Abstract
In Xenopus laevis eight tRNA genes are located in a 3.18 kb tandemly repeated unit. There are 150 copies of the unit at a single locus near the long arm telomere of one of the acrocentric chromosomes in the 14–17 group. Two additional classes of tRNA gene-containing repeats have been isolated (defined by clones p3.1 and p3.2) that have structures related to that of the 3.18 kb unit. Using in situ hybridization at the electron microscopic level, the p3.2 repeats are found clustered at a single locus in the subtelomeric region on one of the submetacentric chromosomes, whereas the p3.1 repeats are clustered at a locus indistinguishable from that containing the 3.18 kb repeats. This suggests that these tDNA tandem repeats can diverge in sequence from each other without being at distantly separated loci.
Similar content being viewed by others
References
Clarkson SG (1983) Transfer RNA genes. In: Maclean N, Gregory SP, Flavell RA (eds) Eukaryotic genes: their structure, activity and regulation. Butterworths, London, pp 239–261
Clarkson SG, Kurer V (1976) Isolation and some properties of DNA coding for tRNA met1 from Xenopus laevis. Cell 8: 183–195
Clarkson SG, Birnstiel ML, Purdom IF (1973a) Clustering of transfer RNA genes of Xenopus laevis. J Mol Biol 79:411–429
Clarkson SG, Birnstiel ML, Serra V (1973b) Reiterated transfer RNA genes of Xenopus laevis. J Mol Biol 79:391–410
Doering JL, Jelachich ML, Hanlon KM (1982) Identification and genomic organization of human tRNALys genes. FEBS Lett 146:47–51
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
Gouiloud E, Clarkson SG (1986) A dispersed tyrosine tRNA gene from Xenopus laevis with high transcriptional activity in vitro. J Biol Chem 261:486–494
Marcais B, Laurent A-M, Charlieu J-P, Roizes G (1993) Organization of the variant domains of α satellite DNA on human chromosome 21. J Mol Evol 37:171–178
Muller F, Clarkson SG (1980) Nucleotide sequence of genes coding for tRNAPhe and tRNATyr from a repeating unit of X. laevis DNA. Cell 19:345–353
Muller F, Clarkson SG, Galas DJ (1987) Sequence of a 3.18 kb tandem repeat of Xenopus laevis DNA containing 8 tRNA genes. Nucleic Acids Res 15:7191
Narayanswami S, Dvorkin N, Hamkalo BA (1992) Localization of nucleic acid sequences by EM in situ hybridization to whole mounts of chromosomes and nuclei. Methods Cell Biol 35: 110–132
Peterson RC, Doering JL, Brown DD (1980) Characterization of two Xenopus somatic 5S DNAs and one minor oocyte-specific 5S DNA. Cell 20:131–141
Reed KC, Mann DA (1985) Rapid transfer of DNA from agarose gels to nylon membranes. Nucleic Acids Res 13:7207–7221
Rosenthal DS, Doering JL (1983) The genomic organization of dispersed tRNA and 5S RNA genes in Xenopus laevis. J Biol Chem 258:7402–7410
Rosenthal DS, Doering JL, Fokta FJ, Jeske JB (1984) Two new tDNA families in Xenopus laevis. J Cell Biol 99:253a
Schmid M, Steinlein C (1991) Chromosome banding in Amphibia XVI. High resolution replication banding patterns in Xenopus laevis. chromosoma 101:123–132
Sims MA, Doering JL, Hoyle HD (1983) DNA methylation patterns in the 5S DNAs of Xenopus laevis. Nucleic Acids Res 11:277–290
Smith G (1976) Evolution of repeated DNA sequences by unequal crossover. Science 191:528–535
Stutz F, Gouilloud E, Clarkson SG (1989) Oocyte and somatic tyrosine tRNA genes in Xenopus laevis. Genes Dev 3:1190–1198
Warburton PE, Willard HF (1990) Genomic analysis of sequence variation in tandemly repeated DNA. Evidence for localized homogeneous sequence domains within arrays of α-satellite DNA. J Mol Biol 216:3–16
Wevrick R, Willard HF (1991) Physical map of the centromeric region of human chromosome 7: relationship between two distinct alpha satellite arrays. Nucleic Acids Res 19:2295–2301
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Narayanswami, S., Doering, J.L., Fokta, F.J. et al. Chromosomal locations of major tRNA gene clusters of Xenopus laevis . Chromosoma 104, 68–74 (1995). https://doi.org/10.1007/BF00352227
Received:
Revised:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00352227