Abstract
Comparison of two group I intron sequences in the nucleolar genome of the myxomycete Physarum flavicomum to their homologs in the closely related Physarum polycephalum revealed insertion-like elements. One of the insertion-like elements consists of two repetitive sequence motifs of 11 and 101 bp in five and three copies, respectively. The smaller motif, which flanks the larger, resembles a target duplication and indicates a relationship to transposons or retroelements. The insertion-like elements are found in the peripheral loops of the RNA structure; the positions occupied by the ORFs of mobile nucleolar group I introns. The P. flavicomum introns are 1184 and 637 bp in size, located in the large subunit ribosomal RNA gene, and can be folded into group I intron structures at the RNA level. However, the intron 2s from both P. flavicomum and P. polycephalum contain an unusual core region that lacks the P8 segment. None of the introns are able to self-splice in vitro. Southern analysis of different isolates indicates that the introns are not optional in myxomycetes.
Full text
PDF






Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Aimi T., Yamada T., Murooka Y. A group-I self-splicing intron in the nuclear small subunit rRNA-encoding gene of the green alga, Chlorella ellipsoidea C-87. Gene. 1994 Feb 11;139(1):65–71. doi: 10.1016/0378-1119(94)90524-x. [DOI] [PubMed] [Google Scholar]
- Aimi T., Yamada T., Murooka Y. Group I self-splicing introns in both large and small subunit rRNA genes of Chlorella. Nucleic Acids Symp Ser. 1993;(29):159–160. [PubMed] [Google Scholar]
- Belfort M. Self-splicing introns in prokaryotes: migrant fossils? Cell. 1991 Jan 11;64(1):9–11. doi: 10.1016/0092-8674(91)90201-9. [DOI] [PubMed] [Google Scholar]
- Cech T. R. Self-splicing of group I introns. Annu Rev Biochem. 1990;59:543–568. doi: 10.1146/annurev.bi.59.070190.002551. [DOI] [PubMed] [Google Scholar]
- Cech T. R., Zaug A. J., Grabowski P. J. In vitro splicing of the ribosomal RNA precursor of Tetrahymena: involvement of a guanosine nucleotide in the excision of the intervening sequence. Cell. 1981 Dec;27(3 Pt 2):487–496. doi: 10.1016/0092-8674(81)90390-1. [DOI] [PubMed] [Google Scholar]
- De Jonckheere J. F. A group I intron in the SSUrDNA of some Naegleria spp. demonstrated by polymerase chain reaction amplification. J Eukaryot Microbiol. 1993 Mar-Apr;40(2):179–187. doi: 10.1111/j.1550-7408.1993.tb04901.x. [DOI] [PubMed] [Google Scholar]
- De Wachter R., Neefs J. M., Goris A., Van de Peer Y. The gene coding for small ribosomal subunit RNA in the basidiomycete Ustilago maydis contains a group I intron. Nucleic Acids Res. 1992 Mar 25;20(6):1251–1257. doi: 10.1093/nar/20.6.1251. [DOI] [PMC free article] [PubMed] [Google Scholar]
- DePriest P. T., Been M. D. Numerous group I introns with variable distributions in the ribosomal DNA of a lichen fungus. J Mol Biol. 1992 Nov 20;228(2):315–321. doi: 10.1016/0022-2836(92)90819-6. [DOI] [PubMed] [Google Scholar]
- Dujon B. Group I introns as mobile genetic elements: facts and mechanistic speculations--a review. Gene. 1989 Oct 15;82(1):91–114. doi: 10.1016/0378-1119(89)90034-6. [DOI] [PubMed] [Google Scholar]
- Dávila-Aponte J. A., Huss V. A., Sogin M. L., Cech T. R. A self-splicing group I intron in the nuclear pre-rRNA of the green alga, Ankistrodesmus stipitatus. Nucleic Acids Res. 1991 Aug 25;19(16):4429–4436. doi: 10.1093/nar/19.16.4429. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gast R. J., Fuerst P. A., Byers T. J. Discovery of group I introns in the nuclear small subunit ribosomal RNA genes of Acanthamoeba. Nucleic Acids Res. 1994 Feb 25;22(4):592–596. doi: 10.1093/nar/22.4.592. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hinkle G., Leipe D. D., Nerad T. A., Sogin M. L. The unusually long small subunit ribosomal RNA of Phreatamoeba balamuthi. Nucleic Acids Res. 1994 Feb 11;22(3):465–469. doi: 10.1093/nar/22.3.465. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hofmann J., Schumann G., Borschet G., Gösseringer R., Bach M., Bertling W. M., Marschalek R., Dingermann T. Transfer RNA genes from Dictyostelium discoideum are frequently associated with repetitive elements and contain consensus boxes in their 5' and 3'-flanking regions. J Mol Biol. 1991 Dec 5;222(3):537–552. doi: 10.1016/0022-2836(91)90495-r. [DOI] [PubMed] [Google Scholar]
- Johansen S., Embley T. M., Willassen N. P. A family of nuclear homing endonucleases. Nucleic Acids Res. 1993 Sep 11;21(18):4405–4405. doi: 10.1093/nar/21.18.4405. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Johansen S., Johansen T., Haugli F. Extrachromosomal ribosomal DNA of Didymium iridis: sequence analysis of the large subunit ribosomal RNA gene and sub-telomeric region. Curr Genet. 1992 Oct;22(4):305–312. doi: 10.1007/BF00317926. [DOI] [PubMed] [Google Scholar]
- Johansen S., Johansen T., Haugli F. Structure and evolution of myxomycete nuclear group I introns: a model for horizontal transfer by intron homing. Curr Genet. 1992 Oct;22(4):297–304. doi: 10.1007/BF00317925. [DOI] [PubMed] [Google Scholar]
- Johansen S. Strain-dependent sequence heterogeneity in the nuclear group I introns and large subunit ribosomal RNA in Physarum polycephalum. DNA Seq. 1991;2(3):193–196. doi: 10.3109/10425179109039689. [DOI] [PubMed] [Google Scholar]
- Johansen S., Vogt V. M. An intron in the nuclear ribosomal DNA of Didymium iridis codes for a group I ribozyme and a novel ribozyme that cooperate in self-splicing. Cell. 1994 Feb 25;76(4):725–734. doi: 10.1016/0092-8674(94)90511-8. [DOI] [PubMed] [Google Scholar]
- Lambowitz A. M., Belfort M. Introns as mobile genetic elements. Annu Rev Biochem. 1993;62:587–622. doi: 10.1146/annurev.bi.62.070193.003103. [DOI] [PubMed] [Google Scholar]
- Levinson G., Gutman G. A. Slipped-strand mispairing: a major mechanism for DNA sequence evolution. Mol Biol Evol. 1987 May;4(3):203–221. doi: 10.1093/oxfordjournals.molbev.a040442. [DOI] [PubMed] [Google Scholar]
- Lin H., Niu M. T., Yoganathan T., Buck G. A. Characterization of the rRNA-encoding genes and transcripts, and a group-I self-splicing intron in Pneumocystis carinii. Gene. 1992 Oct 1;119(2):163–173. doi: 10.1016/0378-1119(92)90268-t. [DOI] [PubMed] [Google Scholar]
- Liu Y., Rocourt M., Pan S., Liu C., Leibowitz M. J. Sequence and variability of the 5.8S and 26S rRNA genes of Pneumocystis carinii. Nucleic Acids Res. 1992 Jul 25;20(14):3763–3772. doi: 10.1093/nar/20.14.3763. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mercure S., Montplaisir S., Lemay G. Correlation between the presence of a self-splicing intron in the 25S rDNA of C.albicans and strains susceptibility to 5-fluorocytosine. Nucleic Acids Res. 1993 Dec 25;21(25):6020–6027. doi: 10.1093/nar/21.25.6020. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Michel F., Westhof E. Modelling of the three-dimensional architecture of group I catalytic introns based on comparative sequence analysis. J Mol Biol. 1990 Dec 5;216(3):585–610. doi: 10.1016/0022-2836(90)90386-Z. [DOI] [PubMed] [Google Scholar]
- Mota E. M., Collins R. A. Independent evolution of structural and coding regions in a Neurospora mitochondrial intron. Nature. 1988 Apr 14;332(6165):654–656. doi: 10.1038/332654a0. [DOI] [PubMed] [Google Scholar]
- Muscarella D. E., Vogt V. M. A mobile group I intron in the nuclear rDNA of Physarum polycephalum. Cell. 1989 Feb 10;56(3):443–454. doi: 10.1016/0092-8674(89)90247-x. [DOI] [PubMed] [Google Scholar]
- Nielsen H., Engberg J. Sequence comparison of the rDNA introns from six different species of Tetrahymena. Nucleic Acids Res. 1985 Oct 25;13(20):7445–7455. doi: 10.1093/nar/13.20.7445. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Oliveira M. C., Ragan M. A. Variant forms of a group I intron in nuclear small-subunit rRNA genes of the marine red alga Porphyra spiralis var. amplifolia. Mol Biol Evol. 1994 Mar;11(2):195–207. doi: 10.1093/oxfordjournals.molbev.a040102. [DOI] [PubMed] [Google Scholar]
- Otsuka T., Nomiyama H., Yoshida H., Kukita T., Kuhara S., Sakaki Y. Complete nucleotide sequence of the 26S rRNA gene of Physarum polycephalum: its significance in gene evolution. Proc Natl Acad Sci U S A. 1983 Jun;80(11):3163–3167. doi: 10.1073/pnas.80.11.3163. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Perler F. B., Davis E. O., Dean G. E., Gimble F. S., Jack W. E., Neff N., Noren C. J., Thorner J., Belfort M. Protein splicing elements: inteins and exteins--a definition of terms and recommended nomenclature. Nucleic Acids Res. 1994 Apr 11;22(7):1125–1127. doi: 10.1093/nar/22.7.1125. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ragan M. A., Bird C. J., Rice E. L., Singh R. K. The nuclear 18S ribosomal RNA gene of the red alga Hildenbrandia rubra contains a group I intron. Nucleic Acids Res. 1993 Aug 11;21(16):3898–3898. doi: 10.1093/nar/21.16.3898. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Raué H. A., Klootwijk J., Musters W. Evolutionary conservation of structure and function of high molecular weight ribosomal RNA. Prog Biophys Mol Biol. 1988;51(2):77–129. doi: 10.1016/0079-6107(88)90011-9. [DOI] [PubMed] [Google Scholar]
- Rogers S. O., Yan Z. H., Shinohara M., LoBuglio K. F., Wang C. J. Messenger RNA intron in the nuclear 18s ribosomal RNA gene of deuteromycetes. Curr Genet. 1993;23(4):338–342. doi: 10.1007/BF00310896. [DOI] [PubMed] [Google Scholar]
- Ruoff B., Johansen S., Vogt V. M. Characterization of the self-splicing products of a mobile intron from the nuclear rDNA of Physarum polycephalum. Nucleic Acids Res. 1992 Nov 25;20(22):5899–5906. doi: 10.1093/nar/20.22.5899. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Van Oppen M. J., Olsen J. L., Stam W. T. Evidence for independent acquisition of group I introns in green algae. Mol Biol Evol. 1993 Nov;10(6):1317–1326. doi: 10.1093/oxfordjournals.molbev.a040078. [DOI] [PubMed] [Google Scholar]
- Wilcox L. W., Lewis L. A., Fuerst P. A., Floyd G. L. Group I introns within the nuclear-encoded small-subunit rRNA gene of three green algae. Mol Biol Evol. 1992 Nov;9(6):1103–1118. doi: 10.1093/oxfordjournals.molbev.a040781. [DOI] [PubMed] [Google Scholar]
- Yamada T., Tamura K., Aimi T., Songsri P. Self-splicing group I introns in eukaryotic viruses. Nucleic Acids Res. 1994 Jul 11;22(13):2532–2537. doi: 10.1093/nar/22.13.2532. [DOI] [PMC free article] [PubMed] [Google Scholar]