Abstract
DNA reassociation kinetics were studied, by means of the hydroxyapatite chromatography method, for four species of Amphibians with different nuclear DNA content: Xenopus laevis (3 pg DNA per haploid genome) and Bufo bufo (7 pg) of the Anura subclass and Trituras cristatus (23 pg) and Necturus maculosus (52 pg) of the Urodela subclass.
Within each subclass the two species studied were found to have about the same absolute amount of unique DNA. The differences of total nuclear DNA can be accounted for by quantitative variations of the repetitive sequence classes, at least in part due to changes in the number of copies of the various sequences. On the contrary the great difference in nuclear DNA between the two subclasses, Anura and Urodela, involves all sequence classes in parallel; the slowly reassociating fraction appears to be unique in spite of a tenfold difference in absolute amount.
The dependence of reassociation kinetics on DNA fragment length for the four species indicates for all of them an interspersed organization of the various sequence classes.
Similar content being viewed by others
References
Amaldi, F., Lava-Sanchez, P.A., Buongiorno-Nardelli, M.: Redundancy of genetic information and evolution in living systems. Rend. Ace. Naz. Lincei S 8; 58, 939–944 (1975)
Britten, R.J., Kohne, D.E.: Repeated Sequences in DNA. Science 161, 529–540 (1968)
Britten, R.J., Davidson, E.H.: Gene regulation for higher cells: a theory. Science 165, 349–357 (1969)
Buongiorno-Nardelli, M., Amaldi, F., Lava-Sanchez, P.A.: Amplification as a rectification mechanism for the redundant rRNA genes. Nature (Lond.) New Biol. 238, 134–137 (1972)
Davidson, E.H., Hough, B.R., Amenson, C.S., Britten, R.J.: General interspersion of repetitive with nonrepetitive sequence elements in the DNA of Xenopus. J. molec. Biol. 77, 1–23 (1973)
Davis, R., Simon, M., Davidson, N.: Electron microscope heteroduplex methods for mapping regions of base sequence homology in nucleic acids. In: Methods in enzimology (L. Grossman and K. Moldave, eds.) 21, 413–428. New York: Academic Press 1971
Flavell, R.B., Bennet, M.D., Smith, J.B., Smith, D.B.: Genome size and the proportion of repeated nucleotide sequence DNA in plants. Biochem. Genet. 12, 257–269 (1974)
Hinegardner, R., Rosen, D.E.: Cellular DNA content and the evolution of Teleostean Fishes. Amer. Naturalist 106, 621–644 (1972)
Mizuno, S., Macgregor, H.C.: Chromosomes, DNA sequences and evolution in salamanders of the genus Plethodon. Chromosoma (Berl.) 48, 239–296 (1974)
Morescalchi, A., Serra, V.: DNA renaturation kinetics in some paedogenetic Urodeles. Experientia (Basel) 30, 487–89 (1974)
Morescalchi, A.: Amphibia. In: Cytotaxonomy and vertebrate evolution (A.B. Chiarelli and E. Capanna, eds.), pp. 233–348. London and New York: Academic Press 1973
Narayan, R.K.J., Rees, H.: Nuclear DNA variation in Lathyrus. Chromosoma (Berl.) 54, 141–154 (1976)
Ohno, S., Wolf, U., Atkin, N.B.: Evolution from Fishes to Mammals by gene duplication. Hereditas (Lund) 59, 169–187 (1968)
Olmo, E.: Quantitative variations in the nuclear DNA and phylogenesis of the Amphibia. Caryologia (Firenze) 26, 43–68 (1973)
Straus, N.A.: Comparative DNA renaturation kinetics in Amphibians. Proc. nat. Acad. Sci. (Wash.) 68, 799–802 (1971)
Studier, S.W.: Sedimentation studies of the size and shape of DNA. J. molec. Biol. 11, 373–390 (1965)
Wetmur, J.G., Davidson, N.: Kinetics of renaturation of DNA. J. molec. Biol. 31, 349–370 (1968)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Baldari, C.T., Amaldi, F. DNA reassociation kinetics in relation to genome size in four amphibian species. Chromosoma 59, 13–22 (1976). https://doi.org/10.1007/BF00327706
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00327706