Strains

From William Inwood and Sydney Kustu, UC Berkeley, January 2005

Phenotype: inhibitor resistant (methylammonium)

This is a spontaneous methylammonium-resistant mutant isolated in the 4A+ background (CC-4051). CR03 contains a 558-bp insertion at 294 relative to the translational start of the AMT4 gene, encoding an ammonium transport protein. There is a duplication of the sequence CTGTTTCC at either end of the insertion, which is itself bounded by a perfect 17-bp inverted repeat. Otherwise, the AMT4 gene in the CR03 strain is identical to that of the parental strain. Congruent with the location of the lesion relative to the AMT4 coding region, CR03 is less resistant to methylammonium and shows higher residual methylammonium uptake than other amt4 strains.

Kim KS, Feild E, King N, Yaoi T, Kustu S, Inwood W (2005) Spontaneous mutations in the ammonium transport gene AMT4 of Chlamydomonas reinhardtii. Genetics 170:631-644

• Locus:
• AMT4
• Chromosome:
• 13

From William Inwood and Sydney Kustu, UC Berkeley, January 2005

Phenotype: inhibitor resistant (methylammonium)

This is a spontaneous methylammonium-resistant mutant isolated in the CC-125 background. The CR05 and CR43 mutants are similar in showing very low levels of uptake of radioactive methylammonium. In contrast to most of the other mutants studied by Kim et al., these two mutants do not appear to have alterations in the AMT4 gene.

Kim KS, Feild E, King N, Yaoi T, Kustu S, Inwood W (2005) Spontaneous mutations in the ammonium transport gene AMT4 of Chlamydomonas reinhardtii. Genetics 170:631-644

From William Inwood and Sydney Kustu, UC Berkeley, January 2005

Phenotype: inhibitor resistant (methylammonium)

This is a spontaneous methylammonium-resistant mutant isolated in the CC-125 background. CR03 contains a 558-bp insertion at 294 relative to the translational start of the AMT4 gene, encoding an ammonium transport protein. There is a duplication of the sequence CTGTTTCC at either end of the insertion, which is itself bounded by a perfect 17-bp inverted repeat. Otherwise, the AMT4 gene in the CR03 strain is identical to that of the parental strain. Congruent with the location of the lesion relative to the AMT4 coding region, CR03 is less resistant to methylammonium and shows higher residual methylammonium uptake than other amt4 strains.

Kim KS, Feild E, King N, Yaoi T, Kustu S, Inwood W (2005) Spontaneous mutations in the ammonium transport gene AMT4 of Chlamydomonas reinhardtii. Genetics 170:631-644

• Locus:
• AMT4
• Chromosome:
• 13

From William Inwood and Sydney Kustu, UC Berkeley, January 2005

Phenotype: inhibitor resistant (methylammonium)

This is a spontaneous methylammonium-resistant mutant isolated in the 4A+ background (CC-4051). The CR39 mutant carries a 300-bp deletion of portions of exon 5 and intron 5 of the AMT4 gene. Assuming normal splicing of the remaining transcript, this lesion leads to translation of a truncated protein of 385 correct amino acids (terminating within predicted transmembrane segment 10) followed by nine incorrect amino acids from intron 5 sequence. The lesion creates an Amt4 null phenotype.

Kim KS, Feild E, King N, Yaoi T, Kustu S, Inwood W (2005) Spontaneous mutations in the ammonium transport gene AMT4 of Chlamydomonas reinhardtii. Genetics 170:631-644

• Locus:
• AMT4
• Chromosome:
• 13

From William Inwood and Sydney Kustu, UC Berkeley, January 2005

Phenotype: inhibitor resistant (methylammonium)

This is a spontaneous methylammonium-resistant mutant isolated in the 4A+ background (CC-4051). The CR40 mutant carries a large insert near the end of exon 1 of the AMT4 gene, which was identified by Kim et al. as a TOC1 transposon. Low residual transcript levels for cells grown on arginine (3′ end of AMT4) were not elevated above those for cells grown on ammonium, and Kim et al. concluded that transcription of the 3′ end of AMT4 is probably being driven from within TOC1. The lesion in CR40 is an amt4 null allele.

Kim KS, Feild E, King N, Yaoi T, Kustu S, Inwood W (2005) Spontaneous mutations in the ammonium transport gene AMT4 of Chlamydomonas reinhardtii. Genetics 170:631-644

• Locus:
• AMT4
• Chromosome:
• 13

From William Inwood and Sydney Kustu, UC Berkeley, January 2005

Phenotype: inhibitor resistant (methylammonium)

This is a spontaneous methylammonium-resistant mutant isolated in the 4A+ background (CC-4051). The CR41 and CR45 mutants are closely linked to one another, and may be alleles at the same locus. Both are sensitive to chloroquine and are unable to grow on hypoxanthine as a nitrogen source.

Kim KS, Feild E, King N, Yaoi T, Kustu S, Inwood W (2005) Spontaneous mutations in the ammonium transport gene AMT4 of Chlamydomonas reinhardtii. Genetics 170:631-644

From William Inwood and Sydney Kustu, UC Berkeley, January 2005

Phenotype: inhibitor resistant (methylammonium)

This is a spontaneous methylammonium-resistant mutant isolated in the 4A+ background (CC-4051). CR42 carries a portion of the 5.66 kb TOC1 retrotransposon, inserted near the end of exon 1 of the AMT4 gene at a position 34 bp downstream of the site of the TOC1 insertion in CR40 and 4 bp downstream of the 2-bp deletion in CR02. The lesion leads to translation of 70 correct amino acids and one incorrect amino acid and an Amt4 null phenotype.

Kim KS, Feild E, King N, Yaoi T, Kustu S, Inwood W (2005) Spontaneous mutations in the ammonium transport gene AMT4 of Chlamydomonas reinhardtii. Genetics 170:631-644

• Locus:
• AMT4
• Chromosome:
• 13

From William Inwood and Sydney Kustu, UC Berkeley, January 2005

Phenotype: inhibitor resistant (methylammonium)

This is a spontaneous methylammonium-resistant mutant isolated in the 4A+ background (CC-4051). The CR05 and CR43 mutants are similar in showing very low levels of uptake of radioactive methylammonium. In contrast to most of the other mutants studied by Kim et al., these two mutants do not appear to have alterations in the AMT4 gene.

Kim KS, Feild E, King N, Yaoi T, Kustu S, Inwood W (2005) Spontaneous mutations in the ammonium transport gene AMT4 of Chlamydomonas reinhardtii. Genetics 170:631-644

• Locus:
• AMT4
• Chromosome:
• 13

From William Inwood and Sydney Kustu, UC Berkeley, January 2005

Phenotype: inhibitor resistant (methylammonium)

This is a spontaneous methylammonium-resistant mutant isolated in the 4A+ background (CC-4051). CR04 contains a single base pair substitution, which changes a GGC codon (glycine) to GAC (aspartate) in exon 5 of the AMT4 gene. The change occurs at amino acid residue 236 within putative transmembrane segment 5. Based on the level of resistance to methylammonium and methylammonium uptake characteristics, this non-conservative change in a critical region appears to result in an amt4 null allele.

Kim KS, Feild E, King N, Yaoi T, Kustu S, Inwood W (2005) Spontaneous mutations in the ammonium transport gene AMT4 of Chlamydomonas reinhardtii. Genetics 170:631-644

• Locus:
• AMT4
• Chromosome:
• 13

From William Inwood and Sydney Kustu, UC Berkeley, January 2005

Phenotype: inhibitor resistant (methylammonium)

This is a spontaneous methylammonium-resistant mutant isolated in the 4A+ background (CC-4051). The CR41 and CR45 mutants are closely linked to one another, and may be alleles at the same locus. Both are sensitive to chloroquine and are unable to grow on hypoxanthine as a nitrogen source.

Kim KS, Feild E, King N, Yaoi T, Kustu S, Inwood W (2005) Spontaneous mutations in the ammonium transport gene AMT4 of Chlamydomonas reinhardtii. Genetics 170:631-644

From William Inwood and Sydney Kustu, UC Berkeley, January 2005

Phenotype: inhibitor resistant (methylammonium)

This is a spontaneous methylammonium-resistant mutant isolated in the 4A+ background (CC-4051). CR46 has an insertion of the Tcr1 transposon immediately upstream of the AMT4 translational start, leading to a duplication of the target sequence GTCGCAGG at -15 to -8. The insert is within the 5′ untranslated leader of the AMT4 transcript and CR46 retains residual Amt4 function.

Kim KS, Feild E, King N, Yaoi T, Kustu S, Inwood W (2005) Spontaneous mutations in the ammonium transport gene AMT4 of Chlamydomonas reinhardtii. Genetics 170:631-644

• Locus:
• AMT4
• Chromosome:
• 13

From William Inwood and Sydney Kustu, UC Berkeley, January 2005

Phenotype: inhibitor resistant (methylammonium)

This is a spontaneous methylammonium-resistant mutant isolated in the 4A+ background (CC-4051). CR47 has a 10-bp deletion in exon 5 of the AMT4 gene, leading to a frameshift and a truncated translation product of 357 correct amino acids (terminating in putative transmembrane segment 9) followed by 10 incorrect amino acids. CR47 has an Amt4 null phenotype.

Kim KS, Feild E, King N, Yaoi T, Kustu S, Inwood W (2005) Spontaneous mutations in the ammonium transport gene AMT4 of Chlamydomonas reinhardtii. Genetics 170:631-644

• Locus:
• AMT4
• Chromosome:
• 13

From William Inwood and Sydney Kustu, UC Berkeley, January 2005

Phenotype: inhibitor resistant (methylammonium)

This is a spontaneous methylammonium-resistant mutant isolated in the 4A+ background (CC-4051). The CR48 rmutant has a substitution of a guanine residue for the highly conserved adenine in the right splice junction of intron 2 of the AMT4 transcript. The change shifts the splice site 17 bp to the right, leading to an altered transcript and introducing a frameshift, as verified by sequence analysis of cDNA. The resulting translation product has 85 correct amino acids followed by 32 incorrect amino acids and the same translation stop as in CR02. CR48 has an Amt4 null phenotype.

Kim KS, Feild E, King N, Yaoi T, Kustu S, Inwood W (2005) Spontaneous mutations in the ammonium transport gene AMT4 of Chlamydomonas reinhardtii. Genetics 170:631-644

• Locus:
• AMT4
• Chromosome:
• 13

From William Inwood and Sydney Kustu, UC Berkeley, January 2005

Phenotype: inhibitor resistant (methylammonium)

This is a spontaneous methylammonium-resistant mutant isolated in the 4A+ background (CC-4051). CR49 has an insertion of a 5-kb fragment of a TOC1 transposon into exon 5 of the AMT4 gene, encoding an ammonium transport protein. This insertion leads to translation of a truncated Amt4 polypeptide of 430 amino acid residues. Strain CR49 has an Amt4 null phenotype.

Kim KS, Feild E, King N, Yaoi T, Kustu S, Inwood W (2005) Spontaneous mutations in the ammonium transport gene AMT4 of Chlamydomonas reinhardtii. Genetics 170:631-644

• Locus:
• AMT4
• Chromosome:
• 13

From William Inwood and Sydney Kustu, UC Berkeley, January 2005

Phenotype: inhibitor resistant (methylammonium)

This is a spontaneous methylammonium-resistant mutant isolated in the 4A+ background (CC-4051). CR50 has a single base-pair change, from T to A on the sense strand, near the end of intron 4 of the AMT4 gene, encoding an ammonium transport protein. The change has apparently introduced a new splice site near the end of intron 4 by changing CUG to CAG in the transcript. Kim et al. reported that the sequence of the new spliced message obtained by RT-PCR shows the addition of CCC CUC CCC GCC CCG CCC CUC CAG to the major mRNA. Translation of this modified transcript results in the change of one amino acid and the addition of eight new residues in putative transmembrane segment 4 . In addition to the major transcript there is a minor transcript (10-20% of the total) that is normal. CR50 retains residual Amt4 function.

Kim KS, Feild E, King N, Yaoi T, Kustu S, Inwood W (2005) Spontaneous mutations in the ammonium transport gene AMT4 of Chlamydomonas reinhardtii. Genetics 170:631-644

• Locus:
• AMT4
• Chromosome:
• 13

From William Inwood and Sydney Kustu, UC Berkeley, January 2005

This is the background strain of the methylammonium resistant mutants isolated in the Kustu lab (CC-4036 – CC-4052). This strain originated in Jean-David Rochaix’s lab, and is a 137c derivative selected for rapid growth on acetate in the dark. It carries the nit1 and nit2 mutations, and is unable to utilize nitrate.

Kim KS, Feild E, King N, Yaoi T, Kustu S, Inwood W (2005) Spontaneous mutations in the ammonium transport gene AMT4 of Chlamydomonas reinhardtii. Genetics 170:631-644

From William Inwood and Sydney Kustu, January 2005

Phenotype: inhibitor resistant (methylammonium)

This is a spontaneous methylammonium-resistant mutant isolated in the 4A+ background (CC-4051). CR02 carries a 2-bp deletion near the end of exon 1 of the AMT4 gene, encoding an ammonium transport protein. The mutation leads to a frame shift after correct translation of the first 68 amino acids, ending within predicted transmembrane segment 1. These are followed by 53 incorrect amino acids and a stop. The normal protein is 499 amino acids in length. This lesion in AMT4 appears to be a null allele.

Kim KS, Feild E, King N, Yaoi T, Kustu S, Inwood W (2005) Spontaneous mutations in the ammonium transport gene AMT4 of Chlamydomonas reinhardtii. Genetics 170:631-644

• Locus:
• AMT4
• Chromosome:
• 13

From Yuqing Hou and George Witman, University of Massachusetts Medical School, 2004

Phenotype: impaired motility

This is strain TBD9-1, an insertional mutant in the D1bLIC light intermediate chain of cytoplasmic dynein 1b.

Hou Y, Pazour GJ, Witman GB (2004) A Dynein Light Intermediate Chain, D1bLIC, Is Required for Retrograde Intraflagellar Transport. Mol Biol Cell 15:382-4394

• Locus:
• NIT1
• Chromosome:
• 9

From Yuqing Hou and George Witman, University of Massachusetts Medical School, 2004

Phenotype: impaired motility

This is strain YH43, a product from a cross of the original d1blic mutant (TBD9 1, CC-4053) to CC-124.

Hou Y, Pazour GJ, Witman GB (2004) A Dynein Light Intermediate Chain, D1bLIC, Is Required for Retrograde Intraflagellar Transport. Mol Biol Cell 15:382-4394

• Locus:
• NIT1
• Chromosome:
• 9

From Gary Small, University of South Dakota, 2004

Phenotype: UV sensitive

This is Small’s strain 72E2, which was derived by mutagenesis of a cw15 strain with the plasmid pSP124s and selecting for UV sensitivity. The transformation resulted in a 57 kb deletion spanning the REX1 gene and an ornithine decarboxylase.

Cenkci B, Petersen JL, Small GD (2003) REX1, a novel gene required for DNA repair. J Biol Chem 278:22574-22577

• Locus:
• REX1
• Chromosome:
• 1

From Gary Small, University of South Dakota, 2004

Phenotype: UV sensitive

This is a product (72E2/1) from a backcross of CC-4055 rex1 72E2 to CC-125 . It appears to have a normal cell wall, i.e. has lost the cw15 mutation of the parent strain.

Cenkci B, Petersen JL, Small GD (2003) REX1, a novel gene required for DNA repair. J Biol Chem 278:22574-22577

• Locus:
• REX1
• Chromosome:
• 1

From Gary Small, University of South Dakota, 2004

Phenotype: UV sensitive; requires arginine

This strain was derived by crossing the original rex1 (72E2) strain (CC-4055) to a cw15 arg7 strain. It was used for complementation studies using the cloned rex1 gene.

Cenkci B, Petersen JL, Small GD (2003) REX1, a novel gene required for DNA repair. J Biol Chem 278:22574-22577

• Locus:
• REX1
• Chromosome:
• 1

From Gary Small, University of South Dakota, 2004

Small commented that this strain is not blocked in excision of pyrimidine dimers. This may be a transformant of the original rex1 mutant with a construct containing only part of the bicistronic REX1 locus, as described in the paper by Cencki et al.

Cenkci B, Petersen JL, Small GD (2003) REX1, a novel gene required for DNA repair. J Biol Chem 278:22574-22577

From Gary Small, University of South Dakota, 2004

Small commented that this strain is blocked in excision of pyrimidine dimers. This may be a transformant of the original rex1 mutant with a construct containing only part of the bicistronic REX1 locus, as described in the paper by Cencki et al.

Cenkci B, Petersen JL, Small GD (2003) REX1, a novel gene required for DNA repair. J Biol Chem 278:22574-22577

From Gary Small, University of South Dakota, 2004

Small commented that this strain is not blocked in excision of pyrimidine dimers. This may be a transformant of the original rex1 mutant with a construct containing only part of the bicistronic REX1 locus, as described in the paper by Cencki et al.

Cenkci B, Petersen JL, Small GD (2003) REX1, a novel gene required for DNA repair. J Biol Chem 278:22574-22577

From Peter Luykx, University of Miami, June 2005, his strain PL142

Phenotype: deficient in osmoregulation

This is the osm1 mutant in a nit1 background (please see CC-3699 for more information on this mutant). This strain should be maintained on TAP medium supplemented with 0.06M sucrose or lactose. This strain has the wild-type allele at the NIT2 locus.

• Locus:
• NIT1
• Chromosome:
• 9

From Peter Luykx, University of Miami, June 2005, his PL143

Phenotype: deficient in osmoregulation

This is the osm3 mutant in a nit1 background. (Please see CC-3701 for more information on this mutant.) This strain should be maintained on TAP medium supplemented with 0.06M sucrose or lactose. This strain has the wild-type allele at the NIT2 locus.

• Locus:
• NIT1
• Chromosome:
• 9

From Peter Luykx, University of Miami, June 2005, his PL145

Phenotype: deficient in osmoregulation

This is the osm3 mutant in a nit1 background. (Please see CC-3701 for more information on this mutant.) This strain should be maintained on TAP medium supplemented with 0.06M sucrose or lactose. This strain has the wild-type allele at the NIT2 locus.

• Locus:
• NIT1
• Chromosome:
• 9

From Peter Luykx, University of Miami, June 2005, his PL44

Phenotype: deficient in osmoregulation

This appears to be the osm9 mutant (see CC-4010) from which the NIT1 insertion of the original strain has been removed by outcrossing. This strain should be maintained on TAP medium supplemented with 0.06M sucrose or lactose. This strain has the wild-type allele at the NIT2 locus.

• Locus:
• NIT1
• Chromosome:
• 9

From Peter Luykx, University of Miami, June 2005, his PL84.

Phenotype: deficient in osmoregulation

Please see CC-4019 for more information on this mutant. This strain should be maintained on TAP medium supplemented with 0.06M sucrose or lactose.