Abstract
Three species of the genus Stethophyma have been cytologically examined and all three show variation both for supernumerary heterochromatic segments and for the distribution of standard heterochromatin among the autosomes. The European species, S. grossum, for example, shows considerable interpopulation variation for standard heterochromatin while two of the populations, from Spain and Austria, show supernumerary segment polymorphism. The segments are located interstitially on the S11 chromosome but occupy different positions in the different populations. — In all species, the presence of the extra heterochromatic segments increases the mean chiasma frequency. Moreover, the influence of the segments upon mean chiasma frequency is different in different populations and in different species. In the Spanish population, the increase is both intra- and interchromosomal whereas in Austria the influence of the segment is completely interchromosomal. — In the American species, S. gracile and S. lineatum, where supernumerary heterochromatic segments are carried on both S10 and S11 chromosomes, the effect on chiasma frequency shows a dosage relationship, an increase in the number of segments per individual being correlated with an increase in mean chiasma frequency. It is suggested that the interstitial segments found in all species have originated by direct duplication of chromosome material. By contrast the terminal segments in S. lineatum and S. gracile may be derived by translocation from a B-chromosome since such a chromosome has been found in one individual of the former species. — The variation in segment structure and the distribution of standard heterochromatin, among the European species of S. grossum suggests that these systems have evolved independently in different populations.
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References
Blatchley, W. S.: Orthoptera of Northeastern America. Indianapolis: The Nature Publishing Co. 1920.
Cameron, F. M., Rees, H.: The influence of B chromosomes on meiosis in Lolium. Heredity 22, 446–450 (1967).
Carothers, E. E.: The maturation divisions and segregation of heteromorphic homologous chromosomes in Acrididae (Orthoptera). Biol. Bull. (Woods Hole) 61, 324–349 (1931).
Corey, H. I.: Heteropyonotic elements of Orthopteran chromosomes. Arch. Biol. France, Belgique 49, 159–172 (1938).
Darlington, C. D.: The evolution of genetic systems, 2nd ed. Edinburgh and London: Oliver and Boyd 1958.
—, Shaw, G. W.: Parallel polymorphism in the heterochromatin of Trillium species. Heredity 13, 89–121 (1959).
Haga, T.: Structure and dynamics of natural populations of a diploid Trillium. Chromosomes today, vol. 2, p. 207–217 (1969).
Henderson, S. A.: Chiasma localisation and incomplete pairing. Chromosomes today, vol. 2, p. 56–60 (1969).
Hewitt, G. M., John, B.: Parallel polymorphism for supernumerary segments in Chorthippus parallelus (Zetterstedt). I. British populations. Chromosoma (Berl.) 25, 319–342 (1968).
John, B., Henderson, S. A.: Asynapsis and polyploidy in Schistocerca paranensis. Chromosoma (Berl.) 13, 111–147 (1962).
—, Hewitt, G. M.: The B-chromosome system of Myrmeleotettix maculatus (Thumb.) Chromosoma (Berl.) 16, 548–578 (1965).
—: A polymorphism for heterochromatic supernumerary segments in Chorthippus parallelus. Chromosoma (Berl.) 18, 254–271 (1966).
—: Parallel polymorphism for supernumerary segments in Chorthippus parallelus (Zetterstedt). III. The Ashurst population. Chromosoma (Berl.) 28, 73–84 (1969).
—, Lewis, K. R.: The chromosome complement. Protoplasmatologia, vol. IV/A. Wien: Springer 1968.
Jones, R. N., Rees, H.: Genotypic control of chromosome behaviour in rye XI. The influence of B-chromosomes on meiosis. Heredity 22, 333–347 (1967).
McClung, C. E.: Differential chromosomes in Mecostethus gracilis. Z. Zellforsch. 7, 756–778 (1928).
Müntzing, A.: Cyto-genetics of accessory chromosomes (B-chromosomes). Caryologia (Firenze) 6, suppl., 282–301 (1954).
Ragge, D. R.: Grasshoppers, crickets and cockroaches of the British Isles. London: F. Warne 1965.
Shaw, D. D.: The supernumerary segment system of Stethophyma. I. Structural basis. Chromosoma (Berl.) 30, 326–343 (1970).
Smith, S. G.: Natural hybridization in the Coccinellid genus Chilocorus. Chromosoma (Berl.) 18, 380–406 (1966).
Westerman, M.: Parallel polymorphism for supernumerary segments in Chorthippus parallelus (Zetterstedt). II. French. populations. Chromosoma (Berl.) 26, 7–21. (1969).
White, M. J. D.: Chiasma localisation in Mecostethus grossus L. and Metrioptera brachyptem L. (Orthoptera). Z. Zellforsch. 24, 128–135 (1936).
—: Animal cytology and evolution, 2nd edit. Cambridge: Cambridge University Press 1954.
Zečević, L. J., Paunović, D.: The effect of B-chromosomes on chiasma frequency in wild populations of rye. Chromosoma (Berl.) 27, 198–200 (1969).
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On educational leave from the Forest Research Laboratory, Fredericton, N. B. Canada.
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Shaw, D.D. The supernumerary segment system of Stethophyma . Chromosoma 34, 19–39 (1971). https://doi.org/10.1007/BF00285514
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DOI: https://doi.org/10.1007/BF00285514