Fig. 1: Ecotypes of the phototroph Prochlorococcus demonstrate distinct diel patterns in replication (R_Obs), whereas ecotypes of the heterotroph SAR11 show consistent replication across the day-night cycle.

Here, we examine the A HLI, B HLII, C clade Ia, and D clade Ib ecotypes. Point shape corresponds to C13.5 (squares), I07N (circles), and I09N (triangles) samples (with at least 5× coverage of single-copy core genes (SCCG) prior to rarefaction). Point whiskers represent the standard error of replication estimates across 30x rarefactions (standard error was low and is largely obscured by the points). The black trend line represents the central tendency of R_Obs patterns as characterized by a loess curve (“loess,” R “stats” package, span = 0.22) with 90% confidence intervals shaded in gray. White and blue background shading represents the light and dark diel cycle, respectively, with sunrise occurring at ~06:00 and sunset occurring at ~18:00. Insets: Single-copy core gene read coverage mapped to reference genome position for the station with the highest slope. The purple line is the terminus of replication. The red line is the bi-linear fit to the coverage pattern.