trait of interest. Useful sequence variation could be in a gene directly coding for a protein required for the trait or in a regulatory sequence for that gene or in an associated gene in tight linkage. The most common kind of useful sequence variation are point mutations in single nucleotides leading to a change in amino acid sequence of the protein (so-called non-synonymous Single Nucleotide Polymorphisms or SNPs).

Xelect has a growing portfolio of genetic markers for broodstock selection in aquaculture fish species. Our markers allow fish breeders the possibility of selecting among thousands of potential parent fish, and only breeding from those with the optimal traits. Using markers has several key advantages:

  • Traits such as meat quality can be estimated without killing the fish, just by screening a DNA sample.
  • Selective breeding can be applied directly to the trait of interest while maintaining good genetic diversity in the rest of the genome.

Our R&D programme is dependent on collaborations with producers and breeders and we cordially invite contact from potential industrial partners. In addition to the possibility of developing major new broodstock selection markers we are also able to provide routine scientific services to the industry.