Whole genome sequencing of Strongylocentrotus purpuratus
Automated DNA extractions from tissues were performed using a bead-based and taxa-specific series of kits from Macherey-Nagel or Omega Bio-tek on an epMotion 5075 liquid handling robot.     Following extraction, DNA was assayed for purity, quality, and quantity using a NanoDrop 1000, agarose gel, and Qubit fluorescence quantification, respectively.     Individuals were sequenced in whole-genome libraries using SeqWell PlexWell kits, which is a modification of Illumina's Nextera/tagmentation technology.     Samples were first normalized and then tagmented, in which one of 24 sample-specific i7 indexes were ligated.     Individuals were then pooled into a single library in sets of 24 and ligated with one pool-specific i5 index.     Individuals are therefore dual indexed using 8bp indexes. Libraries were then amplified for 6 PCR cycles using the Kapa HiFi HotStart ReadyMix and then size-selected using SeqWell MAGwise Paramagnetic Beads.     Libraries were pooled equimolarly according to concentration and average fragment size for sequencing on a NovaSeq S4 6000 with paired-end 150 base pair reads at QB3 Genomics Vincent J. Coates Genomics Sequencing Lab.