Whole genome bisulfite sequencing of Picocholorum soloecismus across several days of its growth cycle

Epigenetic modifications have not been well characterized in most microalgae species, particularly those used for biofuel production. We report the first analysis of DNA methylation of the species Picocholorum soloecismus across its growth cycle using whole-genome bisulfite sequencing. DNA methylation occurs in all three cytosine contexts (CpG, CHH, CHG) in P. soloecismus. While global DNA methylation is low overall (~1.15% of the 15 MB genome), methylation occurs appreciable quantities (12.1%) in CpG dinucleotides in a bimodal distribution. The P. soloecismus genome becomes hypomethylated during the growth cycle (across several days in culture). 5-aza-2'-deoxycytidine (5AZA) treatment was used to alter DNA methylation patterns, which resulted in altered algal physiology and site specific changes in CpG DNA methylation. Overall design: whole genome bisulfite sequencing on days 4, 5, 6, 7, and 10 in culture in control and 20 uM 5-aza-2'deoxycytidine treated cultures (biological triplicates) for a total of 30 sequencing runs