Article Figures & Data
Figures
- Fig. 1.
First records of the occurrence ofProchlorococcus. (A) Electron microscope photograph of “type II cells” from deep samples of the North Atlantic ocean. Reprinted from reference 63 with permission of the publisher. ce, cell envelope; pb, polyhedral bodies; th, thylakoids. Scale bar, 0.5 μm. (B) Analysis of a pigment extract obtained by normal-phase HPLC showing the “unknown Chl a derivative,” indicated by a star. Reprinted from reference37 with permission of the publisher.
- Fig. 2.
Analysis of natural Prochlorococcuspopulations by flow cytometry. (Top) Side scatter (a function of cell size) plotted against red fluorescence of chlorophyll. (Bottom) Orange fluorescence of phycoerythrin plotted against red fluorescence of chlorophyll. All scales are 4-decades logarithmic from 1 to 10,000 (arbitrary units). (Left) Typical surface-layer sample (45 m, deep Equatorial Pacific, 7°S, 150°W, collected 10 November 94).Synechococcus is easily distinguished fromProchlorococcus by its orange phycoerythrin fluorescence. (Middle) Typical deep sample (105 m deep, Equatorial Pacific, 7°S, 150°W, collected 10 November 94). Synechococcus is virtually absent, and the chlorophyll fluorescence ofProchlorococcus is much higher than near the surface (compare the fluorescence of Prochlorococcus and that of the standard beads). Note also the weak orange fluorescence displayed byProchlorococcus at this depth. (Right) Example of twoProchlorococcus populations coexisting at the same depth (80 m deep, Mediterranean Sea, 37°5′N, 16°52′E, collected 20 June 1996).
- Fig. 3.
Locations of some of the availableProchlorococcus strains (see Table 1).
- Fig. 4.
Electron micrographs of longitudinal and cross sections of Prochlorococcus strain MIT9313 showing tightly appressed thylakoids at the periphery of the cell. Scale bar, 0.1 μm. Unpublished photographs courtesy of C. Ting, J. King, and S. W. Chisholm.
- Fig. 5.
Vertical distributions from bright and dimProchlorococcus populations in the subtropical Pacific Ocean off Hawaii. The insert represents the vertical profile of side scatter and red chlorophyll fluorescence of the totalProchlorococcus population measured by flow cytometry. Adapted from reference 17 with permission of the publisher.
- Fig. 6.
Diagram showing the thylakoid proteins inProchlorococcus and their putative organization by homology to the photosynthetic apparatus of cyanobacteria. The proteins whose genes have been sequenced partially or totally are shown in dark gray (see Table 3), and those which have been characterized only by immunoblotting (35, 90, 132) are shown in light gray. Although phycoerythrin is present in some strains such as SS120, it is not clear whether it is integrated in phycobilisomes, which, if present, would be very scarce. PS I is probably organized in trimers (35), but only one monomer is shown. The insert shows a detail of the Pcb protein which includes six transmembrane hydrophobic domains. For the electron transport chain, only the cytochromeb6-f complex is shown because the existence of other components (such as NADH dehydrogenase and plastoquinone) has not been demonstrated yet. Other probable components of the photosynthetic apparatus such as cytochrome oxidase or ATP synthase are not shown either, since they are still uncharacterized inProchlorococcus. Abbreviations: CP, chlorophyll-protein complex; Cyt, cytochrome; OEC, oxygen evolving complex.
- Fig. 7.
Concentrations Prochlorococcus integrated over the water column throughout the world oceans. Based on data from Table 5.
- Fig. 8.
Relationship between Prochlorococcusintegrated concentrations and surface temperature (A) and surface nitrate concentrations (B). Based on data from Table 5.
- Fig. 9.
Vertical distributions of Prochlorococcus (A) and Synechococcus (B). Based on data from Table 5.
- Fig. 10.
Typical vertical distributions ofProchlorococcus and Synechococcus. (A and B) Surface layer maximum. (C and D) Deep maximum. (E and F) Uniform distribution over the euphotic zone. (A and B) North tropical Atlantic, EUMELI3 cruise (129). (A) EU site, off the coast of Mauritania (20°N, 18°W). (B) MESO site (18°N, 21°W). (C) North Atlantic 30°N, 23°W (11). (D) Eastern Mediterranean Sea, 34°N 18°E, MINOS cruise (176). (E) Equatorial Pacific 150°W, 5°S (174). (F) Tropical Pacific 150°W, 16°S (174). (D and F) Prochlorococcus chlorophyll fluorescence was too weak to be detected at the surface.
- Fig. 11.
Phylogenetic relationship betweenProchlorococcus isolates and cyanobacteria inferred from 16S rRNA gene sequences. Reprinted from reference 166with permission of the publisher.
Tables
- Table 1.
Prochlorococcus strains isolated in culture for which published data are available
Strain Derived clone Other name Origin Datea Latitude Longitude Depth (m) Isolator Remarks Reference(s) SARG LG Sargasso Sea 30/5/88 28°59′N 64°21′W 120 B. Palenik First strain to be isolated 131 SS120 CCMP 1375 L. R. Moore Obtained by serial dilution 20, 107 PCC 9511 R. Rippka First axenic strain 143 MED DV NW Mediterranean 8/1/89 43°12′N 6°52′E 5 D. Vaulot, F. Partensky 131 MED4 CCMP 1378 L. R. Moore Obtained by serial dilution 20, 107 NATL1 FP12 N Atlantic 1/4/90 37°39′N 40°1′W 30 F. Partensky 131 NATL2 FP5 N Atlantic 1/4/90 38°59′N 40°33′W 30 F. Partensky 145, 166 MIT9107 S Pacific 8/8/91 14°60′S 134°60′W 25 J. A. Dusenberry 166 TATL 1 EUM11 E Tropical Atlantic 19/10/91 20°57′N 31°6′W 20 F. Partensky 145, 166 TATL 2 EUM17 E Tropical Atlantic 21/10/91 20°25′N 31°8′W 30 F. Partensky 145, 166 GP2 W Pacific 10/9/92 8°32′N 136°31′E 150 A. Shimada 155, 156 SB Sugura Bay, Japan 21/10/92 35°0′N 138°30′E 40 A. Shimada 156, 157 PAC 1 N Tropical Pacific 1/4/92 22°45′N 158°0′W 100 L. Campbell 145, 166 MIT9201 S Pacific 26/9/92 11°60′S 145°25′W 0 B. Binder 106 MIT9202 S Pacific 26/9/92 11°60′S 145°25′W 79 B. Binder 106 MIT9211 Equatorial Pacific 10/4/92 0 140°W 83 R. J. Olson 106 MIT9215 Equatorial Pacific 3/9/92 0 140°W 0 B. Binder 106 MIT9302 Sargasso Sea 15/7/93 34°45′N 66°11′W 100 L. Moore Sorted by flow cytometry 108 MIT9303 Sargasso Sea 15/7/93 34°45′N 66°11′W 100 L. Moore Sorted by flow cytometry 108, 166 MIT9312 N Atlantic 17/7/93 37°30′N 68°14′W 135 L. Moore Sorted by flow cytometry 108 MIT9313 N Atlantic 17/7/93 37°30′N 68°14′W 135 L. Moore Sorted by flow cytometry 108 AS9601 Arabian Sea 1/11/95 19°12′N 67°10′E 50 R. J. Olson 150 ↵a Day/month/year.
- Table 2.
Composition of media used for growing Prochlorococcusa
Component Concn of component inb: CPTC-based (A) K/10-Cu (B) PC (C) PRO2 (D) PCR-S11 (E) Nutrients Urea 20 μM 50 μM 100 μM NH4ClB,C,D or (NH4)2SO4E 50 μM 50 μM 50 μM 400 μM β-glycerol-phosphateA,C (or NaH2PO4)B,D,E 10 μM 10 μM 10 μM 10 μM 50 μM Buffer HEPES 1 mM Chelator/trace metals CPTC 100 μM EDTA-Na2 11.7 μM 11.7 μM 1.2 μM 8 μM FeSO4A or FeCl3B,C,D,E 0.1 μM 1.2 μM 1.2 μM 1.2 μM 8 μM MnCl2A,B,C,D or MnSO4E 10 nM 90 nM 90 nM 90 nM 30 nM ZnCl2B,C,D or ZnSO4E 8 nM 8 nM 8 nM 3 nM CoCl2B,C,D [or Co(NO3)2]E 5 nM 5 nM 5 nM 1.5 nM Na2MoO4A,B,C,D or (NH4)6 Mo7O24E 10 nM 3 nM 3 nM 3 nM 1.5 nM Mo Na2SeO3B,C,D or SeO2E 10 nM 10 nM 10 nM 1.5 nM NiSO4 or NiCl2D,E 10 nM 10 nM 1.5 nM Na2WO4 0.3 nM KBr 3 nM KI 1.5 nM Cd(NO3)2 1.5 nM CuSO4 1.5 nM Cr(NO3)3 0.3 nM VOSO4 0.3 nM KaI(SO4)2 3 nM H3BO3 150 nM Vitamins Thiamine-HCl 10 μM Biotin 50 nM B12 50 nM 7 nM - Table 3.
Genes sequenced in Prochlorococcus
Category Gene name Molecule encoded Localization or function EMBL/GenBank accession no. Reference(s) Photosynthesis cpeY Phycoerythrobilin, phycourobilin lyase? Light harvesting? AJ001230 52 cpeZ Phycoerythrobilin, phycourobilin lyase? Light harvesting? AJ001230 52 mpeX Bile pigment biosynthesis, coupling? Light harvesting? AJ001230 52 orf463 Assembly of light-harvesting structures? Light harvesting? AJ001230 52 pcb Chl a2 and Chl b2antenna PS II antenna U57660 , U57661 77 petB b -type cytochrome Cytochrome b6-f complex AF001487 –AF001489 166 petD Subunit IV Cytochrome b6-f complex AF001487 –AF001489 166 cpeA Phycoerythrin III α subunit Light harvesting? Z68890 , AJ001230 55 cpeB Phycoerythrin III β subunit Light harvesting? Z68890 , AJ001230 55 ppeC Linker polypeptide of phycoerythrin Light harvesting? Z92525 , AJ001230 54 psaA PsaA PS I core 167 psaB PsaB PS I core 167 psaF Subunit PsaF of PS I Binding of plastocyanin? 167 psaI Subunit PsaI of PS I Trimerization of PS I Z98595 ,AJ002427 168 psaJ Subunit PsaF of PS I Binding of plastocyanin? 167 psaL Subunit PsaL of PS I Trimerization of PS I Z98595 , AJ002427 168 psbA D1 PS II core Z49201 57 psbB CP47 Internal antenna of PS II AF001481 –AF001485 166 rbcL Large subunit of Rubisco Carbon assimilation U93857 , U93858 52, 133, 155 General metabolism aroC Chorismate synthase Amino acid metabolism Z49201 51 aspA Aspartoacylase Amino acid metabolism Z80110 51 cpn60 Chaperonin-60 Protein folding Z37730 52 dapA Dihydrodipicolinate synthase Amino acid metabolism Z37733 , Z68126 95 rpoC1 DNA-dependent RNA polymerase Biosynthesis of RNA Z11160 125 rnpB RNase P ribozyme RNA processing Y12789 , AJ001135 53 rnc RNase III RNA processing AJ001135 52 rrn 16S rRNA Protein synthesis X63140 ,AF001466 – AF001476 165, 166 trnR Transfer RNA arginine (CCU) Translation Y12789 ,AJ001135 53 Nutrient uptake pstS Phosphate-binding protein Phosphorus assimilation U75514 146 Cell cycle dnaA DnaA DNA replication U44977 139 ftsZ FtsZ Cell division AJ011025 58 uvrD DNA helicase DNA replication and DNA repair processes AJ001230 52 - Table 4.
Codon usage in P. marinus CCMP 1375 (6,365 codons)a
Amino acid First and second positions No. of occurrences at third position A C G T Ala GC 247 70 34 255 Arg CG 27 16 5 52 Arg AG 121 41 Asn AA 89 222 Asp GA 86 259 Cys TG 21 43 Gln CA 158 77 Glu GA 244 101 Gly GG 152 107 66 167 His CA 44 131 Ile AT 145 72 294 Leu TT 236 106 Leu CT 119 36 29 199 Lys AA 239 100 Phe TT 123 190 Pro CC 103 22 10 123 Ser TC 124 27 20 150 Ser AG 65 103 Thr AC 111 65 11 137 Tyr TA 50 111 Val GT 115 40 36 203 Stop TA 6 4 Stop TG 6 Total 2,153 933 640 2,639 ↵a The absolute number of occurrences of each codon was computed from 17 genes (see Table 3 for references):aspA, cpeY, cpeZ cpn60,dapA, dnaA, mpeX, pcb,ppeA, ppeB, psaA, psaB,psbA, ppeC, rnc, uvrD, andorf463. The noninformative Trp and Met codons are omitted. For uvrD, only the first 518 codons are known.
- Table 5.
Oceanographic data used to construct Fig. 7 to 10
Ocean or sea Area Cruise Ship Yr(s) Months Reference Atlantic Ocean North Atlantic 87022 CSSHudson 1987 June 88 88026 CSSHudson 1988 Sept 87 89003 CSSBaffin 1989 Apr 86 NIOZ Natl 89 RVTyro 1989 Aug–Sept 179 91001 CSSHudson 1991 Apr 81 92037 CSSHudson 1992 Sept 83 93002 CSSHudson 1993 May 83 NOAA 93 NOAA Malcolm Baldbridge 1993 July–Aug 11 Delaware 95 RV Cape Henlopen 1995 Apr 84 95016 CSSHudson 1995 July 84 Sargasso Sea CHLOMAX NOSuroit 1987 Sept–Oct 116 Lopez 96 Launch 1995 June 85 Tropical Atlantic EUMELI 3 NOAtalante 1991 Oct 129 EUMELI 4 NOAtalante 1992 June 129 EUMELI 5 NOAtalante 1992 Dec 129 Indian Ocean Arabian Sea Arabian TTN043 RVThomson 1995 Jan 14 Arabian TTN045 RVThomson 1995 Mar–Apr 14 Arabian TTN049 RVThomson 1995 July–Aug 117 Indian Ocean and Red Sea NIOZ Indian 1992–1993 May–Feb 181 Pacific Ocean Equatorial Pacific EQPAC TT007 RVThomson 1992 Feb–Mar 74 EQPAC TT008 RVThomson 1992 Mar–Apr 7 EQPAC TT008D RVThomson 1992 Mar–Apr 27 EQPAC TT011 RVThomson 1992 Aug–Sept 74 EQPAC TT012 RVThomson 1992 Sept–Oct 27 SURTROPAC 17 NONoroit 1992 Aug 8 OLIPAC NOAtalante 1994 Nov 115 FLUPAC NOSuroit 1994 Sept–Oct 115 Tropical Pacific HOT Moana Wave 1990–1994 15 Coast of Japan Suruga Bay Boat 1992–1993 May–Oct 157 South Pacific Chile 95 RVSonne 1995 June 85 West Tropical Pacific Australia RVSohgen-Maru 1990 Nov–Dec 154 Mediterranean Sea EROS Discovery 89 HMSDiscovery 1989 Jan 178 EROS Bannock 89 Bannock 1989 July 128 POEM 91 RV Bilim/RV Shikmona 1991 Oct 89 Eddy 92 RV Shikmona 1992 Mar 193 EROS Valdivia 92 Valdivia 1992 Mar 97 EROS Discovery 93 HMSDiscovery 1993 July 4 Malaga 93 Launch 1993 Jan 33 MINOS NOSuroit 1995 Jun 176
