Abstract
Southern hybridisation, polymerase chain reaction (PCR), and nucleotide sequence, data indicate that the 5s ribosomal RNA (rRNA) gene is linked to the main rRNA gene repeat in the nuclear genome of four cryptomonad algae (Rhinomonas pauca, Storeatula major, Komma caudata, and isolate cs 134). The 5s gene is apparently transcribed in the same direction as the large and small subunit rRNA genes. The intergenic spacer between the 5s gene and the large subunit rRNA gene exhibits length and sequence polymorphism among the different species. Cryptomonads contain two different eukaryotic genomes: the host nucleus and the nucleus of a eukaryotic endosymbiont. Mapping experiments with isolated chromosomes of the host and endosymbiont genomes showed that the intergenic spacer between the large subunit and the 5s rRNA gene, which was amplified from total DNA by PCR, was derived from the host nuclear genome.
Similar content being viewed by others
References
Appels R, Honeycutt RL (1986) rDNA: evolution over a billion years. In: Dutta SK (ed) DNA Systematics. CRC Press Inc., Boca Raton, Florida, pp 81–135
Belkhiri A, Buchko J, Klassen GR (1992) The 5s ribosomal RNA gene in Pythium species: two different genomic locations. Mol Biol Evol 9:1089–1102
Brown JW, Daniels CH, Reeve JN (1989) Gene structure and expression in archaebacteria. Crit Rev Microbiol 16:287–338
Douglas SE, Murphy CA, Spencer DA, Gray MW (1991) Molecular evidence that cryptomonad algae are evolutionary chimeras of two phylogenetically distant unicellular eukaryotes. Nature 350:148–151
Garrett RA, Dalgaard J, Larsen N, Kjems J, Manken AS (1991) Archeal rRNA operons. Trends Biochem Sci 16:22–26
Gerbi SA (1985) Evolution of ribosomal DNA. In: MacIntyre R (ed) Molecular evolutionary genetics. Plenum Press, New York, pp 419–517
Hansmann P, Eschbach S (1990) Isolation and preliminary characterisation of the nucleus and the nucleomorph of a cryptomonad, Pyrenomonas salina. Eur J Cell Biol 52:373–378
Hasegawa M, Hashimoto T, Adachi J, Iwabe N, Miyata T (1993) Early branchings in the evolution of eukaryotes: ancient divergence of entamoeba that lacks mitochondria revealed by protein sequence data. J Mol Evol 36:380–388
Hashimoto T, Nakamura Y, Nakamura F, Shirakura T, Adachi J, Goto N, Okamoto K, Hasegawa M (1994) Protein phylogeny gives a robust estimation for early divergences of eukaryotes-phylogenetic place of a mitochondria-lacking protozoan, Giardia lamlia. Mol Biol Evol 11:65–71
Higgins DG, Bleasby AJ, Fuchs R (1992) CLUSTAL V: improved software for multiple sequence alignment. CABIOS 8:189–191
Howlett BJ, Brownlee AG, Guest DI, Adcock GJ, McFadden GI (1992) The 5s ribosomal RNA gene is linked to the large and small subunit ribosomal RNA genes in the oomycetes, Phytophthora vignae, P. cinnamoni, P. megasperma f.sp. Glycinea and Saplroegnia ferax. Curr Genet 21:455–461
Jorgensen RA, Cuellar RE, Thompson WE, Kavanagh TA (1987) Structure and variation in the ribosomal RNA genes in pea. Characterisation of cloned repeat and chromosomal rDNA variants. Plant Mol Biol 8:3–12
Kumazaki T, Hori H, Osawa S (1982) The nucleotide sequence of 5s ribosomal RNA from the protozoan species Chilomonas paramecium belonging to the class Phytomastigophorea. FEBS Lett 149:281–284
Leipe DD, Gunderson JH, Nerad TA, Sogin ML (1993) Small subunit ribosomal RNA of Hexamita inflata and the quest for the first branch in the eukaryotic tree. Mol Biochem Parasitol 59:41–48
McFadden GI, Gilson PR, Douglas SE (1994) The photosynthetic endosymbiont in cryptomonad cells produces both chloroplast and cytoplasmic-type ribosomes. J Cell Sci 107:649–657
Maier UG, Hofmann CJB, Eschbach S, Wolters J, Igloi GL (1991) Demonstration of nucleomorph-encoded eukaryotic small subunit ribosomal RNA in crytopmonads. Mol Gen Genet 230:155–160
Rochaix JD, Mayfeild S, Goldschmidt-Clermont M, Erickson J (1988) Molecular biology of Chlamydomonas In: Shaw CH (ed) Plant molecular biology. IRL Press, Oxford, pp 253–275
Vossbrinck CR, Woese CR (1986) Ribosomal RNA sequence suggests microsporidia are extremely ancient eukaryotes. Nature 320:287–288
Author information
Authors and Affiliations
Additional information
Communicated by H. Kössel
Rights and permissions
About this article
Cite this article
Gilson, P.R., Adcock, G.J., Howlett, B.J. et al. Organisation and sequence analysis of nuclear-encoded 5s ribosomal RNA genes in cryptomonad algae. Curr Genet 27, 239–242 (1995). https://doi.org/10.1007/BF00326155
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00326155