Parent Prochlorococcus NATL2A replicate 2, Illumina WGS
Cells from 5 mL of culture were first pelleted by centrifugation at 12,000 xg for 10 minutes. Genomic DNA was extracted using a previously published phenol/chloroform procedure (Wilson 2001) with the addition of a 100% chloroform extraction at the end to remove residual phenol contaminates. To minimize shearing, samples were shaken briefly by hand (no vortex use), centrifugation time and speed (3 min at 16,000 xg) were minimized, and used wide bore tips.  Libraries were constructed using the NextEra XT kit (Illumina) on an automated Tecan Freedom EVO robotics platform, starting from 1ng of input DNA. The resulting libraries were sequenced using an Illumina NextSeq 500, generating between 7.6 million  10.7 million 150+150nt paired-end reads from each sample (Supplementary Table 1).