Chlamydomonas Genetics Center, Duke University, 1983

Phenotype: requires acetate

From CC-1683 ac145 mt+ x CC-124 wild type mt-, 1983

The stock of this mutant (CC-571) obtained from Levine’s laboratory in 1978 by the Chlamydomonas Genetics Center showed a leaky acetate requirement but yielded clean isolates on crossing to wild type strains. The CC-1683 and CC-1684 derivatives were clearly acetate-requiring at the time they were created, but now are more difficult to score. Good isolates could probably be recovered again by crossing.


  • Locus:
  • AC145
  • Chromosome:
  • 10

From Jonathan Jarvik, Carnegie-Mellon University, November 1983

Phenotype: variable number of flagella

Mutation at the VFL3 locus causes defects in striated fibers associated with the basal body. Basal bodies are abnormally and variably spaced, and their orientation is disrupted. Cellular contents may be partitioned abnormally at cytokinesis. Marshall et al. reported that vfl3 mutants are defective in templated assembly of centrioles, but capable of de novo assembly.

In contrast to vfl2 mutants, the vfl3 mutant has normal levels of centrin and a stable nucleus-basal body connector. The flagella beat actively and waveform and frequency are normal, but the effective strokes can occur in any direction.


Wright RL, Chojnacki B, Jarvik JW (1983) Abnormal basal-body number, location, and orientation in a striated fiber-defective mutant of Chlamydomonas reinhardtii. J Cell Biol 96:1697-1707

Hoops HJ, Wright RL, Jarvik JW, Witman GB (1984) Flagellar waveform and rotational orientation in a Chlamydomonas mutant lacking normal striated fibers. J Cell Biol 98:818-824


  • Locus:
  • VFL3
  • Chromosome:
  • 6

From Jonathan Jarvik, Carnegie-Mellon University, November 1983

Phenotype: variable number of flagella

Please see CC-1686 for more information on the vfl3 mutant.


  • Locus:
  • VFL3
  • Chromosome:
  • 6

From Ruth Sager, Sidney Farber Cancer Institute, December 1983

This is Sager’s basic wild type strain. It has the wild type alleles at the NIT1 and NIT2 loci, and should be green in the dark. Sager’s original publication called it 21gr, but 21 gr has become the more prevalent usage over the years.

This strain was the source for most of the cDNA libraries, and subsequent EST sequences, in the Chlamydomonas Genome Project, and is our recommended choice for a wild type strain that grows on nitrate.


Sager R (1955) Inheritance in the Green Alga Chlamydomonas Reinhardi. Genetics 40:476-489

Pröschold T, Harris EH, Coleman AW (2005) Portrait of a species: Chlamydomonas reinhardtii. Genetics 170:1601-1610

From Ruth Sager, Sidney Farber Cancer Institute, December 1983

Phenotype: yellow in the dark

This is a mt- equivalent to Sager’s basic wild type strain (see CC-1690). It has the wild type alleles at the NIT1 and NIT2 loci and can grow on nitrate.

The original 6145c was selected as a strain that is yellow in the dark, carrying what was later described as the y1 mutant (see CC-735). This particular isolate has been grown in constant light for years and is probably mixed for y1 and its wild type allele.


  • Locus:
  • Y1
  • Chromosome:
  • 15

From Ruth Sager, Sidney Farber Cancer Institute, December 1983

Sager used this strain in her studies of methylation. Tests at the Chlamydomonas Center confirmed that like most of Sager’s strains, it can grow on nitrate medium.


Royer HD, Sager R (1979) Methylation of chloroplast DNAs in the life cycle of Chlamydomonas. Proc Natl Acad Sci U S A 76:5794-5798

From Charlene Forest, Brooklyn College, November 1983

Phenotype: does not mate when grown at high temperature

This is a temperature-sensitive, sex-limited mutant impaired in mating. When grown at 35 degrees, gam1 cells agglutinate with their mt+ partners and form a mating structure that appears normal in EM, but the mating structure fails to activate and no fusion occurs.


Forest CL, Togasaki RK (1975) Selection for conditional gametogenesis in Chlamydomonas reinhardi. Proc Natl Acad Sci U S A 72:3652-3655

Forest CL, Goodenough DA, Goodenough UW (1978) Flagellar membrane agglutination and sexual signaling in the conditional GAM-1 mutant of Chlamydomonas. J Cell Biol 79:74-84

Forest CL (1987) Genetic control of plasma membrane adhesion and fusion in Chlamydomonas gametes. J Cell Sci 88:613-621

Forest CL, Ojakian GK (1989) Mating Structure Differences Demonstrated by Freeze-Fracture Analysis of Fusion-Defective Chlamydomonas Gametes. The Journal of Protozoology 36:548-556

From Charlene Forest, Brooklyn College, November 1983

Phenotype: does not mate when grown at high temperature

This is a temperature-sensitive non-mating mutant with short flagella and disorganized 9 + 2 axonemal structure. It is expressed in both mating types.


Forest CL, Togasaki RK (1977) A selection procedure for obtaining conditional gametogenic mutants using a photosynthetically incompetent strain of Chlamydomonas reinhardi. Mol Gen Genet 153:227-230

Forest CL (1982) The relationship of flagellar length to sexual signalling in Chlamydomonas. Exp Cell Res 139:427-431

Forest CL (1983) Mutational disruption of the 9 + 2 structure of the axoneme of Chlamydomonas flagella. J Cell Sci 61:423-436

From Charlene Forest, Brooklyn College, November 1983

Phenotype: does not mate when grown at high temperature

This is a temperature-sensitive non-mating mutant with short flagella and disorganized 9 + 2 axonemal structure. It is expressed in both mating types.


Forest CL, Togasaki RK (1977) A selection procedure for obtaining conditional gametogenic mutants using a photosynthetically incompetent strain of Chlamydomonas reinhardi. Mol Gen Genet 153:227-230

Forest CL (1982) The relationship of flagellar length to sexual signalling in Chlamydomonas. Exp Cell Res 139:427-431

Forest CL (1983) Mutational disruption of the 9 + 2 structure of the axoneme of Chlamydomonas flagella. J Cell Sci 61:423-436

Chlamydomonas Genetics Center, Duke University, 1983

Phenotype: requires acetate

This strain was derived from a cross of CC-533 to wild type mt-.


Levine RP, Goodenough UW (1970) The genetics of photosynthesis and of the chloroplast in Chlamydomonas reinhardi. Annu Rev Genet 4:397-408


  • Locus:
  • AC24?
  • Chromosome:
  • 1

Chlamydomonas Genetics Center, Duke University, 1983

Phenotype: requires acetate

From CC-1024 pf1 x CC-977 ac31, 1983


  • Locus:
  • AC31
  • Chromosome:
  • 5

Chlamydomonas Genetics Center, Duke University, 1983

Phenotype: requires acetate and nicotinamide

From cross CC-14 nic15 x CC-552 ac177.


  • Locus:
  • AC177, NIC15 [ASO1]
  • Chromosome:
  • 12,13

Chlamydomonas Genetics Center, Duke University, 1983

Phenotype: requires acetate; motility impaired

From CC-1024 pf1 x CC-977 ac31, 1981

This strain provides markers at the distal ends of the left and right arms of the sparsely marked linkage group V.


  • Locus:
  • AC31, PF1 [RSP4]
  • Chromosome:
  • 5

Chlamydomonas Genetics Center, Duke University, 1983

Phenotype: requires acetate

From CC-596 ac28 x CC-919 wild type nit+ (no longer in the collection)

This strain provides a pair of markers on the left arm of linkage group III. See CC-1592 for the same combination in mt+.


  • Locus:
  • AC28, NIT2
  • Chromosome:
  • 3

Chlamydomonas Genetics Center, Duke University, 1983

Phenotype: requires arginine

This is a product of a cross of CC-46, a suppressed arg1 strain, to CC-125 wild type mt+. It may still carry a linked suppressor, since the phenotype is not as clean as CC-861, which is stringently arginine-requiring. For more information on the ARG1 locus, please see CC-47.


  • Locus:
  • ARG1
  • Chromosome:
  • 1

Chlamydomonas Genetics Center, Duke University, 1983

From CC-32 pab1 (nit1 nit2) mt+ x CC-919 wild type (NIT+) mt-, 1981

This strain provides markers for the left arm of linkage group III. It has the wild type allele at the unlinked nit1 locus.


  • Locus:
  • NIT2, PAB1
  • Chromosome:
  • 3

Chlamydomonas Genetics Center, Duke University, 1983

Phenotype: requires p-aminobenzoic acid

From CC-32 pab1 (nit1 nit2) mt+ x CC-919 wild type (NIT+) mt-

This strain can grow on nitrate.


  • Locus:
  • PAB1
  • Chromosome:
  • 3

Chlamydomonas Genetics Center, Duke University, 1983

From CC-255 nic13 can1 pyr1 act2 msr1 x CC-613 pf14, 1981.

The purpose of this cross was to couple pf14 and act2, easily scored markers on the right arm of linkage group VI. The msr1 marker came through from the CC-255 parent, but the nic13, can1 and pyr1 markers did not.


  • Locus:
  • ACT2 [RPL36a], MSR1, PF14 [RSP3]
  • Chromosome:
  • 1,6

Chlamydomonas Genetics Center, Duke University, 1983

Phenotype: antibiotic resistant (erythromycin); motility impaired

From CC-1125 pf22 (no longer in the collection) x ery3 arg2 mt- (a product from CC-78 x CC-639), 1981

This strain provides markers that span the centromere on linkage group I. Please see CC-1733 for the same combination in mating type plus, CC-73 for more information on the ERY3 locus, and CC-2495 for more information on PF22.


  • Locus:
  • ERY3, PF22
  • Chromosome:
  • 1

Chlamydomonas Genetics Center, Duke University, 1983

Phenotype: antibiotic resistant (erythromycin)

The ery2a allele was obtained in Bogorad’s laboratory after mutagenesis of a 137c wild-type strain with ethyl methanesulfonate. CC-895 ery2a mt+ (which is no longer in the collection) was crossed to CC-124 wild type mt-, and a ery2a mt- product from this cross was crossed to CC-125 wild type mt+ to give CC-1711.

This strain provides better viability in crosses than the original CC-895. Since ery2 is easily scored and is a good marker for the sparsely populated linkage group XIV, having this in a strain that crosses well seemed desirable.

The ery2 mutants as a group are resistant to 100 micrograms/ml erythromycin on minimal medium, and are cold-sensitive.

Bowers et al. showed that the ERY2 locus corresponds to the gene encoding chloroplast ribosomal protein L22.


Mets LJ, Bogorad L (1971) Mendelian and uniparental alterations in erythromycin binding by plastid ribosomes. Science 174:707-709

Mets LJ, Bogorad L (1972) Altered chlorplast ribosomal proteins associated with erythromycin-resistant mutants in two genetic systems of Chlamydomonas reinhardi. Proc Natl Acad Sci U S A 69:3779-3783

Davidson JN, Hanson MR, Bogorad L (1978) Erythromycin resistance and the chloroplast ribosome in Chlamydomonas reinhardi. Genetics 89:281-297

Bowers AK, Keller JA, Dutcher SK (2003) Molecular markers for rapidly identifying candidate genes in Chlamydomonas reinhardtii. Ery1 and ery2 encode chloroplast ribosomal proteins. Genetics 164:1345-1353


  • Locus:
  • ERY2 [RPL22]
  • Chromosome:
  • 13

Chlamydomonas Genetics Center, Duke University, 1983

Phenotype: requires acetate; antibiotic resistant (cycloheximide)

From CC-1103 act1 pf12 (no longer in the collection) x CC-523 ac12.

This strain, which has wild type motility, provides two easily-scored markers on the right arm of linkage group II. It was used in several subsequent crosses to order the pf and lf markers on this group.

Please see CC-1589 for more information on the act1 mutation, and CC-522 for more information on ac12.


  • Locus:
  • AC12, ACT1
  • Chromosome:
  • 2

Chlamydomonas Genetics Center, Duke University, 1983

Phenotype: requires acetate; antibiotic resistant (anisomysin, spectinomycin)

From the following crosses: CC-399 ani1 x CC-801 spr1, and a product of that cross x CC-530 ac17.

This was derived from an attempt to order the linked markers ani1 and spr1 relative to the centromere, using ac17 as a reference.


  • Locus:
  • AC17, PDR1, SPR1
  • Chromosome:
  • 3,16

Chlamydomonas Genetics Center, Duke University, 1983

Phenotype: requires acetate and nicotinamide

From CC-864 nic13 mt+ x CC-571 ac145 mt- (later discarded; please see CC-1683 for information on this mutation)

This strain couples two fairly closely linked markers on linkage group X.


  • Locus:
  • AC145, NIC13 [NSN1]
  • Chromosome:
  • 10

Chlamydomonas Genetics Center, Duke University, 1983

Phenotype: requires acetate (suppressed); antibiotic and inhibitor resistant (neamine, paromomycin, pyrithiamine, streptomycin)

From a cross of CC-1109 pr1 pyr1 nr1 msr1 sr1 mt+ (a strain that is no longer in the collection) x CC-553 ac-200 mt-.

The acetate requiring phenotype was easily scored in this strain at the time it was constructed, but has now become at least partially suppressed. The strain is still useful for the four resistance markers, all on different linkage groups. Please see CC-89 for information on pr1, CC-146 for nr1, CC-112 for sr1, and CC-28 for pyr1 and msr1.


  • Locus:
  • AC200, NR1, PR1, PYR1, SR1
  • Chromosome:
  • 4,8,9,10

Chlamydomonas Genetics Center, Duke University, 1983

Phenotype: requires acetate; antibiotic resistant (spectinomycin)

From CC-1243 ac215 x CC-801 spr1

This strain couples two markers on linkage group XVIII.

CC-1243 and CC-1244, which are no longer in the collection, were mt+ and mt- isolates of the mutant described by Spreiter and Mets as a11-6C. It was subsequently named ac215, as the next locus number in the ac series. This mutant is deficient in photosystem I and is light-sensitive.

Spreitzer and Mets reported relatively close linkage of the ac215 (11-6C) mutant to its centromere (ac/y1 19:15:0). Crosses at the Chlamydomonas Genetics Center assigned this locus to linkage group XVIII.


Spreitzer RJ, Mets L (1981) Photosynthesis-deficient Mutants of Chlamydomonas reinhardii with Associated Light-sensitive Phenotypes. Plant Physiol 67:565-569


  • Locus:
  • AC215, SPR1
  • Chromosome:
  • 16

Chlamydomonas Genetics Center, Duke University, 1983

Phenotype: requires acetate (somewhat suppressed)

The ac209 mutation was UV-induced in Levine’s laboratory. This mutant was listed by Levine and Goodenough (1970) as nonphotosynthetic. The specific defect has not been determined.

From a cross at Duke in 1982. The ac209 marker in this strain ultimately traces back to CC-557 ac209 mt-, received from Ursula Goodenough in 1978 and no longer in the collection.

In a test cross in 1983, the ac209 marker was scorable only as a color difference rather than absolute acetate requirement, but was clearly segregating 2:2. This is the only ac209 isolate now in the collection.

The AC209 locus was originally placed on the left arm of linkage group I based on a cross in Levine’s laboratory of ac206 x ac14 (39:0:130). However, other crosses by Levine and colleagues, as well as crosses of ac209 isolates at the Chlamydomonas Genetics Center did not show the expected linkage to group I markers.


Levine RP, Goodenough UW (1970) The genetics of photosynthesis and of the chloroplast in Chlamydomonas reinhardi. Annu Rev Genet 4:397-408

Chlamydomonas Genetics Center, Duke University, 1983

Phenotype: requires acetate

From CC-125 wild type x CC-554 ac207

This strain is easier to score than the original CC-554.


  • Locus:
  • AC207
  • Chromosome:
  • 3

Chlamydomonas Genetics Center, Duke University, 1983

Phenotype: requires acetate

From CC-1024 pf1 x CC-1250 ac18 (no longer in the collection; came from the same cross as CC-1249)

This was recovered as a cleaner acetate-requiring strain from a mapping cross of the original ac18 stock. Please see CC-1249 for more information on the ac18 mutation.


  • Locus:
  • AC18
  • Chromosome:
  • 5

Chlamydomonas Genetics Center, Duke University, 1983

Phenotype: requires acetate on copper-containing medium.

From CC-1173 y7 x CC-556 ac208

The ac208 mutant has been thoroughly studied by Merchant and colleagues. We have two stocks of this mutant in mating type minus, this one and CC-556; in recent years we have generally sent out CC-1729, although both are listed in the core collection.

Please see CC-556 for reference citations and additional information.


  • Locus:
  • AC208 [PETE]
  • Chromosome:
  • 3

Chlamydomonas Genetics Center, Duke University, 1983

Phenotype: requires nicotinamide; antibiotic and inhibitor resistant (neamine, pyrithiamine, streptomycin)

This strain contains good mapping markers for four linkage groups, in a nitrate-utilizing background. It was derived from a cross of CC-599 nic1 to a derivative of the CC-1144 multiply marked strain. This strain can grow on nitrate.


  • Locus:
  • NIC1, NR1, PYR1, SR1
  • Chromosome:
  • 4,8,9,14