Maintenance and expression of heterologous genes in chloroplast ofChlamydomonas reinhardtii
Abstract
The chloroplast genome ofChlamydomonas reinhardtii has been transformed with a chimeric gene consisting of the chloroplastatpA promoter and the bacterial gene for aminoglycoside adenine transferase (aadA). TheatpA-aadA cassette has been placed within the chloroplast DNAEcoRI restriction enzyme fragment 14, or within the chloroplastBamH1 fragment 10. The chimeric constructs were introduced into the chloroplast by particle bombardment. Integration of the cassette into chloroplast DNA then occurred via homologous recombination of sequences flanking the cassette with their corresponding chloroplast sequences. We demonstrate that the chloroplastatpA promoter inatpA-aadA routinely recombines with its endogenous counterpart, resulting in heteroplasmic chloroplast DNA populations that may persist for many generations. The heterologous gene does not require a 3′ inverted repeat sequence for its expression. TheatpA-aadA gene copy number, which is dictated here by its position in the chloroplast genome, is proportional to the steady state level ofatpA-aadA mRNA. However, neither genomic position, gene copy number, or mRNA level have a significant effect on cellular resistance to spectinomycin, nor activity of theaadA gene productin vitro. These results suggest that, in the case ofaadA, the limiting step for expression of this gene is at the translational or post-translational level. TheatpA-aadA cassette should prove a useful model for future studies on the maintenance and expression of heterologous genes inC. reinhardtii chloroplasts.
Key words
Chlamydomonas reinhardtii transformation chloroplast aminoglycoside adenine transferasePreview
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References
- Bingham SE, Xu RH, Webber AN (1991) Transformation of chloroplasts with thepsaB gene encoding a polypeptide of the photosystem I reaction center. FEBS Lett. 292: 137–140Google Scholar
- Blowers AD, Bogorad L, Shark KB, Sanford JC (1989) Studies onChlamydomonas chloroplast transformation: foreign DNA can be stably maintained in the chromosome. Plant Cell 1: 123–132Google Scholar
- Blowers AD, Klein U, Ellmore GS, Bogorad L (1993) Functionalin vivo analysis of the 3′ flanking sequences of theChlamydomonas chloroplastrbcL andpsaB genes. Molec. gen. Genet. 238: 339–349Google Scholar
- Boynton JE, Gillham NW, Harris EH, Hosler JP, Johnson AM, Jones AR, Randolph-Anderson BL, Robertson D, Klein TM, Shark KB, Sanford JC (1988) Chloroplast transformation inChlamydomonas with high velocity microprojectiles. Science 240: 1534–1538Google Scholar
- Dron M, Rahire M, Rochaix J-D (1982) Sequence of the chloroplast DNA region ofChlamydomonas reinhardtii containing the gene of the large subunit of ribulose bisphosphate carboxylase and parts of its flanking genes. J. mol. Biol. 162: 775–793Google Scholar
- Goldschmidt-Clermont M (1991) Transgenic expression of aminoglycoside adenine transferase in the chloroplast: a selectable marker for site directed transformation ofChlamydomonas. Nuc. Acids Res. 19: 4083–4089Google Scholar
- Grant DM, Gillham NW, Boynton JE (1980) Inheritance of chloroplast DNA inChlamydomonas reinhardtii. Proc. natl. Acad. Sci. USA 77: 6067–6071Google Scholar
- Gruissem W, Tonkyn JC (1993) Control mechanisms of plastid gene expression. Crit. Rev. Plant Sci. 12: 19–65Google Scholar
- Harris EH (1989) The Chlamydomonas Sourcebook. Academic Press, New YorkGoogle Scholar
- Hosler JP, Wurtz EA, Harris EH, Gillham NW, Boynton JE (1989) Relationship between gene dosage and gene expression in the chloroplast ofChlamydomonas reinhardtii. Plant Physiol. 91: 648–655Google Scholar
- Kindle KL (1990) High frequency nuclear transformation ofChlamydomonas reinhardtii. Proc. natl. Acad. Sci. USA 87: 1228–1232Google Scholar
- Kindle KL, Richards KL, Stern DB (1991) Engineering the chloroplast genome: Techniques and capabilities for chloroplast transformation inChlamydomonas reinhardtii. Proc. natl. Acad. Sci. USA 88: 1721–1725Google Scholar
- Kindle KL, Schnell RA, Fernandez E, Lefebvre A (1989) Stable nuclear transformation ofChlamydomonas using the gene for nitrate reductase. J. Cell Biol. 109: 2589–2601Google Scholar
- Kuck U, Choquet Y, Schneider M, Dron M, Bennoun P (1987) Structural and transcription analysis of two homologous genes for the P700 chlorophylla-apoproteins inChlamydomonas reinhardtii: Evidence forin vivo transsplicing. EMBO J. 6: 2185–2195Google Scholar
- Newman SM, Boynton JE, Gillham NW, Randolph-Anderson BL, Johnson AM, Harris EH (1990) Transformation of chloroplast ribosomal RNA genes inChlamydomonas: Molecular and genetic characterization of integration events. Genetics 126: 875–888Google Scholar
- Newman SM, Gillham NW, Harris EH, Johnson AM, Boynton JE, (1992) Targeted disruption of chloroplast genes inChlamydomonas. Mol. gen. Genet. 230: 65–74Google Scholar
- Rochaix J-D, Mayfield S, Goldschmidt-Clermont M, Erickson J (1988) Molecular biology ofChlamydomonas. In Shaw CH (ed.), Plant Molecular Biology. IRL Press, OxfordGoogle Scholar
- Roffey RA, Golbeck JH, Hille CR, Sayre RT (1991) Photosynthetic electron transport in genetically altered photosystem II reaction centers of chloroplasts. Proc. natl. Acad. Sci. USA 88: 9122–9126Google Scholar
- Sakamoto W, Kindle KL, Stern DB (1993)In vivo analysis ofChlamydomonas chloroplastpetD gene expression using stable transformation of β-glucuronidase translational fusions. Proc. natl. Acad. Sci. 90: 497–501Google Scholar
- Salvador ML, Klein U, Bogorad L (1993) Light regulated and endogenous fluctuations of chloroplast transcript levels inChlamydomonas. Regulation by transcription and RNA degradation. The Plant J. 3: 213–219Google Scholar
- Sambrook J, Fritsch EF, Maniatis T (1989) Molecular Cloning. Cold Spring Harbor, New YorkGoogle Scholar
- Stern DB, Gruissem W (1987) Control of plastid gene expression: 3′ inverted repeats act as mRNA processing and stabilizing elements, but do not terminate transcription. Cell 51: 1145–1157Google Scholar
- Stern DB, Radwanski ER, Kindle KL (1991) A 3′ stem/loop structure of theChlamydomonas chloroplastatpB gene regulates mRNA accumulationin vivo. Plant Cell 3: 285–297Google Scholar
- Sueoka N (1960) Mitotic replication of deoxyribonucleic acid inChlamydomonas reinhardtii. Proc. natl. Acad. Sci. USA 76: 1353–1357Google Scholar
- Svab Z, Hajdukiewicz P, Maliga P (1990) Stable transformation of plastids in higher plants. Proc. natl. Acad. Sci. USA 87: 8526–8530Google Scholar
- Takahashi Y, Goldschmidt-Clermont M, Soen S-Y, Franzen LG, Rochaix J-D (1991) Directed chloroplast transformation inChlamydomonas reinhardtii: Insertional inactivation of thepsaC gene encoding the iron sulfur protein destabilizes photosystem 1. EMBO J. 10: 2033–2040Google Scholar
- Webber AN, Gibbs PB, Ward JW, Bingham SE (1993) Site-directed mutagenesis of the photosystem I reaction center in chloroplasts: the proline-cysteine motif. J. biol. Chem. 268: 12990–12995Google Scholar
- Woessner JP, Gillham NW, Boynton JE (1986) The sequence of the chloroplastatpB gene and its flanking regions inChlamydomonas reinhardtii. Gene 44: 17–28Google Scholar