Abstract
Seven natural populations of the grasshopper Aiolopus strepens were analysed to investigate the effects of a pericentric inversion in the smallest chromosome (S11) on chiasma formation and nucleolus organizer regions (NORs) activity. This polymorphism was stable in one population after comparing the frequencies of standard and inverted S11 chromosomes in two samples taken 5 years apart. Furthermore, mean cell chiasma frequency in this population tended to decrease over these 5 years. Males homozygous for the S11 inversion showed a higher frequency of inactivity of one of the NORs located on the L3 chromosome than that found in standard homozygous and heterozygous males. The results suggest that this stable polymorphism is maintained by heterosis, and that inversion homozygotes are less fit than standard homozygotes, which explains the low frequency of inverted chromosomes in all populations analysed. However, the possibility of recurrence of the inversion cannot be ruled out.
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Cabrero, J, Alche, J D, and Camacho, J P M. 1987. Effects of B chromosomes of the grasshopper Eyprepocnemis plorans on nucleolar organiser regions activity. Activation of a latent NOR on a B chromosome fused to an autosome. Genome, 29, 116–121.
Cabrero, J, and Camacho, J P M. 1982. Pericentric inversion polymorphism in Aiolopus strepens (Orthoptera: Acrididae): effects on chiasma formation. Caryologia, 35, 4, 411–424.
Cabrero, J, and Camacho, J P M. 1987. Inbreeding in a natural population of the grasshopper Chorthippus nevadensis. Heredity, 58, 57–58.
Hewitt, G M. 1979. Grasshoppers and Crickets Animal Cytogenetics, Vol. 3: Insecta 1 Orthoptera, Gebrüder Borntraeger, Berlin.
Lewontin, R C, and White, M J D. 1960. Interaction between inversion polymorphisms of two chromosome pairs in the grasshopper Moraba scurra. Evolution, 14, 116–129.
Rufas, J S, Iturra, P, De Souza, W, and Esponda, P. 1982. Simple silver staining procedure for the location of nucleolus and nucleolar organizer under light and electron microscopy. Arch Biol, 93, 267–274.
Salcedo, F J, Viseras, E, and Camacho, J P M. 1988. The B-chromosomes of Locusta migratoria. III. Effects on the activity of nucleolar organizer regions. Genome, 30, 387–394.
Suja, J A, Camacho, J P M, Cabrero, J, and Rufas, J S. 1986. Analysis of a centric shift in the S11 chromosome of Aiolopus strepens (Orthoptera: Acrididae). Genetica, 70, 211–216.
White, M J D. 1958. Restrictions on recombination in grasshopper populations and species. Cold Spr Harb Symp Quant Biol, 23, 307–317.
White, M J D. 1961. Cytogenetics of the grasshopper Moraba scurra. VI. A spontaneous pericentric inversion. Aust J Zool, 9, 784–790.
White, M J D. 1963. Cytogenetics of the grasshopper Moraba scurra. VIII. A complex spontaneous translocation. Chromosoma, 14, 140–145.
White, M J D. 1973. Animal Cytology and Evolution, 3rd edn, Cambridge University Press, London.
White, M J D, Lewontin, R C, and Andrew, L E. 1963. Cytogenetics of the grasshopper Moraba scurra. VII. Geographic variation of adaptive properties of inversions. Evolution, 17, 147–162.
Acknowledgements
This work was partially supported by grants from the Direccion General de Investigation Cientifica y Técnica (no. PB87-0886) and Plan Andaluz de Investigation, Grupo no. 3094 (Spain).
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Viseras, E., Camacho, J. Effects and maintenance of a pericentric inversion polymorphism in the grasshopper Aiolopus strepens. Heredity 66, 325–331 (1991). https://doi.org/10.1038/hdy.1991.41
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DOI: https://doi.org/10.1038/hdy.1991.41
