From Robert J. Spreitzer, University of Nebraska, August 2014

Phenotype: requires acetate, sensitive to light

Following 5-fluorodeoxyuridine treatment and ethyl-methanesulfonate mutagenesis of wild-type 2137 mt+ cells, colonies were screened for light-sensitive, acetate-requiring phenotypes (Spreitzer and Mets 1981). Mutant 11-3D displayed uniparental inheritance, and lacks photosystem II activity (Spreitzer and Mets 1981). Recombination tests showed that 11-3D is at the same locus (pst-u-1) as 8-36C, 10-4, 11-1A, 11-4D, and 12-3C (Spreitzer and Ogren 1983a). Because 8-36C, 11-1A, and 11-4D result from deletions in psbA (Bennoun et al 1986), 11-3D may also result from a psbA mutation. This strain was recovered from a cross between the original 11-3D mt+ (CC-2052) and pf2 mt- (from Levine), and has been maintained with acetate medium in darkness since 1980 to prevent selection for revertants and non-light-sensitive suppressors (Spreitzer and Ogren 1983b).

Chromosome: chloroplast


Bennoun P, Spierer-Herz M, Erickson J, Girard-Bascou J, Pierre Y, Delosme M, Rochaix JD (1986) Characterization of photosystem II mutants of Chlamydomonas reinhardii lacking the psbA gene. Plant Mol Biol 6:151-160

Spreitzer RJ, Mets L (1981) Photosynthesis-deficient mutants of Chlamydomonas with associated light-sensitive phenotypes. Plant Physiol 67:565-569

Spreitzer RJ, Ogren WL (1983a) Rapid recovery of chloroplast mutations affecting ribulosebisphosphate carboxylase/oxygenase in Chlamydomonas reinhardtii. Proc Natl Acad Sci USA 80:6293-6297

Spreitzer RJ, Ogren WL (1983b) Nuclear suppressors of the photosensitivity associated with defective photosynthesis in Chlamydomonas reinhardtii. Plant Physiol 71:35-39


  • Locus:
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, August 2014

Phenotype: requires acetate, sensitive to light

Following 5-fluorodeoxyuridine treatment and ethyl-methanesulfonate mutagenesis of wild-type 2137 mt+ cells, colonies were screened for light-sensitive, acetate-requiring phenotypes (Spreitzer and Mets 1981). Mutant 11-1A displayed uniparental inheritance, and lacks photosystem II activity (Spreitzer and Mets 1981). Recombination tests showed that 11-1A is at the same locus (pst-u-1) as 8-36C, 10-4, 11-3D, 11-4D, and 12-3C (Spreitzer and Ogren 1983a). Mutants 8-36C, 11-1A, and 11-4D were shown to result from deletions in psbA (Bennoun et al 1986). However, the extent of the deletions in 11-1A and 11-4D differs from that in 8-36C and FUD7 (CC-4147) (Bennoun et al 1986). This strain was recovered from a cross between the original 11-1A mt+ (CC-2051) and pf2 mt- (from Levine), and has been maintained with acetate medium in darkness since 1980 to prevent selection for revertants and non-light-sensitive suppressors (Spreitzer and Ogren 1983b).

Chromosome: chloroplast

Locus: psbA


Bennoun P, Spierer-Herz M, Erickson J, Girard-Bascou J, Pierre Y, Delosme M, Rochaix JD (1986) Characterization of photosystem II mutants of Chlamydomonas reinhardii lacking the psbA gene. Plant Mol Biol 6:151-160

Spreitzer RJ, Mets L (1981) Photosynthesis-deficient mutants of Chlamydomonas with associated light-sensitive phenotypes. Plant Physiol 67:565-569

Spreitzer RJ, Ogren WL (1983a) Rapid recovery of chloroplast mutations affecting ribulosebisphosphate carboxylase/oxygenase in Chlamydomonas reinhardtii. Proc Natl Acad Sci USA 80:6293-6297

Spreitzer RJ, Ogren WL (1983b) Nuclear suppressors of the photosensitivity associated with defective photosynthesis in Chlamydomonas reinhardtii. Plant Physiol 71:35-39


  • Locus:
  • psbA
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, August 2014

Phenotype: requires acetate, sensitive to light

Following 5-fluorodeoxyuridine treatment and ethyl-methanesulfonate mutagenesis of wild-type 2137 mt+ cells, colonies were screened for light-sensitive, acetate-requiring phenotypes (Spreitzer and Mets 1981). Mutant 11-4D displayed uniparental inheritance, and lacks photosystem II activity (Spreitzer and Mets 1981). Recombination tests showed that 11-4D is at the same locus (pst-u-1) as 8-36C, 10-4, 11-1A, 11-3D, and 12-3C (Spreitzer and Ogren 1983a). Mutants 8-36C, 11-1A, and 11-4D were shown to result from deletions in psbA (Bennoun et al 1986). However, the extent of the deletions in 11-1A and 11-4D differs from that in 8-36C and FUD7 (CC-4147) (Bennoun et al 1986). This strain was recovered from a cross between the original 11-4D mt+ and pf2 mt- (from Levine), and has been maintained with acetate medium in darkness since 1980 to prevent selection for revertants and non-light-sensitive suppressors (Spreitzer and Ogren 1983b).

Chromosome: chloroplast

Locus: psbA


Bennoun P, Spierer-Herz M, Erickson J, Girard-Bascou J, Pierre Y, Delosme M, Rochaix JD (1986) Characterization of photosystem II mutants of Chlamydomonas reinhardii lacking the psbA gene. Plant Mol Biol 6:151-160

Spreitzer RJ, Mets L (1981) Photosynthesis-deficient mutants of Chlamydomonas with associated light-sensitive phenotypes. Plant Physiol 67:565-569

Spreitzer RJ, Ogren WL (1983a) Rapid recovery of chloroplast mutations affecting ribulosebisphosphate carboxylase/oxygenase in Chlamydomonas reinhardtii. Proc Natl Acad Sci USA 80:6293-6297

Spreitzer RJ, Ogren WL (1983b) Nuclear suppressors of the photosensitivity associated with defective photosynthesis in Chlamydomonas reinhardtii. Plant Physiol 71:35-39


  • Locus:
  • psbA
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, August 2014

Phenotype: requires acetate, sensitive to light

Following 5-fluorodeoxyuridine treatment and ethyl-methanesulfonate mutagenesis of wild-type 2137 mt+ cells, colonies were screened for light-sensitive, acetate-requiring phenotypes (Spreitzer and Mets 1981). Mutant 10-3C displayed uniparental inheritance, and PSI-deficient fluorescence-induction kinetics (Spreitzer and Mets 1981). Recombination tests showed that 10-3C is at the same locus (pso-u-1) as 12-7 (Spreitzer and Ogren 1983a). Lee et al. (1996) reported that this PSI-deficient mutant could grow photoautotrophically, but the strain they used (CC-2046) likely reverted and has since been lost from the culture collection. This strain was recovered from a cross between the original 10-3C mt+ and pf2 mt- (from Levine), and has been maintained with acetate medium in darkness since 1980 to prevent selection for revertants and non-light-sensitive suppressors (Spreitzer and Ogren 1983b). Jake DeVries in Spreitzer’s group confirmed the original, acetate-requiring phenotype of this mutant as recently as August 2014.

Chromosome: chloroplast


Lee JW, Tevault CV, Owens TG, Greenbaum E (1996) Oxygenic photoautotrophic growth without photosystem I. Science 273:364-367

Spreitzer RJ, Mets L (1981) Photosynthesis-deficient mutants of Chlamydomonas with associated light-sensitive phenotypes. Plant Physiol 67:565-569

Spreitzer RJ, Ogren WL (1983a) Rapid recovery of chloroplast mutations affecting ribulosebisphosphate carboxylase/oxygenase in Chlamydomonas reinhardtii. Proc Natl Acad Sci USA 80:6293-6297

Spreitzer RJ, Ogren WL (1983b) Nuclear suppressors of the photosensitivity associated with defective photosynthesis in Chlamydomonas reinhardtii. Plant Physiol 71:35-39


  • Locus:
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, August 2014

Phenotype: requires acetate, sensitive to light

Following 5-fluorodeoxyuridine treatment and ethyl-methanesulfonate mutagenesis of wild-type 2137 mt+ cells, colonies were screened for light-sensitive, acetate-requiring phenotypes (Spreitzer and Mets 1981). Mutant 12-7 displayed uniparental inheritance, and PSI-deficient fluorescence-induction kinetics (Spreitzer and Mets 1981). Recombination tests showed that 12-7 is at the same locus (pso-u-1) as 10-3C (Spreitzer and Ogren 1983a). This strain was recovered from a cross between the original 12-7 mt+ and pf2 mt- (from Levine), and has been maintained with acetate medium in darkness since 1980 to prevent selection for revertants and non-light-sensitive suppressors (Spreitzer and Ogren 1983b).

Chromosome: chloroplast


Spreitzer RJ, Mets L (1981) Photosynthesis-deficient mutants of Chlamydomonas with associated light-sensitive phenotypes. Plant Physiol 67:565-569

Spreitzer RJ, Ogren WL (1983a) Rapid recovery of chloroplast mutations affecting ribulosebisphosphate carboxylase/oxygenase in Chlamydomonas reinhardtii. Proc Natl Acad Sci USA 80:6293-6297

Spreitzer RJ, Ogren WL (1983b) Nuclear suppressors of the photosensitivity associated with defective photosynthesis in Chlamydomonas reinhardtii. Plant Physiol 71:35-39


  • Locus:
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, August 2014

Phenotype: requires acetate, sensitive to light

Using established methods of 5-fluorodeoxyuridine treatment and ethyl-methanesulfonate mutagenesis of wild-type 2137 mt+ cells (Spreitzer and Mets 1981), colonies were screened for light-sensitive, acetate-requiring phenotypes. Mutant 15-1L displayed uniparental inheritance, and has an 80% decrease in Rubisco carboxylase activity and a 95% decrease in whole-chain electron transport (Spreitzer, unpublished). These pleiotropic alterations may arise from a defect in chloroplast protein synthesis. This strain has been maintained with acetate medium in darkness since it was recovered in 1982 to prevent selection for revertants and non-light-sensitive suppressors (Spreitzer and Ogren 1983b).

Chromosome: chloroplast


Spreitzer RJ, Mets L (1981) Photosynthesis-deficient mutants of Chlamydomonas with associated light-sensitive phenotypes. Plant Physiol 67:565-569

Spreitzer RJ, Ogren WL (1983b) Nuclear suppressors of the photosensitivity associated with defective photosynthesis in Chlamydomonas reinhardtii. Plant Physiol 71:35-39


  • Locus:
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, August 2014

Phenotype: requires acetate at 35 °C, temperature-conditional

The 67-12E chloroplast mutant was isolated by screening for temperature-conditional, acetate-requiring mutants (Spreitzer et al. 1988). It can grow on minimal medium at 25 °C, but dies on minimal medium at 35 °C. Mutant 67-12E has an 80% decrease in oxygen evolution and chlorophyll when grown at 35 °C (Spreitzer et al. 1988), but the genetic basis for defective photosynthesis is not known. This strain has been maintained with acetate medium in darkness to prevent selection for revertants or suppressors.

Chromosome: chloroplast


Spreitzer RJ, Al-Abed SR, Huether MJ (1988) Temperature-sensitive, photosynthesis-deficient mutants of Chlamydomonas reinhardtii. Plant Physiol 86:773-777


  • Locus:
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, August 2014

Phenotype: requires acetate at 35 °C, temperature-conditional

The 69-7M chloroplast mutant was isolated by screening for temperature-conditional, acetate-requiring mutants (Spreitzer et al. 1988). It can grow on minimal medium at 25 °C, but dies on minimal medium at 35 °C. Mutant 69-7M has 90% decreases in Rubisco carboxylase activity and chlorophyll when grown at 35 °C (Spreitzer et al. 1988). These pleiotropic alterations may arise from a defect in chloroplast protein synthesis. This strain was recovered from a cross between the original 69-7M mt+ and pf2 mt-, and has been maintained with acetate medium in darkness to prevent selection for revertants or suppressors.

Chromosome: chloroplast


Spreitzer RJ, Al-Abed SR, Huether MJ (1988) Temperature-sensitive, photosynthesis-deficient mutants of Chlamydomonas reinhardtii. Plant Physiol 86:773-777


  • Locus:
  • Chromosome:
  • chloroplast

From Robert J. Spreitzer, University of Nebraska, August 2014

Phenotype: requires acetate at 35 °C, temperature-conditional

The 69-7M chloroplast mutant was isolated by screening for temperature-conditional, acetate-requiring mutants (Spreitzer et al. 1988). It can grow on minimal medium at 25 °C, but dies on minimal medium at 35 °C. Mutant 69-7M has 90% decreases in Rubisco carboxylase activity and chlorophyll when grown at 35 °C (Spreitzer et al. 1988). These pleiotropic alterations may arise from a defect in chloroplast protein synthesis. This strain was recovered from a cross between the original 69-7M mt+ and pf2 mt-, and has been maintained with acetate medium in darkness to prevent selection for revertants or suppressors.

Chromosome: chloroplast


Spreitzer RJ, Al-Abed SR, Huether MJ (1988) Temperature-sensitive, photosynthesis-deficient mutants of Chlamydomonas reinhardtii. Plant Physiol 86:773-777


  • Locus:
  • Chromosome:
  • chloroplast

From Yan Zhou, Govindjee lab (& Manfredo Seufferheld), University of Illinois at Urbana-Champaign, July 2014

This knock-out mutant was constructed by insertional mutagenesis and is lacking in light-induced flagellar currents, which resulted in defects in both phototaxis and photoshock responses (Pazour, et al., 1995).


Pazour G, Sineshchekov O, Witman G (1995) Mutational analysis of the phototransduction pathway of Chlamydomonas reinhardtii. J Cell Biol 131:427-440

Chang RL, Ghamsari L, Manichaikul A, Hom EF, Balaji S, Fu W, Shen Y, Hao T, Palsson BØ, Salehi-Ashtiani K, Papin JA (2011) Metabolic network reconstruction of Chlamydomonas offers insight into light-driven algal metabolism. Mol Syst Biol 7:518

From Yan Zhou, Govindjee lab (& Manfredo Seufferheld), University of Illinois at Urbana-Champaign, July 2014

This spontaneous “immortal” mutant (IM) was discovered by Dr. Manfredo Seufferheld in University of Illinois at Urbana Champaign. It exhibited unique biophysical and biochemical characteristics compared to its progenitor ptx2 strain (CC-4909) and original background strain (CC-124) including higher biomass production under low light condition, higher oxygen evolution rate and production of protective compounds under certain conditions (Zhou, et al,.2014, submitted).

Biophysical and Metabolic Characterization of Mutant Chlamydomonas reinhardtii Strains to Improve Photosynthetic Efficiency of Algal Biofuel Systems under Light-Limited Conditions (Zhou, et al. 2014, submitted)

From Karin Komsic-Buchmann, Becker lab, University of Cologne, September 2014

This osmoregulatory mutant cannot survive under osmotic conditions below 140 mosM and should be grown on TAP supplemented with 64.6 mM sucrose and 0.2 g/L arginine. It was created by insertional mutagenesis of CC-3395 using pHyg3 and has a deletion in Chromosome 16 of unknown size; one known insertion flanking site (IFS) at 4,413,698.


Komsic-Buchmann K, Stephan LM, Becker B (2012) The SEC6 protein is required for contractile vacuole function in Chlamydomonas reinhardtii. J Cell Sci 125:2885-95


  • Locus:
  • Chromosome:
  • 16

From Karin Komsic-Buchmann, Becker lab, University of Cologne, September 2014

This osmoregulatory mutant cannot survive under osmotic conditions below 140 mosM and should be grown on TAP supplemented with 64.6 mM sucrose and 0.2 g/L arginine. It was created by insertional mutagenesis of CC-3395 using pHyg3 and has a deletion in Chromosome 17 of unknown size, one known insertion flanking site (IFS) at 6,748,893.


Komsic-Buchmann K, Stephan LM, Becker B (2012) The SEC6 protein is required for contractile vacuole function in Chlamydomonas reinhardtii. J Cell Sci 125:2885-95


  • Locus:
  • Chromosome:
  • 17

From Karin Komsic-Buchmann, Becker lab, University of Cologne, September 2014

This osmoregulatory mutant cannot survive under osmotic conditions below 140 mosM and should be grown on TAP supplemented with 64.6 mM sucrose and 0.2 g/L arginine. It was created by insertional mutagenesis of CC-3395 using pHyg3 and has a deletion in Chromosome 17 of 34.608 bp, from 6.771.512-6.806.120. In addition, it has longer flagella than the background strain.


Komsic-Buchmann K, Stephan LM, Becker B (2012) The SEC6 protein is required for contractile vacuole function in Chlamydomonas reinhardtii. J Cell Sci 125:2885-95


  • Locus:
  • Chromosome:
  • 17

From Karin Komsic-Buchmann, Becker lab, University of Cologne, September 2014

This is a complete rescue of Osmo75 (CC-4913) by transformation with pJR38-SEC6GFP. It is osmotolerant with normal length flagella.


Komsic-Buchmann K, Stephan LM, Becker B (2012) The SEC6 protein is required for contractile vacuole function in Chlamydomonas reinhardtii. J Cell Sci 125:2885-95


  • Locus:
  • Chromosome:
  • 17

From Karin Komsic-Buchmann, Becker lab, University of Cologne, September 2014

This is a complete rescue of Osmo75 (CC-4913) by transformation with pJR38-SEC6GFP. It is osmotolerant with normal length flagella.


Komsic-Buchmann K, Stephan LM, Becker B (2012) The SEC6 protein is required for contractile vacuole function in Chlamydomonas reinhardtii. J Cell Sci 125:2885-95


  • Locus:
  • Chromosome:
  • 17

From Karin Komsic-Buchmann, Becker lab, University of Cologne, September 2014

This is a complete rescue of Osmo75 (CC-4913) by transformation with pJR38-SEC6GFP. It is osmotolerant with normal length flagella.


Komsic-Buchmann K, Stephan LM, Becker B (2012) The SEC6 protein is required for contractile vacuole function in Chlamydomonas reinhardtii. J Cell Sci 125:2885-95


  • Locus:
  • Chromosome:
  • 17

From Karin Komsic-Buchmann, Becker lab, University of Cologne, September 2014

This is a complete rescue of Osmo75 (CC-4913) by transformation with pJR38-SEC6GFP. It is osmotolerant with normal length flagella.


Komsic-Buchmann K, Stephan LM, Becker B (2012) The SEC6 protein is required for contractile vacuole function in Chlamydomonas reinhardtii. J Cell Sci 125:2885-95


  • Locus:
  • Chromosome:
  • 17

From Karin Komsic-Buchmann, Becker lab, University of Cologne, September 2014

This is a complete rescue of Osmo75 (CC-4913) by transformation with pJR38-SEC6GFP. It is osmotolerant with normal length flagella.


Komsic-Buchmann K, Stephan LM, Becker B (2012) The SEC6 protein is required for contractile vacuole function in Chlamydomonas reinhardtii. J Cell Sci 125:2885-95


  • Locus:
  • Chromosome:
  • 17

From Karin Komsic-Buchmann, Becker lab, University of Cologne, September 2014

This is a complete rescue of Osmo75 (CC-4913) by transformation with pJR38-SEC6GFP. It is osmotolerant with normal length flagella.


Komsic-Buchmann K, Stephan LM, Becker B (2012) The SEC6 protein is required for contractile vacuole function in Chlamydomonas reinhardtii. J Cell Sci 125:2885-95


  • Locus:
  • Chromosome:
  • 17

From Karin Komsic-Buchmann, Becker lab, University of Cologne, September 2014

This is a complete rescue of Osmo75 (CC-4913) by transformation with pJR38-SEC6GFP. It is osmotolerant with normal length flagella.


Komsic-Buchmann K, Stephan LM, Becker B (2012) The SEC6 protein is required for contractile vacuole function in Chlamydomonas reinhardtii. J Cell Sci 125:2885-95


  • Locus:
  • Chromosome:
  • 17

From Karin Komsic-Buchmann, Becker lab, University of Cologne, September 2014

This is a complete rescue of Osmo75 (CC-4913) by transformation with pJR38-SEC6GFP. It is osmotolerant with normal length flagella.


Komsic-Buchmann K, Stephan LM, Becker B (2012) The SEC6 protein is required for contractile vacuole function in Chlamydomonas reinhardtii. J Cell Sci 125:2885-95


  • Locus:
  • Chromosome:
  • 17

From Karin Komsic-Buchmann, Becker lab, University of Cologne, September 2014

This is a complete rescue of Osmo75 (CC-4913) by transformation with pJR38-SEC6GFP. It is osmotolerant with normal length flagella.


Komsic-Buchmann K, Stephan LM, Becker B (2012) The SEC6 protein is required for contractile vacuole function in Chlamydomonas reinhardtii. J Cell Sci 125:2885-95


  • Locus:
  • Chromosome:
  • 17

From Karin Komsic-Buchmann, Becker lab, University of Cologne, September 2014

This is a complete rescue of Osmo75 (CC-4913) by transformation with pJR38-SEC6GFP. It is osmotolerant with normal length flagella.


Komsic-Buchmann K, Stephan LM, Becker B (2012) The SEC6 protein is required for contractile vacuole function in Chlamydomonas reinhardtii. J Cell Sci 125:2885-95


  • Locus:
  • Chromosome:
  • 17

From Robert J. Spreitzer, University of Nebraska, October 2014

Phenotype: requires elevated CO2 for photosynthetic growth, zeocin and spectinomycin resistant

This mutant was created by Fuqiao Xu in Spreitzer’s group by nuclear transformation of rbcLΔ/rbcSΔ-1A mt- (CC-4697) with a plasmid (pSS1-LSRR) that has the Chlamydomonas Rubisco small-subunit coding region of pSS1-ITP (Genkov et al. 2010) replaced with the codon-optimized sequence of Rhodospirillum rubrum Rubisco (Somerville and Somerville 1984). The mutant grows very slowly on minimal medium only when provided with 5% CO2 in air. It expresses only a low level of R. rubrum Rubisco. The strain has been maintained with acetate medium in darkness since its recovery in 2012.


Genkov T, Meyer M, Griffiths H, Spreitzer RJ (2010) Functional hybrid Rubisco enzymes with plant small subunits and algal large subunits: Engineered rbcS cDNA for expression in Chlamydomonas. J Biol Chem 285:19833-19841

Somerville CR, Somerville SC (1984) Cloning and expression of the Rhodospirillum rubrum ribulosebisphosphate carboxylase gene in E. coli. Molec Gen Genet 193:214-219


  • Locus:
  • rbcL, RBCS1
  • Chromosome:
  • chloroplast,2

From Robert J. Spreitzer, University of Nebraska, October 2014

Phenotype: requires elevated CO2 for photosynthetic growth, zeocin and spectinomycin resistant

This mutant was created by Fuqiao Xu in Spreitzer’s group by nuclear transformation of rbcLΔ/rbcSΔ-1A mt- (CC-4697) with a plasmid (pSS1-10SS-LSRR) that has the Chlamydomonas Rubisco small-subunit coding region of pSS1-ITP (Genkov et al. 2010) after residue 10 replaced with the codon-optimized sequence of Rhodospirillum rubrum Rubisco (Somerville and Somerville 1984). The mutant grows slowly on minimal medium only when provided with 5% CO2 in air. It expresses only a low level of R. rubrum Rubisco, but more than mutant rbcL∆/rbcS1-LSRR mt-. The strain has been maintained with acetate medium in darkness since its recovery in 2012.


Genkov T, Meyer M, Griffiths H, Spreitzer RJ (2010) Functional hybrid Rubisco enzymes with plant small subunits and algal large subunits: Engineered rbcS cDNA for expression in Chlamydomonas. J Biol Chem 285:19833-19841

Somerville CR, Somerville SC (1984) Cloning and expression of the Rhodospirillum rubrum ribulosebisphosphate carboxylase gene in E. coli. Molec Gen Genet 193:214-219


  • Locus:
  • rbcL, RBCS1
  • Chromosome:
  • chloroplast,2

From Robert J. Spreitzer, University of Nebraska, October 2014

Phenotype: requires elevated CO2 for photosynthetic growth

This mutant was created by Fuqiao Xu in Spreitzer’s group by nuclear transformation of rbcSΔ-T60-3 mt- (CC-4690) (Khrebtukova and Spreitzer 1996) with a plasmid (pSS1-10SS-LSRR) that has the Chlamydomonas Rubisco small-subunit coding region of pSS1-ITP (Genkov et al. 2010) after residue 10 replaced with the codon-optimized sequence of Rhodospirillum rubrum Rubisco (Somerville and Somerville 1984). The mutant grows slowly on minimal medium only when provided with 5% CO2 in air. It expresses only a low level of R. rubrum Rubisco, but more than mutant rbcL∆/rbcS1-LSRR mt-. The strain has been maintained with acetate medium in darkness since its recovery in 2012.


Genkov T, Meyer M, Griffiths H, Spreitzer RJ (2010) Functional hybrid Rubisco enzymes with plant small subunits and algal large subunits: Engineered rbcS cDNA for expression in Chlamydomonas. J Biol Chem 285:19833-19841

Khrebtukova I, Spreitzer RJ (1996) Elimination of the Chlamydomonas gene family that encodes the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase. Proc Natl Acad Sci USA 93:13689-13693

Somerville CR, Somerville SC (1984) Cloning and expression of the Rhodospirillum rubrum ribulosebisphosphate carboxylase gene in E. coli. Molec Gen Genet 193:214-219


  • Locus:
  • RBCS1
  • Chromosome:
  • 2

From Robert J. Spreitzer, University of Nebraska, October 2014

Phenotype: requires acetate, sensitive to light, spectinomycin resistant

This Rubisco rbcL knock-out mutant was created by Todor Genkov in Spreitzer’s group by replacing chloroplast rbcL of rbcS1-SSAT pf2 mt+ (CC-4764) with aadA. Whereas the original SSAT strain expresses functional Rubisco comprised of Chlamydomonas large subunits and Arabidopsis small subunits (Genkov et al. 2010), this mutant can express only Arabidopsis rbcS. The mutant was created to see whether functional Arabidopsis Rubisco could be expressed in Chlamydomonas. It has been cloned to homoplasmicity, and maintained with acetate medium in darkness since its isolation.


Genkov T, Meyer M, Griffiths H, Spreitzer RJ (2010) Functional hybrid Rubisco enzymes with plant small subunits and algal large subunits: Engineered rbcS cDNA for expression in Chlamydomonas. J Biol Chem 285:19833-19841


  • Locus:
  • rbcL, RBCS1, PF2
  • Chromosome:
  • chloroplast,2,11

From Robert J. Spreitzer, University of Nebraska, October 2014

Phenotype: requires acetate, sensitive to light, spectinomycin resistant

This Rubisco rbcL knock-out mutant was created by Todor Genkov in Spreitzer’s group by replacing chloroplast rbcL of rbcS1-SSSO pf2 mt+ (CC-4762) with aadA. Whereas the original SSSO strain expresses functional Rubisco comprised of Chlamydomonas large subunits and spinach small subunits (Genkov et al. 2010), this mutant can express only spinach rbcS. The mutant was created to see whether functional spinach Rubisco could be expressed in Chlamydomonas. It has been cloned to homoplasmicity, and maintained with acetate medium in darkness since its isolation.


Genkov T, Meyer M, Griffiths H, Spreitzer RJ (2010) Functional hybrid Rubisco enzymes with plant small subunits and algal large subunits: Engineered rbcS cDNA for expression in Chlamydomonas. J Biol Chem 285:19833-19841


  • Locus:
  • rbcL, RBCS1, PF2
  • Chromosome:
  • chloroplast,2,11

From Robert J. Spreitzer, University of Nebraska, October 2014

Phenotype: requires acetate, sensitive to light, spectinomycin resistant

This Rubisco rbcL knock-out mutant was created by Todor Genkov in Spreitzer’s group by replacing chloroplast rbcL of rbcS1-SSHA pf2 mt+ (CC-4766) with aadA. Whereas the original SSHA strain expresses functional Rubisco comprised of Chlamydomonas large subunits and sunflower small subunits (Genkov et al. 2010), this mutant can express only sunflower rbcS. The mutant was created to see whether functional sunflower Rubisco could be expressed in Chlamydomonas. It has been cloned to homoplasmicity, and maintained with acetate medium in darkness since its isolation.


Genkov T, Meyer M, Griffiths H, Spreitzer RJ (2010) Functional hybrid Rubisco enzymes with plant small subunits and algal large subunits: Engineered rbcS cDNA for expression in Chlamydomonas. J Biol Chem 285:19833-19841


  • Locus:
  • rbcL, RBCS1, PF2
  • Chromosome:
  • chloroplast,2,11