Abstract
The grasshopper Oedaleonotus enigma possesses a neo-XY sex system and the rest of the chromosome complement is highly polymorphic, suggesting recent chromosomal evolution. It contains a fusion between two telocentrics, a centric shift and an extra heterochromatic segment, all of which are polymorphic, and in addition it has B-chromosomes. The fusion polymorphism has a preponderance of heterokaryotypes, and despite frequent inbreeding the other two polymorphisms have binomial frequencies of heterokaryotypes. Male individuals with two neo-X chromosomes and no neo-Y (at least in the germ line) are discussed.
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References
Cain, A. J., and P. M. Sheppard: Natural selection in Cepaea. Genetics 39, 89–116 (1954).
Dobzhansky, Th.: Genetics and the origin of species, 3rd edit. New York: Columbia University Press 1951.
Ford, E. B.: Genetic polymorphism. All souls studies, 5. London: Faber & Faber, 1965.
Hewitt, G. M.: A tetrasomic mosaic in the germ line of Chorthippus parallelus. Heredity 18, 505–512 (1963).
—: An interchange which raises chiasma frequency. Chromosoma (Berl.) 21, 285–295 (1967).
John, B., and G. M. Hewitt: A polymorphism for heterochromatic supernumerary segments in Chorthippus parallelus. Chromosoma (Berl.) 18, 254–271 (1966).
—: Patterns, pathways and processes of chromosomal evolution in the Orthoptera. Chromosoma (Berl.) 25, 40–74 (1968).
King, R. L.: Neo Y chromosome in Hypochlora alba and Mermiria intertexta (Orthoptera acrididae). J. Morph. 87, 227–257 (1950).
Lewis, K. R., and B. John: Chromosome marker, p. 69–82. London: Churchill 1963.
Lindsten, J.: The nature and origin of X chromosome aberrations in Turner's syndrome. Uppsala: Almquist & Wiksell 1963.
Procunier, D., and D. T. Suzuki: Interchromosomal effects on crossingover in Drosophila melanogaster, 4. All compound X chromosomes. Canad. J. Genet. Cytol. 9, 874–879 (1967).
Saez, F. A.: Gradient of heterochromatinisation in the evolution of the sexual system “neo X — neo Y”. Port. Acta biol. A 7, 111–138 (1963).
Schroeter, G. L.: Ph. D. Thesis, University of California (1968).
Thompson, R. M., and G. A. Buxton: An index of the Acridoidea (Orthoptera) of California. Bureau of Entomology, California Department of Agriculture, occasional papers no 5, 1–62 (1964).
White, M. J. D.: Animal cytology and evolution, 2nd edit. Cambridge: University Press 1954.
—, and P. H. W. Morley: Effects of pericentric rearrangements on recombination in grasshopper chromosomes. Genetics 40, 604–619 (1955).
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Hewitt, G., Schroeter, G. Population cytology of Oedaleonotus . Chromosoma 25, 121–140 (1968). https://doi.org/10.1007/BF00327173
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DOI: https://doi.org/10.1007/BF00327173