1
|
Schlichting R, Bothe H. The Cyanelles (Organelles of a Low Evolutionary Scale) Possess a Phosphate-Translocator and a Glucose-Carrier inCyanophora paradoxa. ACTA ACUST UNITED AC 2014. [DOI: 10.1111/j.1438-8677.1993.tb00770.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
2
|
Abstract
Consistent with their postulated origin from endosymbiotic cyanobacteria, chloroplasts of plants and algae have ribosomes whose component RNAs and proteins are strikingly similar to those of eubacteria. Comparison of the secondary structures of 16S rRNAs of chloroplasts and bacteria has been particularly useful in identifying highly conserved regions likely to have essential functions. Comparative analysis of ribosomal protein sequences may likewise prove valuable in determining their roles in protein synthesis. This review is concerned primarily with the RNAs and proteins that constitute the chloroplast ribosome, the genes that encode these components, and their expression. It begins with an overview of chloroplast genome structure in land plants and algae and then presents a brief comparison of chloroplast and prokaryotic protein-synthesizing systems and a more detailed analysis of chloroplast rRNAs and ribosomal proteins. A description of the synthesis and assembly of chloroplast ribosomes follows. The review concludes with discussion of whether chloroplast protein synthesis is essential for cell survival.
Collapse
Affiliation(s)
- E H Harris
- DCMB Group, Department of Botany, Duke University, Durham, North Carolina 27708-1000
| | | | | |
Collapse
|
3
|
Boudreau E, Otis C, Turmel M. Conserved gene clusters in the highly rearranged chloroplast genomes of Chlamydomonas moewusii and Chlamydomonas reinhardtii. PLANT MOLECULAR BIOLOGY 1994; 24:585-602. [PMID: 8155879 DOI: 10.1007/bf00023556] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
We have extended to about 75 the number of genes mapped on the Chlamydomonas moewusii and Chlamydomonas reinhardtii chloroplast DNAs (cpDNAs) by partial sequencing of the very closely related C. eugametos and C. moewusii cpDNAs and by hybridizations with Chlamydomonas chloroplast gene-specific sequences. Only four of these genes (tscA and three reading frames) have not been identified in any other algal cpDNAs and thus may be specific to Chlamydomonas. Although the C. moewusii and C. reinhardtii cpDNAs differ by complex sequence rearrangements, 38 genes scattered throughout the genome define 12 conserved clusters of closely linked loci. Aside from the rRNA operon, four of these gene clusters share similarity to evolutionarily primitive operons found in other cpDNAs, representing in fact remnants of these operons. Our results thus indicate that most of the ancestral bacterial operons that characterize the chloroplast genome organization of land plants and early-diverging photosynthetic eukaryotes have been disrupted before the emergence of the polyphyletic genus Chlamydomonas. All gene rearrangements between the C. moewusii and C. reinhardtii cpDNAs, with the exception of those accounting for the relocations of atpA, psbI and rbcL, occurred within corresponding regions of the genome. One of these rearrangements seems to have led to disruption of the ancestral region containing rpl23, rpl2, rps19, rpl16, rpl14, rpl5, rps8 and the psaA exon 1. This gene cluster, which bears striking similarity to the Escherichia coli S10 and spc operons, spans a continuous DNA segment in C. reinhardtii, while it maps to two separate fragments in C. moewusii.
Collapse
Affiliation(s)
- E Boudreau
- Département de biochimie, Faculté des sciences et de génie, Université Laval, Québec, Canada
| | | | | |
Collapse
|
4
|
Fujiwara S, Kawachi M, Inouye I, Someya J. The gene for ribosomal protein L27 is located on the plastid rather than the nuclear genome of the chlorophyll c-containing alga Pleurochrysis carterae. PLANT MOLECULAR BIOLOGY 1994; 24:253-257. [PMID: 8111025 DOI: 10.1007/bf00040594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The gene for ribosomal protein L27 (rpl27) has not been found in plastid genomes. We report here that the rpl27 gene is located in the plastid genome of the prymnesiophyte Pleurochrysis carterae. The deduced amino acid sequence showed 59% identity with E. coli L27. 1.0 kb transcript of the gene was detected by Northern blot analysis. Nucleotide sequence analysis of PCR products suggested that rpl27 is widespread in the genomes of Prymesiophyta and Rhodophyta. In all species of Prymnesiophyta examined in this study, the gene is located at the 3' downstream region of Rubisco operon.
Collapse
Affiliation(s)
- S Fujiwara
- National Institute of Bioscience and Human Technology, Agency of Industrial Science and Technology, Ibaraki, Japan
| | | | | | | |
Collapse
|
5
|
Löffelhardt W, Bohnert HJ. Structure and function of the cyanelle genome. INTERNATIONAL REVIEW OF CYTOLOGY 1994; 151:29-65. [PMID: 7516928 DOI: 10.1016/s0074-7696(08)62630-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- W Löffelhardt
- Institut für Biochemie und Molekulare Zellbiologie, Universität Wien, Austria
| | | |
Collapse
|
6
|
Reith M, Munholland J. The ribosomal RNA repeats are non-identical and directly oriented in the chloroplast genome of the red alga Porphyra purpurea. Curr Genet 1993; 24:443-50. [PMID: 8299161 DOI: 10.1007/bf00351855] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A detailed restriction map of the chloroplast genome of the red alga Porphyra purpurea has been constructed. Southern hybridization experiments with cloned or gel-purified restriction fragments and PCR products indicate that the P. purpurea chloroplast genome is approximately 188 kb in size. This circular molecule contains two rRNA-encoding repeats (approximately 4.9 kb) that separate the genome into single-copy regions of 34 kb and 144 kb. Interestingly, these repeats are arranged in a direct orientation. In addition, DNA sequencing of the ends of both repeats revealed that the two rRNA repeats are not identical. No intramolecular recombination between the repeats can be detected. We discuss the possibility that the chloroplast genome of P. purpurea is organized like that of the ancestral chloroplast.
Collapse
Affiliation(s)
- M Reith
- National Research Council of Canada, Institute for Marine Biosciences, Halifax, Nova Scotia
| | | |
Collapse
|
7
|
SecY, an integral subunit of the bacterial preprotein translocase, is encoded by a plastid genome. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)53205-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
|
8
|
Li LA, Gibson JL, Tabita FR. The Rubisco activase (rca) gene is located downstream from rbcS in Anabaena sp. strain CA and is detected in other Anabaena/Nostoc strains. PLANT MOLECULAR BIOLOGY 1993; 21:753-764. [PMID: 8467074 DOI: 10.1007/bf00027109] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A gene encoding ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) activase (rca) was found downstream from the rbcLrbcS operon in the heterocystous cyanobacterium Anabaena sp. strain CA. Two unknown open reading frames were shown to be located between rbcS and rca in strain CA and all the genes, rbcLrbcS, ORF1, ORF2, and rca were in the same transcriptional orientation. The deduced amino acid sequence of the Anabaena Rubisco activase showed both similarities and differences to the plant enzyme with considerable differences at the carboxy and amino termini. Proposed ATP-binding sites were conserved in the cyanobacterial protein. Recombinant cyanobacterial Rubisco activase, however, reacted with antisera to spinach Rubisco activase. Hybridization studies, using the Anabaena sp. strain CA rca gene as a heterologous probe, detected homologous sequences in heterocystous Anabaena/Nostoc strains but not in unicellular or nonheterocystous filamentous cyanobacteria, suggestive of a close evolutionary relationship of chloroplasts and heterocystous cyanobacteria.
Collapse
Affiliation(s)
- L A Li
- Department of Microbiology, Ohio State University, Columbus 43210-1192
| | | | | |
Collapse
|
9
|
Reith M, Munholland J. Two amino-acid biosynthetic genes are encoded on the plastid genome of the red alga Porphyra umbilicalis. Curr Genet 1993; 23:59-65. [PMID: 8381336 DOI: 10.1007/bf00336751] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
To isolate the gene encoding the amino-acid biosynthetic enzyme acetolactate synthase (ALS) from the red alga Porphyra umbilicalis, PCR experiments were carried out using P. umbilicalis DNA as the template and degenerate oligonucleotides representing conserved regions of ALS amino-acid sequences. Interestingly, the PCR product (0.9 kb) hybridized exclusively to the plastid DNA of this red alga. DNA sequencing of two contiguous EcoRI plastid DNA clones revealed a 590 amino-acid open reading frame with 55 to 61% identity to cyanobacterial ALS sequences. A second gene (argB) encoding another amino-acid biosynthetic enzyme, N-acetylglutamate kinase, was identified upstream of, and on the opposite strand to the gene encoding ALS (ilvB). This is the first molecular characterization of a gene for an arginine biosynthetic enzyme from any plant. In addition, two tRNA genes, trnT(GGU) and trnY(GUA), were detected downstream from ilvB while four tRNA genes, trnfM(CAU), trnA(GGC), trnA(GGC), trnS(-GCU) and trnD(GUC), were found downstream from argB. trnA(GGC) is not found in the chloroplast genomes of land plants.
Collapse
Affiliation(s)
- M Reith
- National Research Council of Canada, Institute for Marine Biosciences, Halifax, Nova Scotia
| | | |
Collapse
|
10
|
Affiliation(s)
- M W Gray
- Department of Biochemistry, Dalhousie University, Halifax, Nova Scotia, Canada
| |
Collapse
|
11
|
Comparison of Chloroplast and Mitochondrial Genome Evolution in Plants. PLANT GENE RESEARCH 1992. [DOI: 10.1007/978-3-7091-9138-5_3] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
12
|
Giese K, Subramanian AR. Expression and functional assembly into bacterial ribosomes of a nuclear-encoded chloroplast ribosomal protein with a long NH2-terminal extension. FEBS Lett 1991; 288:72-6. [PMID: 1879566 DOI: 10.1016/0014-5793(91)81005-s] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Chloroplast ribosomal protein L13 is encoded in the plant nucleus and is considerably larger than its eubacterial homologue by having NH2- and COOH-terminal extensions with no homology to any known sequences (Phua et al., J Biol. Chem. 264, 1968-1971, 1989). We made two gene constructs of L13 cDNA using the polymerase chain reaction (PCR) and expressed them in Escherichia coli. Analysis of the ribosomes and polysomes from these cells, using an antiserum specific to chloroplast L13, shows that the expressed proteins are incorporated, in the presence of the homologous E. coli L13, into functional ribosomes which participate in protein synthesis (i.e. polysomes). Evidence is obtained that the large NH2-terminal extension probably lies on the surface of these 'mosaic ribosomes.' This first report of the assembly into E. coli ribosomes of nuclear-coded chloroplast ribosomal protein with terminal extensions thus suggest an extraordinary conservation in the function of eubacterial type ribosomal proteins, despite the many changes in protein structure during their evolution inside a eukaryotic system.
Collapse
Affiliation(s)
- K Giese
- Max-Planck-Institut für Molekulare Genetik, Abteilung Wittmann, Berlin, Germany
| | | |
Collapse
|
13
|
Michalowski C, Löffelhardt W, Bohnert H. An ORF323 with homology to crtE, specifying prephytoene pyrophosphate dehydrogenase, is encoded by cyanelle DNA in the eukaryotic alga Cyanophora paradoxa. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)99037-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
14
|
Jahn O, Hartmann RK, Boeckh T, Erdmann VA. Comparative analysis of ribosomal protein L5 sequences from bacteria of the genus Thermus. Biochimie 1991; 73:669-78. [PMID: 1764514 DOI: 10.1016/0300-9084(91)90046-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The genes for the ribosomal 5S rRNA binding protein L5 have been cloned from three extremely thermophilic eubacteria, Thermus flavus, Thermus thermophilus HB8 and Thermus aquaticus (Jahn et al, submitted). Genes for protein L5 from the three Thermus strains display 95% G/C in third positions of codons. Amino acid sequences deduced from the DNA sequence were shown to be identical for T flavus and T thermophilus, although the corresponding DNA sequences differed by two T to C transitions in the T thermophilus gene. Protein L5 sequences from T flavus and T thermophilus are 95% homologous to L5 from T aquaticus and 56.5% homologous to the corresponding E coli sequence. The lowest degrees of homology were found between the T flavus/T thermophilus L5 proteins and those of yeast L16 (27.5%), Halobacterium marismortui (34.0%) and Methanococcus vannielii (36.6%). From sequence comparison it becomes clear that thermostability of Thermus L5 proteins is achieved by an increase in hydrophobic interactions and/or by restriction of steric flexibility due to the introduction of amino acids with branched aliphatic side chains such as leucine. Alignment of the nine protein sequences equivalent to Thermus L5 proteins led to identification of a conserved internal segment, rich in acidic amino acids, which shows homology to subsequences of E coli L18 and L25. The occurrence of conserved sequence elements in 5S rRNA binding proteins and ribosomal proteins in general is discussed in terms of evolution and function.
Collapse
Affiliation(s)
- O Jahn
- Institut für Biochemie, Freie Universität Berlin, Germany
| | | | | | | |
Collapse
|
15
|
Douglas SE. Unusual organization of a ribosomal protein operon in the plastid genome of Cryptomonas phi: evolutionary considerations. Curr Genet 1991; 19:289-94. [PMID: 1868578 DOI: 10.1007/bf00355057] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The region of the plastid genome containing the genes for ribosomal proteins S12 and S7 and the elongation factor Tu (corresponding to three of the four str operon genes of Escherichia coli) was investigated in the unicellular marine alga Cryptomonas. Sequence analysis shows the gene organization to be rps12-60 bp spacer-rps7-68 bp spacer-tufA. No introns are present in any of the genes. Comparisons of the deduced amino acid sequence of these genes with homologues from other organisms show rps12 to be very highly conserved, except at the amino terminus, and rps7 and tufA to be less well-conserved. Transcript analysis suggests that these genes are co-transcribed along with several up and/or down-stream genes. The evolutionary significance of this unique gene organization is discussed.
Collapse
Affiliation(s)
- S E Douglas
- Atlantic Research Laboratory, National Research Council, Halifax, Nova Scotia, Canada
| |
Collapse
|
16
|
Capuano V, Braux AS, Tandeau de Marsac N, Houmard J. The “anchor polypeptide” of cyanobacterial phycobilisomes. Molecular characterization of the Synechococcus sp. PCC 6301 apce gene. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(20)89636-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
17
|
Neumann-Spallart C, Jakowitsch J, Kraus M, Brandtner M, Bohnert HJ, Löffelhardt W. rps10, unreported for plastid DNAs, is located on the cyanelle genome of Cyanophora paradoxa and is cotranscribed with the str operon genes. Curr Genet 1991; 19:313-5. [PMID: 1907893 DOI: 10.1007/bf00355061] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
rps10, encoding the plastid ribosomal protein S10, is a nuclear gene in higher plants and green algae, and is missing from the large ribosomal protein gene cluster of chlorophyll b-type plastids that contains components of the prokaryotic S10, spc and alpha operons. The cyanelle genome of Cyanophora paradoxa is shown to harbor rps10 as another specific feature of its organization. However, this novel plastid gene is not contiguous with the genes of the "S10" operon, but is adjacent to, and cotranscribed with, the str operon, a trait also found in archaebacteria.
Collapse
|
18
|
Bryant DA, Schluchter WM, Stirewalt VL. Ferredoxin and ribosomal protein S10 are encoded on the cyanelle genome of Cyanophora paradoxa. Gene X 1991; 98:169-75. [PMID: 1901820 DOI: 10.1016/0378-1119(91)90170-g] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The petF and rsp10 genes of the cyanellar genome of the taxonomically ambiguous flagellate Cyanophora paradoxa have been cloned, mapped, and sequenced. In higher plants these genes are not encoded in the chloroplast DNA, but are encoded in the nucleus. The C. paradoxa petF gene predicts a protein of 99 amino acids (aa) which is more similar to type-I ferredoxins of diverse cyanobacteria than to those of green algae, dinoflagellates, and higher plants. The rsp10 gene (rspJ) predicts a protein of 105 aa which is about 50% identical and 71% homologous to the proteins of Escherichia coli and Mycoplasma capricolum. The results are discussed within the context of the endosymbiotic origins of chloroplasts from cyanobacteria.
Collapse
Affiliation(s)
- D A Bryant
- Department of Molecular and Cell Biology, Pennsylvania State University, University Park 16802
| | | | | |
Collapse
|
19
|
Michalowski CB, Pfanzagl B, Löffelhardt W, Bohnert HJ. The cyanelle S10 spc ribosomal protein gene operon from Cyanophora paradoxa. MOLECULAR & GENERAL GENETICS : MGG 1990; 224:222-31. [PMID: 2126059 DOI: 10.1007/bf00271555] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In Cyanophora paradoxa photosynthetic organelles termed cyanelles perform the functions of chloroplasts in higher plants, while the structural and biochemical characteristics of the cyanelle are essentially cyanobacterial. Our interest in studying the evolutionary relationship between cyanelles and chloroplasts led us to focus on cyanelle-encoded genes of the translational apparatus, specifically genes equivalent to those of the bacterial S10 and spc operons. The structure of a large ribosomal protein gene cluster from cyanelle DNA was characterized and compared with that from plastids and bacteria. Sequences of the following cyanelle genes encompassing 4.8 kb are reported here: 5'-rpl22-rps3-rpl16-rps17-rpl14-rpl5-rps8-rpl6-rpl18- rps5-3'. Cyanelles contain five more ribosomal protein genes than do higher plant chloroplasts and four more genes than Euglena gracilis plastids in the S10/spc region of this gene cluster. The gene encoding rpl36 is absent, in contrast to the case in other plastid DNAs. These genes, including the previously characterized genes rpl3, rpl2 and rps19, are transcribed as a primary transcript of approximately 7500 nucleotides. The occurrence of transcripts smaller than this presumptive primary transcript suggests that it is processed into defined segments. Transcription terminates 3' of rps5 where a 40 bp hairpin with one mismatch (-42.2 kcal) may be folded. Immediately downstream of rps5 an open reading frame, ORF492, is contained on a separate transcript. A comparison of gene content, operon structure and deduced amino acid sequence of the genes in the S10 and spc operons from different organisms supports the notion that cyanelles are intermediary between known plastids and cyanobacteria.
Collapse
Affiliation(s)
- C B Michalowski
- Department of Biochemistry, University of Arizona, Tucson 85721
| | | | | | | |
Collapse
|
20
|
Valentin K, Zetsche K. Nucleotide sequence of the gene for the large subunit of Rubisco from Cyanophora paradoxa--phylogenetic implications. Curr Genet 1990; 18:199-202. [PMID: 2123417 DOI: 10.1007/bf00318380] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The gene (rbcL) for the large subunit (LSU) of Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) from Cyanophora paradoxa was cloned and the nucleotide sequence determined. Sequence homologies to rbcL genes from other sources clearly indicated a close phylogenetic relationship between the photosynthetic organelles of Cyanophora (cyanelles), green chloroplasts and cyanobacteria. Our data support the hypothesis that the cyanelles of Cyanophora may represent a closely related, but independent, side line to chloroplast evolution. Cyanelles and rhodoplasts or phaeoplasts seem not to be related.
Collapse
Affiliation(s)
- K Valentin
- Institut für Pflanzenphysiologie, Justus-Liebig-Universität, Giessen, Federal Republic of Germany
| | | |
Collapse
|
21
|
Neumann-Spallart C, Brandtner M, Kraus M, Jakowitsch J, Bayer MG, Maier TL, Schenk HE, Löffelhardt W. The petFI gene encoding ferredoxin I is located close to the str operon on the cyanelle genome of Cyanophora paradoxa. FEBS Lett 1990; 268:55-8. [PMID: 2116981 DOI: 10.1016/0014-5793(90)80971-k] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The petFI gene encoding ferredoxin I was localized in the large single copy region of cyanelle DNA by heterologous hybridization. Sequence analysis revealed an ORF of 99 amino acids (including the N-terminal processed methionine) at a position 477 bp from the 3' end of tufA but on the opposite strand. The 25 amino-terminal residues well corresponded to partial sequences obtained with purified cyanelle ferredoxin. The assignment of yet another gene that is not found on the genomes of chlorophyll b-type plastids to cyanelle DNA again corroborates the special position of cyanelles serving as a model for plastid evolution from endocytobiotic cyanobacteria.
Collapse
|