Table A1.

Characteristics of organisms used in this study

Organism	Abbreviation	Light adaptation	Size (Mb)	Gene number	Source
Prochlorococcus MED4	PMED4	HL(I)	1.66	1757	GI:33772317
Prochlorococcus MIT9515	PMC	HL(I)	1.7	1948	GI:123965234
Prochlorococcus AS9601	PMB	HL(II)	1.67	1964	GI:123967536
Prochlorococcus MIT9301	PMG	HL(II)	1.64	1949	GI:126695337
Prochlorococcus MIT9312	PMI	HL(II)	1.71	1855	GI:78778385

The source of genome sequence is the National Center for Biotechnology Information (NCBI), with the given accession number. The other source is Joint Genome Institute (JGI). The HL represents high-light-adapted ecotypes