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Multiple ribosomal gene sites revealed by in situ hybridization of Xenopus rDNA to Tritums lampbrush chromosomes

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Abstract

A variety of 3H-labelled ribosomal gene probes were hybridized in situ to the nascent transcripts of lampbrush chromosomes from the crested newt, Tritums cristatus carnifex. The probes were from Xenopus laevis and included rDNA isolated by CsCl gradient centrifugation, recombinant plasmids and purified restriction fragments of rDNA. All the probes gave essentially the same result. About 10–15 loop pairs were distinctly labelled in each preparation, almost all of them located on the heteromorphic arms (HTAs) of chromosome 1. Ribosomal gene probes were also hybridized in situ to the DNA of denatured mitotic chromosomes from some of the individuals used to provide lampbrush preparations. Minor, scattered sites of hybridization were found in the HTAs, but the main clusters of ribosomal genes were found on chromosomes 6 and/or 9, in agreement with previous determinations of nucleolus organizer position in this species. However, the nucleolus organizers were not sites of labelled loops in lampbrush transcript hybridizations. — We have incubated isolated lampbrush-stage nuclei in media containing α-amanitin and labelled RNA precursors. Although extrachromosomal nucleolar genes incorporated label, supposedly due to transcription by RNA polymerase I, no lampbrush loops were labelled. — It appears that in T. c. carnifex there are ribosomal gene sequences at the main nucleolus organizers and at a number of sites scattered along the HTAs. The ribosomal genes at the nucleolus organizers are not extended in the form of actively transcribing loops unlike the ribosomal sequences on the HTAs, which are heavily labelled in transcript hybridization. The ribosomal sequences on the HTAs appear not to be transcribed by the same RNA polymerase that transcribes the ribosomal genes of extrachromosomal nucleoli.

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References

  • Barsacchi-Pilone, G., Nardi, I., Batistoni, R., Andronico, F., Beccari, E., Chromosome location of 28S, 18S and 5S ribosomal RNA genes in Triturus (Amphibia, Urodela). Boll. Zool. 41, 456 (1974)

    Google Scholar 

  • Bird, A.P., Southern, E.M., Use of restriction enzymes to study eukaryotic DNA methylation: I. The methylation pattern in ribosomal DNA from Xenopus laevis. J. molec. Biol. 118, 27–47 (1978)

    Google Scholar 

  • Boseley, P.G., Tuyns, A., Birnstiel, M.L., Mapping of the Xenopus laevis 5.8S rDNA by restriction and DNA sequencing. Nucleic Acids Res. 5, 1121–1137 (1978)

    Google Scholar 

  • Callan, H.G., Chromosomes and nucleoli of the axolotl, Ambystoma mexicanum. J. Cell. Sci. 1, 85–108 (1966)

    Google Scholar 

  • Callan, H.G., Lloyd, L., Lampbrush chromosomes of crested newts Triturus cristatus (Laurenti), Phil. Trans. roy. Soc. Lond. B 243, 134–219 (1960)

    Google Scholar 

  • Callan, H.G., Lloyd, L., Working maps of the lampbrush chromosomes of Amphibia. In: Handbook of genetics, 4 (R.C. King, ed.), pp. 57–77. New York: Plenum Publishing Corp. 1975

  • Clewell, D.B., Helsinski, D.R., Supercoiled circular DNA-protein complex in Escherichia coli: purification and induced conversion to an open circular DNA form. Proc. natl. Acad. Sci. (Wash.) 62, 1159–1166 (1969)

    Google Scholar 

  • Colman, A., Byers, M.J., Primrose, S.B., Lyons, A. Purification of plasmid DNAs by hydroxyapatite chromatography. Europ. J. Biochem. 91, 303–310 (1978)

    Google Scholar 

  • Dawid, I.B., Brown, D.D., Reeder, R.H., Composition and structure of chromosomal and amplified ribosomal DNAs of Xenopus laevis. J. molec. Biol. 51, 341–360 (1970)

    Google Scholar 

  • Franke, W.W., Scheer, U., Spring, H., Trendelenburg, M.F., Krohne, G., Morphology of transcriptional units of rDNA. Evidence for transcription in apparent spacer intercepts and cleavages in the elongating nascent RNA. Exp. Cell Res. 100, 233–244 (1976)

    Google Scholar 

  • Gall, J.G., Pardue, M.L., Nucleic acid hybridization in cytological preparations. In: Methods in enzymology, 21 (L. Grossman and K. Moldave, eds.), pp. 470–480. New York: Academic Press 1971

  • Gillespie, D., Speigelman, S., A quantitive assay for DNA-RNA hybrids with DNA immobilized on a membrane. J. molec. Biol. 12, 829–842 (1965)

    Google Scholar 

  • Hennen, S., Mizuno, S., Macgregor, H.C., In situ hybridization of ribosomal DNA labelled with 125iodine to metaphase and lampbrush chromosomes from newts. Chromosoma (Berl.) 50, 349–369 (1975)

    Google Scholar 

  • Hutchison, N., Pardue, M.L., The mitotic chromosomes of Notophthalmus (=Triturus) viridescens: localization of c-banding regions and DNA sequences complementary to 18S, 28S and 5S ribosomal RNA. Chromosoma (Berl.) 53, 51–69 (1975)

    Google Scholar 

  • Kezer, J., Macgregor, H.C., The nucleolar organizer of Plethodon cinereus cinereus (Green) II. The lampbrush nucleolar organizer. Chromosoma (Berl.) 42, 427–444 (1973)

    Google Scholar 

  • Kezer, J., Sessions, S.K., Chromosome variation in the plethodontid salamander, Aneides ferreus. Chromosoma (Berl.) 71, 65–80 (1979)

    Google Scholar 

  • Macgregor, H.C., Morphological variability and its physiological origin in oocyte nuclei of the crested newt. Quart. J. microsc. Sci. 104, 351–368 (1963)

    Google Scholar 

  • Macgregor, H.C., In situ hybridization of highly repetitive DNA to chromosomes of Triturus cristatus. Chromosoma (Berl.) 71, 57–64 (1979)

    Google Scholar 

  • Macgregor, H.C., Andrews, C., The arrangement and transcirption of “middle repetitive” DNA sequences on lampbrush chromosomes of Triturus. Chromosoma (Berl.) 63 109–126 (1977)

    Google Scholar 

  • Macgregor, H.C., Mizuno, S., In situ hybridization of “nick-translated” 3H-ribosomal DNA to chromosomes from salamanders. Chromosoma (Berl.) 54, 15–25 (1976)

    Google Scholar 

  • Macgregor, H.C., Sherwood, S., The nucleolus organizers of Plethodon and Aneides located by in situ nucleic acid hybridization with Xenopus 3H-ribosomal RNA. Chromosoma (Berl.) 72, 271–280 (1979)

    Google Scholar 

  • Macgregor, H.C., Vlad, M., Barnett, L., An investigation of some problems concerning nucleolus organizers in salamanders. Chromosoma (Berl.) 59, 283–299 (1977)

    Google Scholar 

  • Mancino, G., Nardi, I., Ragghianti, M., Lampbrush chromosomes from semialbino crested newts, Triturus cristatus carnifex (Laurenti). Experientia (Basel.) 28, 856–860 (1972)

    Google Scholar 

  • Mancino, G., Ragghianti, M., Innocenti, S.B., I cariotipi di Trituras marmoratus e T. cristatus studiati con il “C-staining” method. Atti. Accad. naz. Lincei Rc. Ser. 8, 55, 559–564 (1973)

    Google Scholar 

  • Mancino, G., Ragghianti, M., Bucci-Innocenti, S., Cytotaxonomy and cytogenetics in European newt species. In: The reproductive biology of amphibians (D.H. Taylor and S.I. Guttman, eds.), pp. 411–447. New York: Plenum Publishing Corp. 1977

    Google Scholar 

  • Maniatis, T., Jeffrey, A., Kleid, D.G., Nukleotide sequence of the right-ward operator of phage λ. Proc. nat. Acad. Sci. (Wash.) 72, 1184–1188 (1975)

    Google Scholar 

  • Morgan, G.T., Absence of chiasmata from the heteromorphic region of chromosome I during spermatogenesis in Triturus cristatus carnifex. Chromosoma (Berl.) 66, 269–280 (1978)

    Google Scholar 

  • Nardi, L, Barsacchi-Pilone, G., Batistoni, R., Andronico, F., Chromosome location of the ribosomal RNA genes in Triturus vulgaris meridionalis (Amphibia, Urodela). II. Intraspecific variabilityin number and position of the chromosome loci for 18S and 28S ribosomal RNA. Chromosoma (Berl) 64, 67–84 (1977)

    Google Scholar 

  • Old, R.W., Callan, H.G., Gross, K.W., Localization of histone gene transcripts in newt lampbrush chromosomes by in situ hybridization. J. Cell Sci. 27, 57–79 (1977)

    Google Scholar 

  • Pardue, M.L., Gall, J.G., Nucleic acid hybridization to the DNA of cytological preparations. In: Methods in cell biology, 10 (D. Prescott, ed.), pp. 1–16. New York: Academic Press 1975

  • Pukkila, P.J., Identification of the lampbrush chromosome loops which transcribe 5S ribosomal RNA in Notophthalmus (Triturus) viridescens. Chromosoma (Berl.) 53, 71–89 (1975)

    Google Scholar 

  • Roeder, R.G., Eukaryotic nuclear RNA polymerases. In: RNA polymerase (R. Losick and M. Chamberlin, eds.) pp. 285–329. Cold Spr. Harb. Laboratory 1976

  • Rudak, E., Callan, H.G., Differential staining and chromatin packing of the mitotic chromosomes of the newt Triturus cristatus. Chromosoma (Berl.) 56, 349–362 (1976)

    Google Scholar 

  • Stephenson, E.M., Robinson, E.S. Stephenson, N.S., Karyotype variation within the genus Leiopelma (Amphibia:Anura). Canad. J. Genet. Cytol. 14, 691–702 (1972)

    Google Scholar 

  • Varley, J.M., Morgan, G.T., Silver staining of the lampbrush chromosomes of Triturus cristatus carnifex. Chromosoma (Berl.) 67, 233–244 (1978)

    Google Scholar 

  • Varley, J.M., Macgregor, H.C., Erba, H.P., Satellite DNA is transcribed on lampbrush chromosomes. Nature (Lond.) 283, 686–688 (1980a)

    Google Scholar 

  • Varley, J.M., Macgregor, H.C., Nardi, I., Andrews, C., Erba, H.P., Cytological evidence of transcription of highly repeated DNA sequences during the lampbrush stage in Triturus cristatus carnifex. Chromosoma (Berl.), (1980b)

  • Vlad, M., Quantitative studies of rDNA in amphibians. J. Cell Sci. 24, 109–118 (1977)

    Google Scholar 

  • Wickbom, T., Cytological studies on Dipnoi, Urodela, Anura, and Emys. Hereditas (Lund.) 31, 241–345 (1945)

    Google Scholar 

Download references

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Morgan, G.T., Macgregor, H.C. & Colman, A. Multiple ribosomal gene sites revealed by in situ hybridization of Xenopus rDNA to Tritums lampbrush chromosomes. Chromosoma 80, 309–330 (1980). https://doi.org/10.1007/BF00292687

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