Abstract
The DNAs of the two subspecies ofChironomus thummi, Ch. th. thummi andCh. th. piger, were investigated by CsCl density-gradient centrifugation, melting analysis and restriction analysis including Southern hybridization with AT-rich, highly repetitive DNA sequences. The melting analysis of density-fractionatedCh. th. thummi andCh. th. piger DNA has shown that thethummi DNA contains an early melting DNA fraction, which is enriched in the light fractions of the density gradient. The DNA fraction is also present inpiger DNA though in lower concentration. Restriction and Southern analysis of density fractionatedthummi andpiger DNA has revealed that there are two tandemly-repetitive DNA-sequence families that hybridize with this AT-rich, early melting DNA fraction. One sequence is characterized by anHae-III site and a basic repeat length of 130 ± 15 bp and the other by aCla-1 restriction site and a basic repeat length of 120 ± 4 bp. These sequences are present in much higher concentrations in the genome ofCh. th. thummi when compared toCh. th. piger, and are hence correlated to the higher DNA content of theCh. th. thummi genome.
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References
BernardiG., FauresM., PipernoG. & SlominskiP. P., 1970. Mitochondrial DNAs from respiratory-sufficient and cytoplasmic respiratory-deficient mutant yeast. J. mol. Biol. 48: 23–42.
BrutlagD. L., 1980. Molecular arrangement and evolution of heterochromatic DNA. Ann. Rev. Genet. 14: 121–144.
DenhardtD. T., 1966. A membrane-filter technique for the detection of complementary DNA. Biochem. biophys. Res. Commun. 23: 641–646.
KeylH.-G., 1965a. A demonstrable local and geometric increase in the chromosomal DNA of Chironomus. Experientia 21: 191–193.
KeylH.-G., 1965b. Duplikationen von Untereinheiten der chromosomalen DNS während der Evolution von Chironomus thummi. Chromosoma 17: 139–180.
McGregorH. C. & MizunoS., 1976. In situ hybridization of ‘nick-translated’3H-ribosomal DNA to chromosomes from salamanders. Chromosoma 54: 15–25.
SchaeferJ. & SchmidtE. R., 1981. Different repetition frequencies of a 120 base-pair DNA-element and its arrangement in Chironomus thummi thummi and Chironomus thummi piger. Chromosoma 84: 61–66.
SchmidtE. R., 1981. The development of a 120 basepair repetitive DNA sequence in Chironomus thummi is correlated to the duplication of defined chromosomal segments. FEBS-Lett. 129: 21–24.
SchmidtE. R., VistorinG. & KeylH.-G., 1980. An AT-rich DNA component in the genomes of Chironomus thummi thummi and Chironomus thummi piger. Chromosoma 76: 35–45.
SouthernE. M., 1975. Detection of specific sequences among DNA fragments separated by gel electrophoresis. J. mol. Biol. 98: 503–519.
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Vistorin, G., Schmidt, E.R. Analysis of a repetitive DNA family of two closely related chironomids,Chironomus thummi thummi andCh. thummi piger (Diptera) by density-gradient centrifugation, melting analysis and restriction analysis. Genetica 61, 75–79 (1983). https://doi.org/10.1007/BF00563234
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DOI: https://doi.org/10.1007/BF00563234