Abstract
Details are given of a technique for making permanent preparations of the lampbrush chromosomes of Xenopus laevis. Stained preparations allow all 18 bivalent chromosomes to be identified, and a working map showing the major features has been constructed. Fifteen of the Xenopus chromosomes have one telomere conspicuously larger than the other; the two smallest chromosomes, and one other, lack large telomeres. Similar preparations, extracted with RNase and denatured, have been hybridized in situ with a 3H-labelled 5S cRNA probe. Chromosomes can be identified in the resulting autoradiographs. 5S DNA sequences are present at all the larger telomeres and at three of the smaller ones, but are absent from the telomeres at both ends of the two smallest chromosomes. There are also five interstitial sites of hybridization. At one of these, label is on the chromosome axis; at the other four, label extends well away from the axis.
Similar content being viewed by others
References
Baker JR (1946) Cytological technique, 2nd ed. Methuen, London, Wiley, New York, p 157
Barsacchi-Pilone G, Nardi I, Batistoni R, Andronico F, Beccari E (1974) Chromosome location of the genes for 28S, 18S and 5S ribosomal RNA in Trituras marmoratus (Amphibia Urodela). Chromosoma 49:135–153
Bonner JJ, Pardue ML (1976) Ecdysone-stimulated RNA synthesis in imaginal discs of Drosophila melanogaster. Chromosoma 58:87–99
Callan HG (1986) Lampbrush chromosomes. Springer, Berlin Heidelberg New York Tokyo, p 26
Davidson EH (1986) Gene activity in early development, 3rd ed. Academic Press, New York
Diaz MO, Gall JG (1985) Giant readthrough transcription units at the histone loci on lampbrush chromosomes of the newt Nothophthalmus. Chromosoma 92:243–253
Dumont JN (1972) Oogenesis in Xenopus laevis (Daudin) 1. Stages of oocyte development in laboratory maintained animals. J Morphol 136:153–180
Fedoroff NV, Brown DD (1978) The nucleotide sequence of oocyte 5S DNA in Xenopus laevis. 1. The AT-rich spacer. Cell 13:701–716
Fostel J, Narayanswami S, Hamkalo B, Clarkson SG, Pardue ML (1984) Chromosomal location of a major tRNA gene cluster of Xenopus laevis. Chromosoma 90:254–260
Gall JG, Stephenson EC, Erba HP, Diaz MO, Barsacchi-Pilone G (1981) Histone genes are located at the sphere loci of newt lampbrush chromosomes. Chromosoma 84:159–171
Guinta DR, Tso JY, Narayanswami S, Hamkalo B, Korn LJ (1986) Early replication and expression of oocyte-type 5S RNA genes in a Xenopus somatic cell line carrying a translocation. Proc Natl Acad Sci USA 83:5150–5154
Harper ME, Price J, Korn LJ (1983) Chromosomal mapping of Xenopus 5S genes: Somatic-type versus oocyte-type. Nucleic Acids Res 11:2313–2323
Hutchison N, Pardue ML (1975) The mitotic chromosomes of Notophthalmus (Triturus) viridescens: location of C banding regions and DNA sequences complementary to 18S, 28S and 5S ribosomal RNA. Chromosoma 53:51–69
Jamrich M, Warrior R, Steele R, Gall JG (1983) Transcription of repetitive sequences on Xenopus lampbrush chromosomes. Proc Natl Acad Sci USA 80:3364–3367
Macgregor HC, Varley JM (1983) Working with animal chromosomes. Wiley, New York, p 150
Müller WP (1974) The lampbrush chromosomes of Xenopus laevis (Daudin). Chromosoma 47:283–296
Pardue ML, Brown DD, Birnstiel ML (1973) Location of the genes for 5S ribosomal RNA in Xenopus laevis. Chromosoma 42:191–203
Pukkila PJ (1975) Identification of the lampbrush chromosome loops which transcribe 5S ribosomal RNA in Notophthalmus (Triturus) viridescens. Chromosoma 53:71–89
Rogers AW (1979) Techniques of autoradiography, 3rd ed. Elsevier, North Holland, pp 134–135
Schultz LD, Kay BK, Gall JG (1981) In vitro RNA synthesis in oocyte nuclei of the newt Notophthalmus. Chromosoma 82:171–187
Tymowska J, Kobel HR (1972) Karyotype analysis of Xenopus muelleri (Peters) and Xenopus laevis (Daudin), Pipidae. Cytogenetics 11:270–278
Wallace RA, Jared DW, Dumont JN, Sega MW (1973) Protein incorporation by isolated amphibian oocytes III. Optimum incubation conditions. J Exp Zool 184:321–333
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Callan, H.G., Gall, J.G. & Berg, C.A. The lampbrush chromosomes of Xenopus laevis: preparation, identification, and distribution of 5S DNA sequences. Chromosoma 95, 236–250 (1987). https://doi.org/10.1007/BF00294780
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00294780