RAD sequencing of adult Labrus bergylta
Approximately 1g of purified DNA per sample was digested with the restriction endonuclease SphI (GCATG|C recognition site). Modified Illumina adapters containing five nucleotides of barcode sequence unique (P1 adapters) to an individual in the library were ligated with T4 DNA ligase to allow sample multiplexing. The pooled samples were then sheared using a Covaris S-Series ultrasonicator and size-selected to isolate DNA fragments spanning 300500bp by agarose gel electrophoresis. The NEBNext Ultra DNA II Library Prep Kit  was then used for End Repair and dA-Tailing, followed by the P2 Adaptor Ligation step to enable selective PCR. The samples were amplified using the NEBNext DNA Library Prep Master Mix Set by 10 cycles of PCR.